CORROSION ISSUE IN WASTE WATER TREAMENT PLANT

Wastewater treatment plant (WWTP) components generally experience both atmospheric and immersion corrosion The corrosion intensive components include buried piping handrails gratingsladders electrical junction boxes clarifier rake arms concrete walls etc Hydrogen sulfide which is usually present has wide-ranging effects in wastewater systems most notably causing corrosion and odor problemsSevere immersion corrosion of WWTP components were recently identified in and around theprimary and secondary clarifiers at two Army Installations The corroding components included rake arms weir and other metallic components such as skimmers and valve handles Also the concrete clarifier structure itself has shown sign of deterioration In addition steel lamp posts within the vicinityof one of the wastewater treatment plant were found to be corroding due to hydrogen sulfide in the atmosphere in addition to moisture and high humidityThe corrosion problems have been mitigated by a combination of strategies including judiciousselection and implementation of emerging corrosion resistant coatings corrosion resistant materials selection and cathode protection For example impressed current cathodic protection using ceramic anodes has been employed for protection of the immersed metallic components in several clarifiersNon-volatile 100 solids environmentally compatible coal tar epoxy coatings are being used on lamp post within the WWTP and corrosion resistant steels alloys are being substituted as corrosion resistantAlternatives for low carbon steel in valve handles and electrical junction boxes and polymers are being implemented in electrical junction boxes The benefits of the implementing corrosion controlTechnologies at the wastewater treatment plants are restoration of the plant to optimum operating condition reduced maintenance and increased safety

CAUSES OF CORROSION AT WASTEWATER TREATMENT PLANTS

Raw sewage is a source of hydrogen sulfide and has wide-ranging effects Hydrogen sulfide is released from the surface of the wastewater enters the atmosphere of the sewer and is oxidized on the surface of the of the wastewater treatment plant components The oxidation of hydrogen sulfide results in the production of sulfuric acid as follows

H2S + 2O2 rarr H2SO4

As a result of this reaction moist areas become acidic and corrosion of metallic components proceeds rapidly Steel and other ferrous alloys and copper are especially susceptible to this form of corrosionNormal oxidation (rusting) of ferrous materials may be accelerated in the presence of sulfuric acid up to 10 times the calculated corrosion rate due to oxidation aloneThe sulfuric acid attacks concrete structures by dissolving cement bonding materials forming a pasty mass which falls away and exposes more material to be attacked Corrosion rates depend on sulfide concentration in the sewer rate of release of H2S from the surface of the wastewater streamand turbulence which promotes higher than normal off-gassing conditions Turbulence in Headworks and grit tanks can cause mist or splash to occur on the wall area immediately above the water surfaceThe mist zone is most susceptible to corrosion Areas above this zone are usually kept dry ifventilation is provided or if the facilities are open to the atmosphere Areas of turbulence and splash for example weirs and troughs are often corroded in primary clarifiers Secondary clarifiers are typically not subject to H2S corrosion because sulfide concentrations in them are very low usually unmeasurable

Sulfide Production Rate

The rate at which sulfide is produced by a slime layer on collection pipes depends on the following environmental conditions

Concentrations of organic matter and nutrients Sulfate concentration Dissolved Oxygen (DO) pH Temperature Stream Velocity Surface area Retention time

Corrosion mechanism in waste water treatment plant

As one would suppose the environment of a sewage collection system is one of the least sterile imaginablePerversely it is the very lack of sterility that at once makes the system workas efficiently as it does and that is the cause of myriad problems The process begins with decomposition of solid wastes in the sewage To travel from any particular home or building on thesystem to the wastewater treatment plant (WWTP) requires several days on average During this time anaerobic bacteria which function in an airless environment are present in the solid wastes along with water-aided dissolution and agitation due to flowing and tumbling through the pipeline These factors cause the waste solids to break up The microbes release hydrogen sulfide (H2S) as they form sulfate-containing organic compoundsThe bacterial digestion of the solids forms polythionates and other sulfates Water

Waste solids + microbes = H2S + polythionates + sulfates Agitation

some of which are deposited on the concreteIn the air spaces above the sewagewater vapor (H2O) and carbon dioxide(CO2) are ubiquitous Collecting on theconcrete the condensed H2O dissolves both the CO2 and H2S resulting in a solution of H2S and carbonic acid (H2CO3)Metals are also used in various ways throughout wastewater treatment systems Concrete usually contains metallic reinforcement (rebar) Ladders sluice gates and other metallic substrates offer opportunities for corrosion Microbiologically influenced corrosion (MIC) on metals is no different than any other electrochemical attack The microorganisms involved can cause the same sort of corrosion problems seen in other environmentsThey may accelerate corrosion from other sources such as industrial discharges Corrosion phenomena such as pitting gaseous concentration cells crevice corrosion exfoliationand selective de-alloying are all found with MIC

Areas in Wastewater Collection and Treatment Systems Prone to Corrosion

bull Manholesbull Lift StationsPumping Stationsbull Grit Chambersbull Junction Boxesbull Drop Manholesbull Digestersbull Clarifiersbull Sludge Housesbull Wet Wellsbull Aeration Basins

Cabinet large valves andvertical pumps located in the general area ofthe primary clarifiers showing an exampleof general surface corrosion (WWTP)

Above ground piping located inthe general area of the primary clarifiers Notethe rubber gasket material for the pipe flangeset (WWTP)

Sludge thickener tankrsquosrdquo rakearm There was virtually no coating on thesteel associated with the rake arm (WWTP)

PRODUCTS FOR RESTORATION AND PROTECTION OF WASTEWATER INFRASTRUCTURES

LININGS ndash INFILTRATION AND CORROSION PROTECTION

SewerGard Epoxy SystemsSelf priming moisture tolerant epoxy systems that are completely resistant to the micro-biologically induced corrosion common to municipal wastewater applications as well as provide an infiltration barrier They are available in aggregate filled trowel (No 210T) and rotary spray (No 210RS) versions as well as a

fiber-filled airless spray version (No 210S) The No 210RS allows manholes to be efficiently lined from street level with minimal entry into the manhole These products will bond to damp concrete and cure in the presence of moisture An optional topcoat (210G) provides a more smooth surface for greater cleanability This 100 solids product can be economicallyrolled or sprayed

SewerSeal No F-170

Single component high strength 100 calcium aluminate based product for use in manholes and other wastewater structures This material will restore structural integrity prevent infiltration and resist mild acids and alkalies on concrete brick and steel structures SewerSeal is designed for rotary and straight shot spray applications and can be applied at various thicknessrsquo in one pass

H2OPruf No F-190

Two component cementitious based negative side waterproofing system specifically designed to withstand hydrostatic pressures that cause water seepage in below grade structures Two 116-inch coats will withstand up to 70 feet of water head pressure It can be applied by brush or spray including rotary spray equipment used for manholes

SUBSTRATE REPAIR

Underlayment and Repair Mortar No F-120

Single component high strength rapid set Portland cement based repair mortar that is available in trowel castable and gunite gradesThe trowel grade can be applied vertically and overhead and can be topcoated with epoxy in 5 hours

Substrate Resurfacer No F-121

Single component high strength rapid set Portland cement based product for repairing resurfacing and waterproofing masonry structuresThis material will restore structural integrity and prevent water infiltration into concrete and brick structures It is designed for rotary and straight shot spray applications and can be applied at various thicknesses in one pass

Filler Compound No 209

Three component epoxy formulation that is specifically designed to fill voids irregularities and air pockets in concrete No 209 will provide a smooth surface ready for application of protective compounds in 3 hours This material is also available in a fast setting grade that can be topcoated in 1 hour Either formulation is suitable for application over damp or dry concrete Application is performed with a rubber KampR trowel

ACTIVE INFLOW AND WATERSTOP PRODUCTS

Manhole ChimneySeal No F-88

Elastomeric lining composed of fiber-reinforced asphalt-modified urethane Two component chemical resistant seal that can be applied by a gloved hand onto the chimney sections of manholes to prevent water inflow As a high solids elastomer Chimney Seal maintains excellent elasticity and adhesion over a temperature range of -301048722F to 2501048722F while resisting acids alkalies and salts

InstaPlug No F-180

Rapid setting hydraulic water plug that will seal active water leaks and allow continuous rehabilitation work on concrete structures This material will set in 60 ndash 90 seconds and cure completely in

one hour It is also used to fill small voids and for anchoring applications

Hydroactive Polyurethane Grout No F-370

Catalyzed hydrophobic grout that reacts with moisture and expands to 20 times its volume to seal leaks cracks joints and voids It bonds tenaciously to practically any substrate wet or dry it has excellent chemical resistance and it is safe for potable water

SPECIALTY

PenePrime No 500

Two component water-borne epoxy primer that is specially formulated to work in conjunction with other Sauereisen products PenePrime penetrates deep into the concrete substrate to seal porous substrates and reduce off-gassing from concrete This product is manufactured to ensure maximum adhesion of the specified protective coating Application is performed by brush roll or spray

Microbiological Influenced Corrosion

What is MIC

There are biological organisms (microbes) which influence corrosion The primary and to many the only concern is that this influence often results in an extremely accelerated rate of corrosion It affects most alloys such as ductile iron steel (including stainless and galvanized) and copper but it doesnt seem to affect titanium The affect does vary between the different alloys with ductile iron corroding slower than steel There was also a case where MIC caused the water in copper pipe to turn blue

MIC is not caused by a single microbe but is attributed to many different microbes These are often categorized by common characteristics such as by-products (ie sludge producing) or compounds they effect (ie sulfur oxidizing) In a general sense they all fall into one of two groups based upon their oxygen requirements one being aerobic (requires oxygen) such as sulfur oxidizing bacteria and the other being anaerobic (requires little or no oxygen) such as sulfate reducing bacteria

General corrosion affects the entire surface or at least the wetted surface MIC on the other hand is very localized It creates a nodule and a pit beneath the nodule There can be only a few nodules or there can be many Within these nodules microbes rarely work alone but operate as a mixed community of differing types and groups The different microbes perform different functions within the community This interaction allows a community to thrive in environments that are actually hostile to some of its members For example in an aerobic environment anaerobic bacteria are generally inhibited or killed But within a community the aerobic bacteria reside in the outer layer of the nodule consuming the oxygen in the water as it penetrates the nodule Thus the inner portion of the nodule experiences a reduced oxygen level allowing anaerobic bacteria to thrive

Types of microorganism that produce MIC

Acid Producing Bacteria (APBrsquos-Aerobic or Facultative Anaerobic)

Sulfate-reducing Bacteria (SRBrsquos) Iron or Manganese Bacteria Slime Formers

How MIC Works

As already identified MIC operates as an individual nodule covering a pit The development of this process occurs in three phases which are

Attachment of microbes Growth of nodule and initial pit Mature pit and nodule

Phase One Obviously for MIC to occur the microbes must be introduced into the sprinkler system Even though a nodule can contain many different bacteria they do not necessarily arrive andor thrive simultaneously In order for microbes to attach themselves to the inner wall of the pipe the bacteria must find a desirable site Such sites are defined as containing absorbed nutrients and having a metallurgical feature that the microbes can attach to These features seem to be critical for MIC to occur and consist of irregularities in the pipe surface such as from welded connection pipe seams pre-existing corrosion inclusions etc

After successfully attaching to a location Phase Two starts a lot occurs at this stage (Actually only a fraction of the activity is shown since there can be an immense amount of chemical interaction occurring) Among the microbes by-products are sticky polymers which retain organic and inorganic materials aiding in the creation of the nodule Once the nodule is formed it allows the underlying conditions to become chemically dissimilar to the surrounding surface This is the start of accelerated corrosion which initially leads to crevice corrosion Some of the characteristics of the community at this phase are microbes are located throughout the nodule and the pH level is lowered (acidic) within the crevice but it is still above 4 This lower pH adds to the corrosiveness of the environment as well

as stimulating the growth of certain types of bacteria The increased acidic level is commonly initiated by acid-producing bacteria which produce organic acids as a by-product This acid provides a nutrient source for other bacteria whose by-product results in a buildup of hydrogen protons and an even lower pH level

In the final phas there is continued formation of the nodule over a mature pit Such a pit not only increases in depth but also produces a tunneling characteristic A significant condition is that the pH is less than 4 One of the factors which can contribute to the high acidic level is the weak organic acids discussed in Phase Two These can be converted to a stronger acid by combining with chloride from the water thus producing hydrochloric acid As a result of the high acidity in the pit area live bacteria are present only in the outer portion of the nodule At this point the bacteria could be eliminated and the corrosion would continue as a traditional electrochemical corrosion process Because of a better understanding of the final phase whereby the presence of the bacteria is not required the name was changed from microbiological induced corrosion to microbiological influenced corrosion

How to identify MIC

Experts need to use all three of the following confirmation tests to identify MIC

Chemical-Test directly for pH organic acids and test indirectly (test byproducts) for iron sulfide

Biological-Several methods available The most common are the MIC Field Kit andor microbiological culturing (Requires 28 days or more to produce results)

Metallurgical-Visually identify shiny metal underneath corrosion products

Minimizing MIC

bull Routine inspectionsbull Clean environmentbull Design of the bargebull Barrier Systembull Chemical Treatments Through Green Chemistrybull Maintain the Coating Systembull Other methods

CAUSES OF CORROSION AT WASTEWATER TREATMENT PLANTS

Raw sewage is a source of hydrogen sulfide and has wide-ranging effects Hydrogen sulfide is released from the surface of the wastewater enters the atmosphere of the sewer and is oxidized on the surface of the of the wastewater treatment plant components The oxidation of hydrogen sulfide results in the production of sulfuric acid as follows

H2S + 2O2 rarr H2SO4

As a result of this reaction moist areas become acidic and corrosion of metallic components proceeds rapidly Steel and other ferrous alloys and copper are especially susceptible to this form of corrosionNormal oxidation (rusting) of ferrous materials may be accelerated in the presence of sulfuric acid up to 10 times the calculated corrosion rate due to oxidation aloneThe sulfuric acid attacks concrete structures by dissolving cement bonding materials forming a pasty mass which falls away and exposes more material to be attacked Corrosion rates depend on sulfide concentration in the sewer rate of release of H2S from the surface of the wastewater streamand turbulence which promotes higher than normal off-gassing conditions Turbulence in Headworks and grit tanks can cause mist or splash to occur on the wall area immediately above the water surfaceThe mist zone is most susceptible to corrosion Areas above this zone are usually kept dry ifventilation is provided or if the facilities are open to the atmosphere Areas of turbulence and splash for example weirs and troughs are often corroded in primary clarifiers Secondary clarifiers are typically not subject to H2S corrosion because sulfide concentrations in them are very low usually unmeasurable

Sulfide Production Rate

The rate at which sulfide is produced by a slime layer on collection pipes depends on the following environmental conditions

Concentrations of organic matter and nutrients Sulfate concentration Dissolved Oxygen (DO) pH Temperature Stream Velocity Surface area Retention time

Corrosion mechanism in waste water treatment plant

As one would suppose the environment of a sewage collection system is one of the least sterile imaginablePerversely it is the very lack of sterility that at once makes the system workas efficiently as it does and that is the cause of myriad problems The process begins with decomposition of solid wastes in the sewage To travel from any particular home or building on thesystem to the wastewater treatment plant (WWTP) requires several days on average During this time anaerobic bacteria which function in an airless environment are present in the solid wastes along with water-aided dissolution and agitation due to flowing and tumbling through the pipeline These factors cause the waste solids to break up The microbes release hydrogen sulfide (H2S) as they form sulfate-containing organic compoundsThe bacterial digestion of the solids forms polythionates and other sulfates Water

Waste solids + microbes = H2S + polythionates + sulfates Agitation

some of which are deposited on the concreteIn the air spaces above the sewagewater vapor (H2O) and carbon dioxide(CO2) are ubiquitous Collecting on theconcrete the condensed H2O dissolves both the CO2 and H2S resulting in a solution of H2S and carbonic acid (H2CO3)Metals are also used in various ways throughout wastewater treatment systems Concrete usually contains metallic reinforcement (rebar) Ladders sluice gates and other metallic substrates offer opportunities for corrosion Microbiologically influenced corrosion (MIC) on metals is no different than any other electrochemical attack The microorganisms involved can cause the same sort of corrosion problems seen in other environmentsThey may accelerate corrosion from other sources such as industrial discharges Corrosion phenomena such as pitting gaseous concentration cells crevice corrosion exfoliationand selective de-alloying are all found with MIC

Areas in Wastewater Collection and Treatment Systems Prone to Corrosion

bull Manholesbull Lift StationsPumping Stationsbull Grit Chambersbull Junction Boxesbull Drop Manholesbull Digestersbull Clarifiersbull Sludge Housesbull Wet Wellsbull Aeration Basins

Cabinet large valves andvertical pumps located in the general area ofthe primary clarifiers showing an exampleof general surface corrosion (WWTP)

Above ground piping located inthe general area of the primary clarifiers Notethe rubber gasket material for the pipe flangeset (WWTP)

Sludge thickener tankrsquosrdquo rakearm There was virtually no coating on thesteel associated with the rake arm (WWTP)

PRODUCTS FOR RESTORATION AND PROTECTION OF WASTEWATER INFRASTRUCTURES

LININGS ndash INFILTRATION AND CORROSION PROTECTION

SewerGard Epoxy SystemsSelf priming moisture tolerant epoxy systems that are completely resistant to the micro-biologically induced corrosion common to municipal wastewater applications as well as provide an infiltration barrier They are available in aggregate filled trowel (No 210T) and rotary spray (No 210RS) versions as well as a

fiber-filled airless spray version (No 210S) The No 210RS allows manholes to be efficiently lined from street level with minimal entry into the manhole These products will bond to damp concrete and cure in the presence of moisture An optional topcoat (210G) provides a more smooth surface for greater cleanability This 100 solids product can be economicallyrolled or sprayed

SewerSeal No F-170

Single component high strength 100 calcium aluminate based product for use in manholes and other wastewater structures This material will restore structural integrity prevent infiltration and resist mild acids and alkalies on concrete brick and steel structures SewerSeal is designed for rotary and straight shot spray applications and can be applied at various thicknessrsquo in one pass

H2OPruf No F-190

Two component cementitious based negative side waterproofing system specifically designed to withstand hydrostatic pressures that cause water seepage in below grade structures Two 116-inch coats will withstand up to 70 feet of water head pressure It can be applied by brush or spray including rotary spray equipment used for manholes

SUBSTRATE REPAIR

Underlayment and Repair Mortar No F-120

Single component high strength rapid set Portland cement based repair mortar that is available in trowel castable and gunite gradesThe trowel grade can be applied vertically and overhead and can be topcoated with epoxy in 5 hours

Substrate Resurfacer No F-121

Single component high strength rapid set Portland cement based product for repairing resurfacing and waterproofing masonry structuresThis material will restore structural integrity and prevent water infiltration into concrete and brick structures It is designed for rotary and straight shot spray applications and can be applied at various thicknesses in one pass

Filler Compound No 209

Three component epoxy formulation that is specifically designed to fill voids irregularities and air pockets in concrete No 209 will provide a smooth surface ready for application of protective compounds in 3 hours This material is also available in a fast setting grade that can be topcoated in 1 hour Either formulation is suitable for application over damp or dry concrete Application is performed with a rubber KampR trowel

ACTIVE INFLOW AND WATERSTOP PRODUCTS

Manhole ChimneySeal No F-88

Elastomeric lining composed of fiber-reinforced asphalt-modified urethane Two component chemical resistant seal that can be applied by a gloved hand onto the chimney sections of manholes to prevent water inflow As a high solids elastomer Chimney Seal maintains excellent elasticity and adhesion over a temperature range of -301048722F to 2501048722F while resisting acids alkalies and salts

InstaPlug No F-180

Rapid setting hydraulic water plug that will seal active water leaks and allow continuous rehabilitation work on concrete structures This material will set in 60 ndash 90 seconds and cure completely in

one hour It is also used to fill small voids and for anchoring applications

Hydroactive Polyurethane Grout No F-370

Catalyzed hydrophobic grout that reacts with moisture and expands to 20 times its volume to seal leaks cracks joints and voids It bonds tenaciously to practically any substrate wet or dry it has excellent chemical resistance and it is safe for potable water

SPECIALTY

PenePrime No 500

Two component water-borne epoxy primer that is specially formulated to work in conjunction with other Sauereisen products PenePrime penetrates deep into the concrete substrate to seal porous substrates and reduce off-gassing from concrete This product is manufactured to ensure maximum adhesion of the specified protective coating Application is performed by brush roll or spray

Microbiological Influenced Corrosion

What is MIC

There are biological organisms (microbes) which influence corrosion The primary and to many the only concern is that this influence often results in an extremely accelerated rate of corrosion It affects most alloys such as ductile iron steel (including stainless and galvanized) and copper but it doesnt seem to affect titanium The affect does vary between the different alloys with ductile iron corroding slower than steel There was also a case where MIC caused the water in copper pipe to turn blue

MIC is not caused by a single microbe but is attributed to many different microbes These are often categorized by common characteristics such as by-products (ie sludge producing) or compounds they effect (ie sulfur oxidizing) In a general sense they all fall into one of two groups based upon their oxygen requirements one being aerobic (requires oxygen) such as sulfur oxidizing bacteria and the other being anaerobic (requires little or no oxygen) such as sulfate reducing bacteria

General corrosion affects the entire surface or at least the wetted surface MIC on the other hand is very localized It creates a nodule and a pit beneath the nodule There can be only a few nodules or there can be many Within these nodules microbes rarely work alone but operate as a mixed community of differing types and groups The different microbes perform different functions within the community This interaction allows a community to thrive in environments that are actually hostile to some of its members For example in an aerobic environment anaerobic bacteria are generally inhibited or killed But within a community the aerobic bacteria reside in the outer layer of the nodule consuming the oxygen in the water as it penetrates the nodule Thus the inner portion of the nodule experiences a reduced oxygen level allowing anaerobic bacteria to thrive

Types of microorganism that produce MIC

Acid Producing Bacteria (APBrsquos-Aerobic or Facultative Anaerobic)

Sulfate-reducing Bacteria (SRBrsquos) Iron or Manganese Bacteria Slime Formers

How MIC Works

As already identified MIC operates as an individual nodule covering a pit The development of this process occurs in three phases which are

Attachment of microbes Growth of nodule and initial pit Mature pit and nodule

Phase One Obviously for MIC to occur the microbes must be introduced into the sprinkler system Even though a nodule can contain many different bacteria they do not necessarily arrive andor thrive simultaneously In order for microbes to attach themselves to the inner wall of the pipe the bacteria must find a desirable site Such sites are defined as containing absorbed nutrients and having a metallurgical feature that the microbes can attach to These features seem to be critical for MIC to occur and consist of irregularities in the pipe surface such as from welded connection pipe seams pre-existing corrosion inclusions etc

After successfully attaching to a location Phase Two starts a lot occurs at this stage (Actually only a fraction of the activity is shown since there can be an immense amount of chemical interaction occurring) Among the microbes by-products are sticky polymers which retain organic and inorganic materials aiding in the creation of the nodule Once the nodule is formed it allows the underlying conditions to become chemically dissimilar to the surrounding surface This is the start of accelerated corrosion which initially leads to crevice corrosion Some of the characteristics of the community at this phase are microbes are located throughout the nodule and the pH level is lowered (acidic) within the crevice but it is still above 4 This lower pH adds to the corrosiveness of the environment as well

as stimulating the growth of certain types of bacteria The increased acidic level is commonly initiated by acid-producing bacteria which produce organic acids as a by-product This acid provides a nutrient source for other bacteria whose by-product results in a buildup of hydrogen protons and an even lower pH level

In the final phas there is continued formation of the nodule over a mature pit Such a pit not only increases in depth but also produces a tunneling characteristic A significant condition is that the pH is less than 4 One of the factors which can contribute to the high acidic level is the weak organic acids discussed in Phase Two These can be converted to a stronger acid by combining with chloride from the water thus producing hydrochloric acid As a result of the high acidity in the pit area live bacteria are present only in the outer portion of the nodule At this point the bacteria could be eliminated and the corrosion would continue as a traditional electrochemical corrosion process Because of a better understanding of the final phase whereby the presence of the bacteria is not required the name was changed from microbiological induced corrosion to microbiological influenced corrosion

How to identify MIC

Experts need to use all three of the following confirmation tests to identify MIC

Chemical-Test directly for pH organic acids and test indirectly (test byproducts) for iron sulfide

Biological-Several methods available The most common are the MIC Field Kit andor microbiological culturing (Requires 28 days or more to produce results)

Metallurgical-Visually identify shiny metal underneath corrosion products

Minimizing MIC

bull Routine inspectionsbull Clean environmentbull Design of the bargebull Barrier Systembull Chemical Treatments Through Green Chemistrybull Maintain the Coating Systembull Other methods

Sulfide Production Rate

The rate at which sulfide is produced by a slime layer on collection pipes depends on the following environmental conditions

Concentrations of organic matter and nutrients Sulfate concentration Dissolved Oxygen (DO) pH Temperature Stream Velocity Surface area Retention time

Corrosion mechanism in waste water treatment plant

As one would suppose the environment of a sewage collection system is one of the least sterile imaginablePerversely it is the very lack of sterility that at once makes the system workas efficiently as it does and that is the cause of myriad problems The process begins with decomposition of solid wastes in the sewage To travel from any particular home or building on thesystem to the wastewater treatment plant (WWTP) requires several days on average During this time anaerobic bacteria which function in an airless environment are present in the solid wastes along with water-aided dissolution and agitation due to flowing and tumbling through the pipeline These factors cause the waste solids to break up The microbes release hydrogen sulfide (H2S) as they form sulfate-containing organic compoundsThe bacterial digestion of the solids forms polythionates and other sulfates Water

Waste solids + microbes = H2S + polythionates + sulfates Agitation

some of which are deposited on the concreteIn the air spaces above the sewagewater vapor (H2O) and carbon dioxide(CO2) are ubiquitous Collecting on theconcrete the condensed H2O dissolves both the CO2 and H2S resulting in a solution of H2S and carbonic acid (H2CO3)Metals are also used in various ways throughout wastewater treatment systems Concrete usually contains metallic reinforcement (rebar) Ladders sluice gates and other metallic substrates offer opportunities for corrosion Microbiologically influenced corrosion (MIC) on metals is no different than any other electrochemical attack The microorganisms involved can cause the same sort of corrosion problems seen in other environmentsThey may accelerate corrosion from other sources such as industrial discharges Corrosion phenomena such as pitting gaseous concentration cells crevice corrosion exfoliationand selective de-alloying are all found with MIC

Areas in Wastewater Collection and Treatment Systems Prone to Corrosion

bull Manholesbull Lift StationsPumping Stationsbull Grit Chambersbull Junction Boxesbull Drop Manholesbull Digestersbull Clarifiersbull Sludge Housesbull Wet Wellsbull Aeration Basins

Cabinet large valves andvertical pumps located in the general area ofthe primary clarifiers showing an exampleof general surface corrosion (WWTP)

Above ground piping located inthe general area of the primary clarifiers Notethe rubber gasket material for the pipe flangeset (WWTP)

Sludge thickener tankrsquosrdquo rakearm There was virtually no coating on thesteel associated with the rake arm (WWTP)

PRODUCTS FOR RESTORATION AND PROTECTION OF WASTEWATER INFRASTRUCTURES

LININGS ndash INFILTRATION AND CORROSION PROTECTION

SewerGard Epoxy SystemsSelf priming moisture tolerant epoxy systems that are completely resistant to the micro-biologically induced corrosion common to municipal wastewater applications as well as provide an infiltration barrier They are available in aggregate filled trowel (No 210T) and rotary spray (No 210RS) versions as well as a

fiber-filled airless spray version (No 210S) The No 210RS allows manholes to be efficiently lined from street level with minimal entry into the manhole These products will bond to damp concrete and cure in the presence of moisture An optional topcoat (210G) provides a more smooth surface for greater cleanability This 100 solids product can be economicallyrolled or sprayed

SewerSeal No F-170

Single component high strength 100 calcium aluminate based product for use in manholes and other wastewater structures This material will restore structural integrity prevent infiltration and resist mild acids and alkalies on concrete brick and steel structures SewerSeal is designed for rotary and straight shot spray applications and can be applied at various thicknessrsquo in one pass

H2OPruf No F-190

Two component cementitious based negative side waterproofing system specifically designed to withstand hydrostatic pressures that cause water seepage in below grade structures Two 116-inch coats will withstand up to 70 feet of water head pressure It can be applied by brush or spray including rotary spray equipment used for manholes

SUBSTRATE REPAIR

Underlayment and Repair Mortar No F-120

Single component high strength rapid set Portland cement based repair mortar that is available in trowel castable and gunite gradesThe trowel grade can be applied vertically and overhead and can be topcoated with epoxy in 5 hours

Substrate Resurfacer No F-121

Single component high strength rapid set Portland cement based product for repairing resurfacing and waterproofing masonry structuresThis material will restore structural integrity and prevent water infiltration into concrete and brick structures It is designed for rotary and straight shot spray applications and can be applied at various thicknesses in one pass

Filler Compound No 209

Three component epoxy formulation that is specifically designed to fill voids irregularities and air pockets in concrete No 209 will provide a smooth surface ready for application of protective compounds in 3 hours This material is also available in a fast setting grade that can be topcoated in 1 hour Either formulation is suitable for application over damp or dry concrete Application is performed with a rubber KampR trowel

ACTIVE INFLOW AND WATERSTOP PRODUCTS

Manhole ChimneySeal No F-88

Elastomeric lining composed of fiber-reinforced asphalt-modified urethane Two component chemical resistant seal that can be applied by a gloved hand onto the chimney sections of manholes to prevent water inflow As a high solids elastomer Chimney Seal maintains excellent elasticity and adhesion over a temperature range of -301048722F to 2501048722F while resisting acids alkalies and salts

InstaPlug No F-180

Rapid setting hydraulic water plug that will seal active water leaks and allow continuous rehabilitation work on concrete structures This material will set in 60 ndash 90 seconds and cure completely in

one hour It is also used to fill small voids and for anchoring applications

Hydroactive Polyurethane Grout No F-370

Catalyzed hydrophobic grout that reacts with moisture and expands to 20 times its volume to seal leaks cracks joints and voids It bonds tenaciously to practically any substrate wet or dry it has excellent chemical resistance and it is safe for potable water

SPECIALTY

PenePrime No 500

Two component water-borne epoxy primer that is specially formulated to work in conjunction with other Sauereisen products PenePrime penetrates deep into the concrete substrate to seal porous substrates and reduce off-gassing from concrete This product is manufactured to ensure maximum adhesion of the specified protective coating Application is performed by brush roll or spray

Microbiological Influenced Corrosion

What is MIC

There are biological organisms (microbes) which influence corrosion The primary and to many the only concern is that this influence often results in an extremely accelerated rate of corrosion It affects most alloys such as ductile iron steel (including stainless and galvanized) and copper but it doesnt seem to affect titanium The affect does vary between the different alloys with ductile iron corroding slower than steel There was also a case where MIC caused the water in copper pipe to turn blue

MIC is not caused by a single microbe but is attributed to many different microbes These are often categorized by common characteristics such as by-products (ie sludge producing) or compounds they effect (ie sulfur oxidizing) In a general sense they all fall into one of two groups based upon their oxygen requirements one being aerobic (requires oxygen) such as sulfur oxidizing bacteria and the other being anaerobic (requires little or no oxygen) such as sulfate reducing bacteria

General corrosion affects the entire surface or at least the wetted surface MIC on the other hand is very localized It creates a nodule and a pit beneath the nodule There can be only a few nodules or there can be many Within these nodules microbes rarely work alone but operate as a mixed community of differing types and groups The different microbes perform different functions within the community This interaction allows a community to thrive in environments that are actually hostile to some of its members For example in an aerobic environment anaerobic bacteria are generally inhibited or killed But within a community the aerobic bacteria reside in the outer layer of the nodule consuming the oxygen in the water as it penetrates the nodule Thus the inner portion of the nodule experiences a reduced oxygen level allowing anaerobic bacteria to thrive

Types of microorganism that produce MIC

Acid Producing Bacteria (APBrsquos-Aerobic or Facultative Anaerobic)

Sulfate-reducing Bacteria (SRBrsquos) Iron or Manganese Bacteria Slime Formers

How MIC Works

As already identified MIC operates as an individual nodule covering a pit The development of this process occurs in three phases which are

Attachment of microbes Growth of nodule and initial pit Mature pit and nodule

Phase One Obviously for MIC to occur the microbes must be introduced into the sprinkler system Even though a nodule can contain many different bacteria they do not necessarily arrive andor thrive simultaneously In order for microbes to attach themselves to the inner wall of the pipe the bacteria must find a desirable site Such sites are defined as containing absorbed nutrients and having a metallurgical feature that the microbes can attach to These features seem to be critical for MIC to occur and consist of irregularities in the pipe surface such as from welded connection pipe seams pre-existing corrosion inclusions etc

After successfully attaching to a location Phase Two starts a lot occurs at this stage (Actually only a fraction of the activity is shown since there can be an immense amount of chemical interaction occurring) Among the microbes by-products are sticky polymers which retain organic and inorganic materials aiding in the creation of the nodule Once the nodule is formed it allows the underlying conditions to become chemically dissimilar to the surrounding surface This is the start of accelerated corrosion which initially leads to crevice corrosion Some of the characteristics of the community at this phase are microbes are located throughout the nodule and the pH level is lowered (acidic) within the crevice but it is still above 4 This lower pH adds to the corrosiveness of the environment as well

as stimulating the growth of certain types of bacteria The increased acidic level is commonly initiated by acid-producing bacteria which produce organic acids as a by-product This acid provides a nutrient source for other bacteria whose by-product results in a buildup of hydrogen protons and an even lower pH level

In the final phas there is continued formation of the nodule over a mature pit Such a pit not only increases in depth but also produces a tunneling characteristic A significant condition is that the pH is less than 4 One of the factors which can contribute to the high acidic level is the weak organic acids discussed in Phase Two These can be converted to a stronger acid by combining with chloride from the water thus producing hydrochloric acid As a result of the high acidity in the pit area live bacteria are present only in the outer portion of the nodule At this point the bacteria could be eliminated and the corrosion would continue as a traditional electrochemical corrosion process Because of a better understanding of the final phase whereby the presence of the bacteria is not required the name was changed from microbiological induced corrosion to microbiological influenced corrosion

How to identify MIC

Experts need to use all three of the following confirmation tests to identify MIC

Chemical-Test directly for pH organic acids and test indirectly (test byproducts) for iron sulfide

Biological-Several methods available The most common are the MIC Field Kit andor microbiological culturing (Requires 28 days or more to produce results)

Metallurgical-Visually identify shiny metal underneath corrosion products

Minimizing MIC

bull Routine inspectionsbull Clean environmentbull Design of the bargebull Barrier Systembull Chemical Treatments Through Green Chemistrybull Maintain the Coating Systembull Other methods

Waste solids + microbes = H2S + polythionates + sulfates Agitation

some of which are deposited on the concreteIn the air spaces above the sewagewater vapor (H2O) and carbon dioxide(CO2) are ubiquitous Collecting on theconcrete the condensed H2O dissolves both the CO2 and H2S resulting in a solution of H2S and carbonic acid (H2CO3)Metals are also used in various ways throughout wastewater treatment systems Concrete usually contains metallic reinforcement (rebar) Ladders sluice gates and other metallic substrates offer opportunities for corrosion Microbiologically influenced corrosion (MIC) on metals is no different than any other electrochemical attack The microorganisms involved can cause the same sort of corrosion problems seen in other environmentsThey may accelerate corrosion from other sources such as industrial discharges Corrosion phenomena such as pitting gaseous concentration cells crevice corrosion exfoliationand selective de-alloying are all found with MIC

Areas in Wastewater Collection and Treatment Systems Prone to Corrosion

bull Manholesbull Lift StationsPumping Stationsbull Grit Chambersbull Junction Boxesbull Drop Manholesbull Digestersbull Clarifiersbull Sludge Housesbull Wet Wellsbull Aeration Basins

Cabinet large valves andvertical pumps located in the general area ofthe primary clarifiers showing an exampleof general surface corrosion (WWTP)

Above ground piping located inthe general area of the primary clarifiers Notethe rubber gasket material for the pipe flangeset (WWTP)

Sludge thickener tankrsquosrdquo rakearm There was virtually no coating on thesteel associated with the rake arm (WWTP)

PRODUCTS FOR RESTORATION AND PROTECTION OF WASTEWATER INFRASTRUCTURES

LININGS ndash INFILTRATION AND CORROSION PROTECTION

SewerGard Epoxy SystemsSelf priming moisture tolerant epoxy systems that are completely resistant to the micro-biologically induced corrosion common to municipal wastewater applications as well as provide an infiltration barrier They are available in aggregate filled trowel (No 210T) and rotary spray (No 210RS) versions as well as a

fiber-filled airless spray version (No 210S) The No 210RS allows manholes to be efficiently lined from street level with minimal entry into the manhole These products will bond to damp concrete and cure in the presence of moisture An optional topcoat (210G) provides a more smooth surface for greater cleanability This 100 solids product can be economicallyrolled or sprayed

SewerSeal No F-170

Single component high strength 100 calcium aluminate based product for use in manholes and other wastewater structures This material will restore structural integrity prevent infiltration and resist mild acids and alkalies on concrete brick and steel structures SewerSeal is designed for rotary and straight shot spray applications and can be applied at various thicknessrsquo in one pass

H2OPruf No F-190

Two component cementitious based negative side waterproofing system specifically designed to withstand hydrostatic pressures that cause water seepage in below grade structures Two 116-inch coats will withstand up to 70 feet of water head pressure It can be applied by brush or spray including rotary spray equipment used for manholes

SUBSTRATE REPAIR

Underlayment and Repair Mortar No F-120

Single component high strength rapid set Portland cement based repair mortar that is available in trowel castable and gunite gradesThe trowel grade can be applied vertically and overhead and can be topcoated with epoxy in 5 hours

Substrate Resurfacer No F-121

Single component high strength rapid set Portland cement based product for repairing resurfacing and waterproofing masonry structuresThis material will restore structural integrity and prevent water infiltration into concrete and brick structures It is designed for rotary and straight shot spray applications and can be applied at various thicknesses in one pass

Filler Compound No 209

Three component epoxy formulation that is specifically designed to fill voids irregularities and air pockets in concrete No 209 will provide a smooth surface ready for application of protective compounds in 3 hours This material is also available in a fast setting grade that can be topcoated in 1 hour Either formulation is suitable for application over damp or dry concrete Application is performed with a rubber KampR trowel

ACTIVE INFLOW AND WATERSTOP PRODUCTS

Manhole ChimneySeal No F-88

Elastomeric lining composed of fiber-reinforced asphalt-modified urethane Two component chemical resistant seal that can be applied by a gloved hand onto the chimney sections of manholes to prevent water inflow As a high solids elastomer Chimney Seal maintains excellent elasticity and adhesion over a temperature range of -301048722F to 2501048722F while resisting acids alkalies and salts

InstaPlug No F-180

Rapid setting hydraulic water plug that will seal active water leaks and allow continuous rehabilitation work on concrete structures This material will set in 60 ndash 90 seconds and cure completely in

one hour It is also used to fill small voids and for anchoring applications

Hydroactive Polyurethane Grout No F-370

Catalyzed hydrophobic grout that reacts with moisture and expands to 20 times its volume to seal leaks cracks joints and voids It bonds tenaciously to practically any substrate wet or dry it has excellent chemical resistance and it is safe for potable water

SPECIALTY

PenePrime No 500

Two component water-borne epoxy primer that is specially formulated to work in conjunction with other Sauereisen products PenePrime penetrates deep into the concrete substrate to seal porous substrates and reduce off-gassing from concrete This product is manufactured to ensure maximum adhesion of the specified protective coating Application is performed by brush roll or spray

Microbiological Influenced Corrosion

What is MIC

There are biological organisms (microbes) which influence corrosion The primary and to many the only concern is that this influence often results in an extremely accelerated rate of corrosion It affects most alloys such as ductile iron steel (including stainless and galvanized) and copper but it doesnt seem to affect titanium The affect does vary between the different alloys with ductile iron corroding slower than steel There was also a case where MIC caused the water in copper pipe to turn blue

MIC is not caused by a single microbe but is attributed to many different microbes These are often categorized by common characteristics such as by-products (ie sludge producing) or compounds they effect (ie sulfur oxidizing) In a general sense they all fall into one of two groups based upon their oxygen requirements one being aerobic (requires oxygen) such as sulfur oxidizing bacteria and the other being anaerobic (requires little or no oxygen) such as sulfate reducing bacteria

General corrosion affects the entire surface or at least the wetted surface MIC on the other hand is very localized It creates a nodule and a pit beneath the nodule There can be only a few nodules or there can be many Within these nodules microbes rarely work alone but operate as a mixed community of differing types and groups The different microbes perform different functions within the community This interaction allows a community to thrive in environments that are actually hostile to some of its members For example in an aerobic environment anaerobic bacteria are generally inhibited or killed But within a community the aerobic bacteria reside in the outer layer of the nodule consuming the oxygen in the water as it penetrates the nodule Thus the inner portion of the nodule experiences a reduced oxygen level allowing anaerobic bacteria to thrive

Types of microorganism that produce MIC

Acid Producing Bacteria (APBrsquos-Aerobic or Facultative Anaerobic)

Sulfate-reducing Bacteria (SRBrsquos) Iron or Manganese Bacteria Slime Formers

How MIC Works

As already identified MIC operates as an individual nodule covering a pit The development of this process occurs in three phases which are

Attachment of microbes Growth of nodule and initial pit Mature pit and nodule

Phase One Obviously for MIC to occur the microbes must be introduced into the sprinkler system Even though a nodule can contain many different bacteria they do not necessarily arrive andor thrive simultaneously In order for microbes to attach themselves to the inner wall of the pipe the bacteria must find a desirable site Such sites are defined as containing absorbed nutrients and having a metallurgical feature that the microbes can attach to These features seem to be critical for MIC to occur and consist of irregularities in the pipe surface such as from welded connection pipe seams pre-existing corrosion inclusions etc

After successfully attaching to a location Phase Two starts a lot occurs at this stage (Actually only a fraction of the activity is shown since there can be an immense amount of chemical interaction occurring) Among the microbes by-products are sticky polymers which retain organic and inorganic materials aiding in the creation of the nodule Once the nodule is formed it allows the underlying conditions to become chemically dissimilar to the surrounding surface This is the start of accelerated corrosion which initially leads to crevice corrosion Some of the characteristics of the community at this phase are microbes are located throughout the nodule and the pH level is lowered (acidic) within the crevice but it is still above 4 This lower pH adds to the corrosiveness of the environment as well

as stimulating the growth of certain types of bacteria The increased acidic level is commonly initiated by acid-producing bacteria which produce organic acids as a by-product This acid provides a nutrient source for other bacteria whose by-product results in a buildup of hydrogen protons and an even lower pH level

In the final phas there is continued formation of the nodule over a mature pit Such a pit not only increases in depth but also produces a tunneling characteristic A significant condition is that the pH is less than 4 One of the factors which can contribute to the high acidic level is the weak organic acids discussed in Phase Two These can be converted to a stronger acid by combining with chloride from the water thus producing hydrochloric acid As a result of the high acidity in the pit area live bacteria are present only in the outer portion of the nodule At this point the bacteria could be eliminated and the corrosion would continue as a traditional electrochemical corrosion process Because of a better understanding of the final phase whereby the presence of the bacteria is not required the name was changed from microbiological induced corrosion to microbiological influenced corrosion

How to identify MIC

Experts need to use all three of the following confirmation tests to identify MIC

Chemical-Test directly for pH organic acids and test indirectly (test byproducts) for iron sulfide

Biological-Several methods available The most common are the MIC Field Kit andor microbiological culturing (Requires 28 days or more to produce results)

Metallurgical-Visually identify shiny metal underneath corrosion products

Minimizing MIC

bull Routine inspectionsbull Clean environmentbull Design of the bargebull Barrier Systembull Chemical Treatments Through Green Chemistrybull Maintain the Coating Systembull Other methods

Cabinet large valves andvertical pumps located in the general area ofthe primary clarifiers showing an exampleof general surface corrosion (WWTP)

Above ground piping located inthe general area of the primary clarifiers Notethe rubber gasket material for the pipe flangeset (WWTP)

Sludge thickener tankrsquosrdquo rakearm There was virtually no coating on thesteel associated with the rake arm (WWTP)

PRODUCTS FOR RESTORATION AND PROTECTION OF WASTEWATER INFRASTRUCTURES

LININGS ndash INFILTRATION AND CORROSION PROTECTION

SewerGard Epoxy SystemsSelf priming moisture tolerant epoxy systems that are completely resistant to the micro-biologically induced corrosion common to municipal wastewater applications as well as provide an infiltration barrier They are available in aggregate filled trowel (No 210T) and rotary spray (No 210RS) versions as well as a

fiber-filled airless spray version (No 210S) The No 210RS allows manholes to be efficiently lined from street level with minimal entry into the manhole These products will bond to damp concrete and cure in the presence of moisture An optional topcoat (210G) provides a more smooth surface for greater cleanability This 100 solids product can be economicallyrolled or sprayed

SewerSeal No F-170

Single component high strength 100 calcium aluminate based product for use in manholes and other wastewater structures This material will restore structural integrity prevent infiltration and resist mild acids and alkalies on concrete brick and steel structures SewerSeal is designed for rotary and straight shot spray applications and can be applied at various thicknessrsquo in one pass

H2OPruf No F-190

Two component cementitious based negative side waterproofing system specifically designed to withstand hydrostatic pressures that cause water seepage in below grade structures Two 116-inch coats will withstand up to 70 feet of water head pressure It can be applied by brush or spray including rotary spray equipment used for manholes

SUBSTRATE REPAIR

Underlayment and Repair Mortar No F-120

Single component high strength rapid set Portland cement based repair mortar that is available in trowel castable and gunite gradesThe trowel grade can be applied vertically and overhead and can be topcoated with epoxy in 5 hours

Substrate Resurfacer No F-121

Single component high strength rapid set Portland cement based product for repairing resurfacing and waterproofing masonry structuresThis material will restore structural integrity and prevent water infiltration into concrete and brick structures It is designed for rotary and straight shot spray applications and can be applied at various thicknesses in one pass

Filler Compound No 209

Three component epoxy formulation that is specifically designed to fill voids irregularities and air pockets in concrete No 209 will provide a smooth surface ready for application of protective compounds in 3 hours This material is also available in a fast setting grade that can be topcoated in 1 hour Either formulation is suitable for application over damp or dry concrete Application is performed with a rubber KampR trowel

ACTIVE INFLOW AND WATERSTOP PRODUCTS

Manhole ChimneySeal No F-88

Elastomeric lining composed of fiber-reinforced asphalt-modified urethane Two component chemical resistant seal that can be applied by a gloved hand onto the chimney sections of manholes to prevent water inflow As a high solids elastomer Chimney Seal maintains excellent elasticity and adhesion over a temperature range of -301048722F to 2501048722F while resisting acids alkalies and salts

InstaPlug No F-180

Rapid setting hydraulic water plug that will seal active water leaks and allow continuous rehabilitation work on concrete structures This material will set in 60 ndash 90 seconds and cure completely in

one hour It is also used to fill small voids and for anchoring applications

Hydroactive Polyurethane Grout No F-370

Catalyzed hydrophobic grout that reacts with moisture and expands to 20 times its volume to seal leaks cracks joints and voids It bonds tenaciously to practically any substrate wet or dry it has excellent chemical resistance and it is safe for potable water

SPECIALTY

PenePrime No 500

Two component water-borne epoxy primer that is specially formulated to work in conjunction with other Sauereisen products PenePrime penetrates deep into the concrete substrate to seal porous substrates and reduce off-gassing from concrete This product is manufactured to ensure maximum adhesion of the specified protective coating Application is performed by brush roll or spray

Microbiological Influenced Corrosion

What is MIC

There are biological organisms (microbes) which influence corrosion The primary and to many the only concern is that this influence often results in an extremely accelerated rate of corrosion It affects most alloys such as ductile iron steel (including stainless and galvanized) and copper but it doesnt seem to affect titanium The affect does vary between the different alloys with ductile iron corroding slower than steel There was also a case where MIC caused the water in copper pipe to turn blue

MIC is not caused by a single microbe but is attributed to many different microbes These are often categorized by common characteristics such as by-products (ie sludge producing) or compounds they effect (ie sulfur oxidizing) In a general sense they all fall into one of two groups based upon their oxygen requirements one being aerobic (requires oxygen) such as sulfur oxidizing bacteria and the other being anaerobic (requires little or no oxygen) such as sulfate reducing bacteria

General corrosion affects the entire surface or at least the wetted surface MIC on the other hand is very localized It creates a nodule and a pit beneath the nodule There can be only a few nodules or there can be many Within these nodules microbes rarely work alone but operate as a mixed community of differing types and groups The different microbes perform different functions within the community This interaction allows a community to thrive in environments that are actually hostile to some of its members For example in an aerobic environment anaerobic bacteria are generally inhibited or killed But within a community the aerobic bacteria reside in the outer layer of the nodule consuming the oxygen in the water as it penetrates the nodule Thus the inner portion of the nodule experiences a reduced oxygen level allowing anaerobic bacteria to thrive

Types of microorganism that produce MIC

Acid Producing Bacteria (APBrsquos-Aerobic or Facultative Anaerobic)

Sulfate-reducing Bacteria (SRBrsquos) Iron or Manganese Bacteria Slime Formers

How MIC Works

As already identified MIC operates as an individual nodule covering a pit The development of this process occurs in three phases which are

Attachment of microbes Growth of nodule and initial pit Mature pit and nodule

Phase One Obviously for MIC to occur the microbes must be introduced into the sprinkler system Even though a nodule can contain many different bacteria they do not necessarily arrive andor thrive simultaneously In order for microbes to attach themselves to the inner wall of the pipe the bacteria must find a desirable site Such sites are defined as containing absorbed nutrients and having a metallurgical feature that the microbes can attach to These features seem to be critical for MIC to occur and consist of irregularities in the pipe surface such as from welded connection pipe seams pre-existing corrosion inclusions etc

After successfully attaching to a location Phase Two starts a lot occurs at this stage (Actually only a fraction of the activity is shown since there can be an immense amount of chemical interaction occurring) Among the microbes by-products are sticky polymers which retain organic and inorganic materials aiding in the creation of the nodule Once the nodule is formed it allows the underlying conditions to become chemically dissimilar to the surrounding surface This is the start of accelerated corrosion which initially leads to crevice corrosion Some of the characteristics of the community at this phase are microbes are located throughout the nodule and the pH level is lowered (acidic) within the crevice but it is still above 4 This lower pH adds to the corrosiveness of the environment as well

as stimulating the growth of certain types of bacteria The increased acidic level is commonly initiated by acid-producing bacteria which produce organic acids as a by-product This acid provides a nutrient source for other bacteria whose by-product results in a buildup of hydrogen protons and an even lower pH level

In the final phas there is continued formation of the nodule over a mature pit Such a pit not only increases in depth but also produces a tunneling characteristic A significant condition is that the pH is less than 4 One of the factors which can contribute to the high acidic level is the weak organic acids discussed in Phase Two These can be converted to a stronger acid by combining with chloride from the water thus producing hydrochloric acid As a result of the high acidity in the pit area live bacteria are present only in the outer portion of the nodule At this point the bacteria could be eliminated and the corrosion would continue as a traditional electrochemical corrosion process Because of a better understanding of the final phase whereby the presence of the bacteria is not required the name was changed from microbiological induced corrosion to microbiological influenced corrosion

How to identify MIC

Experts need to use all three of the following confirmation tests to identify MIC

Chemical-Test directly for pH organic acids and test indirectly (test byproducts) for iron sulfide

Biological-Several methods available The most common are the MIC Field Kit andor microbiological culturing (Requires 28 days or more to produce results)

Metallurgical-Visually identify shiny metal underneath corrosion products

Minimizing MIC

bull Routine inspectionsbull Clean environmentbull Design of the bargebull Barrier Systembull Chemical Treatments Through Green Chemistrybull Maintain the Coating Systembull Other methods

Above ground piping located inthe general area of the primary clarifiers Notethe rubber gasket material for the pipe flangeset (WWTP)

Sludge thickener tankrsquosrdquo rakearm There was virtually no coating on thesteel associated with the rake arm (WWTP)

PRODUCTS FOR RESTORATION AND PROTECTION OF WASTEWATER INFRASTRUCTURES

LININGS ndash INFILTRATION AND CORROSION PROTECTION

SewerGard Epoxy SystemsSelf priming moisture tolerant epoxy systems that are completely resistant to the micro-biologically induced corrosion common to municipal wastewater applications as well as provide an infiltration barrier They are available in aggregate filled trowel (No 210T) and rotary spray (No 210RS) versions as well as a

fiber-filled airless spray version (No 210S) The No 210RS allows manholes to be efficiently lined from street level with minimal entry into the manhole These products will bond to damp concrete and cure in the presence of moisture An optional topcoat (210G) provides a more smooth surface for greater cleanability This 100 solids product can be economicallyrolled or sprayed

SewerSeal No F-170

Single component high strength 100 calcium aluminate based product for use in manholes and other wastewater structures This material will restore structural integrity prevent infiltration and resist mild acids and alkalies on concrete brick and steel structures SewerSeal is designed for rotary and straight shot spray applications and can be applied at various thicknessrsquo in one pass

H2OPruf No F-190

Two component cementitious based negative side waterproofing system specifically designed to withstand hydrostatic pressures that cause water seepage in below grade structures Two 116-inch coats will withstand up to 70 feet of water head pressure It can be applied by brush or spray including rotary spray equipment used for manholes

SUBSTRATE REPAIR

Underlayment and Repair Mortar No F-120

Single component high strength rapid set Portland cement based repair mortar that is available in trowel castable and gunite gradesThe trowel grade can be applied vertically and overhead and can be topcoated with epoxy in 5 hours

Substrate Resurfacer No F-121

Single component high strength rapid set Portland cement based product for repairing resurfacing and waterproofing masonry structuresThis material will restore structural integrity and prevent water infiltration into concrete and brick structures It is designed for rotary and straight shot spray applications and can be applied at various thicknesses in one pass

Filler Compound No 209

Three component epoxy formulation that is specifically designed to fill voids irregularities and air pockets in concrete No 209 will provide a smooth surface ready for application of protective compounds in 3 hours This material is also available in a fast setting grade that can be topcoated in 1 hour Either formulation is suitable for application over damp or dry concrete Application is performed with a rubber KampR trowel

ACTIVE INFLOW AND WATERSTOP PRODUCTS

Manhole ChimneySeal No F-88

Elastomeric lining composed of fiber-reinforced asphalt-modified urethane Two component chemical resistant seal that can be applied by a gloved hand onto the chimney sections of manholes to prevent water inflow As a high solids elastomer Chimney Seal maintains excellent elasticity and adhesion over a temperature range of -301048722F to 2501048722F while resisting acids alkalies and salts

InstaPlug No F-180

Rapid setting hydraulic water plug that will seal active water leaks and allow continuous rehabilitation work on concrete structures This material will set in 60 ndash 90 seconds and cure completely in

one hour It is also used to fill small voids and for anchoring applications

Hydroactive Polyurethane Grout No F-370

Catalyzed hydrophobic grout that reacts with moisture and expands to 20 times its volume to seal leaks cracks joints and voids It bonds tenaciously to practically any substrate wet or dry it has excellent chemical resistance and it is safe for potable water

SPECIALTY

PenePrime No 500

Two component water-borne epoxy primer that is specially formulated to work in conjunction with other Sauereisen products PenePrime penetrates deep into the concrete substrate to seal porous substrates and reduce off-gassing from concrete This product is manufactured to ensure maximum adhesion of the specified protective coating Application is performed by brush roll or spray

Microbiological Influenced Corrosion

What is MIC

There are biological organisms (microbes) which influence corrosion The primary and to many the only concern is that this influence often results in an extremely accelerated rate of corrosion It affects most alloys such as ductile iron steel (including stainless and galvanized) and copper but it doesnt seem to affect titanium The affect does vary between the different alloys with ductile iron corroding slower than steel There was also a case where MIC caused the water in copper pipe to turn blue

MIC is not caused by a single microbe but is attributed to many different microbes These are often categorized by common characteristics such as by-products (ie sludge producing) or compounds they effect (ie sulfur oxidizing) In a general sense they all fall into one of two groups based upon their oxygen requirements one being aerobic (requires oxygen) such as sulfur oxidizing bacteria and the other being anaerobic (requires little or no oxygen) such as sulfate reducing bacteria

General corrosion affects the entire surface or at least the wetted surface MIC on the other hand is very localized It creates a nodule and a pit beneath the nodule There can be only a few nodules or there can be many Within these nodules microbes rarely work alone but operate as a mixed community of differing types and groups The different microbes perform different functions within the community This interaction allows a community to thrive in environments that are actually hostile to some of its members For example in an aerobic environment anaerobic bacteria are generally inhibited or killed But within a community the aerobic bacteria reside in the outer layer of the nodule consuming the oxygen in the water as it penetrates the nodule Thus the inner portion of the nodule experiences a reduced oxygen level allowing anaerobic bacteria to thrive

Types of microorganism that produce MIC

Acid Producing Bacteria (APBrsquos-Aerobic or Facultative Anaerobic)

Sulfate-reducing Bacteria (SRBrsquos) Iron or Manganese Bacteria Slime Formers

How MIC Works

As already identified MIC operates as an individual nodule covering a pit The development of this process occurs in three phases which are

Attachment of microbes Growth of nodule and initial pit Mature pit and nodule

Phase One Obviously for MIC to occur the microbes must be introduced into the sprinkler system Even though a nodule can contain many different bacteria they do not necessarily arrive andor thrive simultaneously In order for microbes to attach themselves to the inner wall of the pipe the bacteria must find a desirable site Such sites are defined as containing absorbed nutrients and having a metallurgical feature that the microbes can attach to These features seem to be critical for MIC to occur and consist of irregularities in the pipe surface such as from welded connection pipe seams pre-existing corrosion inclusions etc

After successfully attaching to a location Phase Two starts a lot occurs at this stage (Actually only a fraction of the activity is shown since there can be an immense amount of chemical interaction occurring) Among the microbes by-products are sticky polymers which retain organic and inorganic materials aiding in the creation of the nodule Once the nodule is formed it allows the underlying conditions to become chemically dissimilar to the surrounding surface This is the start of accelerated corrosion which initially leads to crevice corrosion Some of the characteristics of the community at this phase are microbes are located throughout the nodule and the pH level is lowered (acidic) within the crevice but it is still above 4 This lower pH adds to the corrosiveness of the environment as well

as stimulating the growth of certain types of bacteria The increased acidic level is commonly initiated by acid-producing bacteria which produce organic acids as a by-product This acid provides a nutrient source for other bacteria whose by-product results in a buildup of hydrogen protons and an even lower pH level

In the final phas there is continued formation of the nodule over a mature pit Such a pit not only increases in depth but also produces a tunneling characteristic A significant condition is that the pH is less than 4 One of the factors which can contribute to the high acidic level is the weak organic acids discussed in Phase Two These can be converted to a stronger acid by combining with chloride from the water thus producing hydrochloric acid As a result of the high acidity in the pit area live bacteria are present only in the outer portion of the nodule At this point the bacteria could be eliminated and the corrosion would continue as a traditional electrochemical corrosion process Because of a better understanding of the final phase whereby the presence of the bacteria is not required the name was changed from microbiological induced corrosion to microbiological influenced corrosion

How to identify MIC

Experts need to use all three of the following confirmation tests to identify MIC

Chemical-Test directly for pH organic acids and test indirectly (test byproducts) for iron sulfide

Biological-Several methods available The most common are the MIC Field Kit andor microbiological culturing (Requires 28 days or more to produce results)

Metallurgical-Visually identify shiny metal underneath corrosion products

Minimizing MIC

bull Routine inspectionsbull Clean environmentbull Design of the bargebull Barrier Systembull Chemical Treatments Through Green Chemistrybull Maintain the Coating Systembull Other methods

Sludge thickener tankrsquosrdquo rakearm There was virtually no coating on thesteel associated with the rake arm (WWTP)

PRODUCTS FOR RESTORATION AND PROTECTION OF WASTEWATER INFRASTRUCTURES

LININGS ndash INFILTRATION AND CORROSION PROTECTION

SewerGard Epoxy SystemsSelf priming moisture tolerant epoxy systems that are completely resistant to the micro-biologically induced corrosion common to municipal wastewater applications as well as provide an infiltration barrier They are available in aggregate filled trowel (No 210T) and rotary spray (No 210RS) versions as well as a

fiber-filled airless spray version (No 210S) The No 210RS allows manholes to be efficiently lined from street level with minimal entry into the manhole These products will bond to damp concrete and cure in the presence of moisture An optional topcoat (210G) provides a more smooth surface for greater cleanability This 100 solids product can be economicallyrolled or sprayed

SewerSeal No F-170

Single component high strength 100 calcium aluminate based product for use in manholes and other wastewater structures This material will restore structural integrity prevent infiltration and resist mild acids and alkalies on concrete brick and steel structures SewerSeal is designed for rotary and straight shot spray applications and can be applied at various thicknessrsquo in one pass

H2OPruf No F-190

Two component cementitious based negative side waterproofing system specifically designed to withstand hydrostatic pressures that cause water seepage in below grade structures Two 116-inch coats will withstand up to 70 feet of water head pressure It can be applied by brush or spray including rotary spray equipment used for manholes

SUBSTRATE REPAIR

Underlayment and Repair Mortar No F-120

Single component high strength rapid set Portland cement based repair mortar that is available in trowel castable and gunite gradesThe trowel grade can be applied vertically and overhead and can be topcoated with epoxy in 5 hours

Substrate Resurfacer No F-121

Single component high strength rapid set Portland cement based product for repairing resurfacing and waterproofing masonry structuresThis material will restore structural integrity and prevent water infiltration into concrete and brick structures It is designed for rotary and straight shot spray applications and can be applied at various thicknesses in one pass

Filler Compound No 209

Three component epoxy formulation that is specifically designed to fill voids irregularities and air pockets in concrete No 209 will provide a smooth surface ready for application of protective compounds in 3 hours This material is also available in a fast setting grade that can be topcoated in 1 hour Either formulation is suitable for application over damp or dry concrete Application is performed with a rubber KampR trowel

ACTIVE INFLOW AND WATERSTOP PRODUCTS

Manhole ChimneySeal No F-88

Elastomeric lining composed of fiber-reinforced asphalt-modified urethane Two component chemical resistant seal that can be applied by a gloved hand onto the chimney sections of manholes to prevent water inflow As a high solids elastomer Chimney Seal maintains excellent elasticity and adhesion over a temperature range of -301048722F to 2501048722F while resisting acids alkalies and salts

InstaPlug No F-180

Rapid setting hydraulic water plug that will seal active water leaks and allow continuous rehabilitation work on concrete structures This material will set in 60 ndash 90 seconds and cure completely in

one hour It is also used to fill small voids and for anchoring applications

Hydroactive Polyurethane Grout No F-370

Catalyzed hydrophobic grout that reacts with moisture and expands to 20 times its volume to seal leaks cracks joints and voids It bonds tenaciously to practically any substrate wet or dry it has excellent chemical resistance and it is safe for potable water

SPECIALTY

PenePrime No 500

Two component water-borne epoxy primer that is specially formulated to work in conjunction with other Sauereisen products PenePrime penetrates deep into the concrete substrate to seal porous substrates and reduce off-gassing from concrete This product is manufactured to ensure maximum adhesion of the specified protective coating Application is performed by brush roll or spray

Microbiological Influenced Corrosion

What is MIC

There are biological organisms (microbes) which influence corrosion The primary and to many the only concern is that this influence often results in an extremely accelerated rate of corrosion It affects most alloys such as ductile iron steel (including stainless and galvanized) and copper but it doesnt seem to affect titanium The affect does vary between the different alloys with ductile iron corroding slower than steel There was also a case where MIC caused the water in copper pipe to turn blue

MIC is not caused by a single microbe but is attributed to many different microbes These are often categorized by common characteristics such as by-products (ie sludge producing) or compounds they effect (ie sulfur oxidizing) In a general sense they all fall into one of two groups based upon their oxygen requirements one being aerobic (requires oxygen) such as sulfur oxidizing bacteria and the other being anaerobic (requires little or no oxygen) such as sulfate reducing bacteria

General corrosion affects the entire surface or at least the wetted surface MIC on the other hand is very localized It creates a nodule and a pit beneath the nodule There can be only a few nodules or there can be many Within these nodules microbes rarely work alone but operate as a mixed community of differing types and groups The different microbes perform different functions within the community This interaction allows a community to thrive in environments that are actually hostile to some of its members For example in an aerobic environment anaerobic bacteria are generally inhibited or killed But within a community the aerobic bacteria reside in the outer layer of the nodule consuming the oxygen in the water as it penetrates the nodule Thus the inner portion of the nodule experiences a reduced oxygen level allowing anaerobic bacteria to thrive

Types of microorganism that produce MIC

Acid Producing Bacteria (APBrsquos-Aerobic or Facultative Anaerobic)

Sulfate-reducing Bacteria (SRBrsquos) Iron or Manganese Bacteria Slime Formers

How MIC Works

As already identified MIC operates as an individual nodule covering a pit The development of this process occurs in three phases which are

Attachment of microbes Growth of nodule and initial pit Mature pit and nodule

Phase One Obviously for MIC to occur the microbes must be introduced into the sprinkler system Even though a nodule can contain many different bacteria they do not necessarily arrive andor thrive simultaneously In order for microbes to attach themselves to the inner wall of the pipe the bacteria must find a desirable site Such sites are defined as containing absorbed nutrients and having a metallurgical feature that the microbes can attach to These features seem to be critical for MIC to occur and consist of irregularities in the pipe surface such as from welded connection pipe seams pre-existing corrosion inclusions etc

After successfully attaching to a location Phase Two starts a lot occurs at this stage (Actually only a fraction of the activity is shown since there can be an immense amount of chemical interaction occurring) Among the microbes by-products are sticky polymers which retain organic and inorganic materials aiding in the creation of the nodule Once the nodule is formed it allows the underlying conditions to become chemically dissimilar to the surrounding surface This is the start of accelerated corrosion which initially leads to crevice corrosion Some of the characteristics of the community at this phase are microbes are located throughout the nodule and the pH level is lowered (acidic) within the crevice but it is still above 4 This lower pH adds to the corrosiveness of the environment as well

as stimulating the growth of certain types of bacteria The increased acidic level is commonly initiated by acid-producing bacteria which produce organic acids as a by-product This acid provides a nutrient source for other bacteria whose by-product results in a buildup of hydrogen protons and an even lower pH level

In the final phas there is continued formation of the nodule over a mature pit Such a pit not only increases in depth but also produces a tunneling characteristic A significant condition is that the pH is less than 4 One of the factors which can contribute to the high acidic level is the weak organic acids discussed in Phase Two These can be converted to a stronger acid by combining with chloride from the water thus producing hydrochloric acid As a result of the high acidity in the pit area live bacteria are present only in the outer portion of the nodule At this point the bacteria could be eliminated and the corrosion would continue as a traditional electrochemical corrosion process Because of a better understanding of the final phase whereby the presence of the bacteria is not required the name was changed from microbiological induced corrosion to microbiological influenced corrosion

How to identify MIC

Experts need to use all three of the following confirmation tests to identify MIC

Chemical-Test directly for pH organic acids and test indirectly (test byproducts) for iron sulfide

Biological-Several methods available The most common are the MIC Field Kit andor microbiological culturing (Requires 28 days or more to produce results)

Metallurgical-Visually identify shiny metal underneath corrosion products

Minimizing MIC

bull Routine inspectionsbull Clean environmentbull Design of the bargebull Barrier Systembull Chemical Treatments Through Green Chemistrybull Maintain the Coating Systembull Other methods

fiber-filled airless spray version (No 210S) The No 210RS allows manholes to be efficiently lined from street level with minimal entry into the manhole These products will bond to damp concrete and cure in the presence of moisture An optional topcoat (210G) provides a more smooth surface for greater cleanability This 100 solids product can be economicallyrolled or sprayed

SewerSeal No F-170

Single component high strength 100 calcium aluminate based product for use in manholes and other wastewater structures This material will restore structural integrity prevent infiltration and resist mild acids and alkalies on concrete brick and steel structures SewerSeal is designed for rotary and straight shot spray applications and can be applied at various thicknessrsquo in one pass

H2OPruf No F-190

Two component cementitious based negative side waterproofing system specifically designed to withstand hydrostatic pressures that cause water seepage in below grade structures Two 116-inch coats will withstand up to 70 feet of water head pressure It can be applied by brush or spray including rotary spray equipment used for manholes

SUBSTRATE REPAIR

Underlayment and Repair Mortar No F-120

Single component high strength rapid set Portland cement based repair mortar that is available in trowel castable and gunite gradesThe trowel grade can be applied vertically and overhead and can be topcoated with epoxy in 5 hours

Substrate Resurfacer No F-121

Single component high strength rapid set Portland cement based product for repairing resurfacing and waterproofing masonry structuresThis material will restore structural integrity and prevent water infiltration into concrete and brick structures It is designed for rotary and straight shot spray applications and can be applied at various thicknesses in one pass

Filler Compound No 209

Three component epoxy formulation that is specifically designed to fill voids irregularities and air pockets in concrete No 209 will provide a smooth surface ready for application of protective compounds in 3 hours This material is also available in a fast setting grade that can be topcoated in 1 hour Either formulation is suitable for application over damp or dry concrete Application is performed with a rubber KampR trowel

ACTIVE INFLOW AND WATERSTOP PRODUCTS

Manhole ChimneySeal No F-88

Elastomeric lining composed of fiber-reinforced asphalt-modified urethane Two component chemical resistant seal that can be applied by a gloved hand onto the chimney sections of manholes to prevent water inflow As a high solids elastomer Chimney Seal maintains excellent elasticity and adhesion over a temperature range of -301048722F to 2501048722F while resisting acids alkalies and salts

InstaPlug No F-180

Rapid setting hydraulic water plug that will seal active water leaks and allow continuous rehabilitation work on concrete structures This material will set in 60 ndash 90 seconds and cure completely in

one hour It is also used to fill small voids and for anchoring applications

Hydroactive Polyurethane Grout No F-370

Catalyzed hydrophobic grout that reacts with moisture and expands to 20 times its volume to seal leaks cracks joints and voids It bonds tenaciously to practically any substrate wet or dry it has excellent chemical resistance and it is safe for potable water

SPECIALTY

PenePrime No 500

Two component water-borne epoxy primer that is specially formulated to work in conjunction with other Sauereisen products PenePrime penetrates deep into the concrete substrate to seal porous substrates and reduce off-gassing from concrete This product is manufactured to ensure maximum adhesion of the specified protective coating Application is performed by brush roll or spray

Microbiological Influenced Corrosion

What is MIC

There are biological organisms (microbes) which influence corrosion The primary and to many the only concern is that this influence often results in an extremely accelerated rate of corrosion It affects most alloys such as ductile iron steel (including stainless and galvanized) and copper but it doesnt seem to affect titanium The affect does vary between the different alloys with ductile iron corroding slower than steel There was also a case where MIC caused the water in copper pipe to turn blue

MIC is not caused by a single microbe but is attributed to many different microbes These are often categorized by common characteristics such as by-products (ie sludge producing) or compounds they effect (ie sulfur oxidizing) In a general sense they all fall into one of two groups based upon their oxygen requirements one being aerobic (requires oxygen) such as sulfur oxidizing bacteria and the other being anaerobic (requires little or no oxygen) such as sulfate reducing bacteria

General corrosion affects the entire surface or at least the wetted surface MIC on the other hand is very localized It creates a nodule and a pit beneath the nodule There can be only a few nodules or there can be many Within these nodules microbes rarely work alone but operate as a mixed community of differing types and groups The different microbes perform different functions within the community This interaction allows a community to thrive in environments that are actually hostile to some of its members For example in an aerobic environment anaerobic bacteria are generally inhibited or killed But within a community the aerobic bacteria reside in the outer layer of the nodule consuming the oxygen in the water as it penetrates the nodule Thus the inner portion of the nodule experiences a reduced oxygen level allowing anaerobic bacteria to thrive

Types of microorganism that produce MIC

Acid Producing Bacteria (APBrsquos-Aerobic or Facultative Anaerobic)

Sulfate-reducing Bacteria (SRBrsquos) Iron or Manganese Bacteria Slime Formers

How MIC Works

As already identified MIC operates as an individual nodule covering a pit The development of this process occurs in three phases which are

Attachment of microbes Growth of nodule and initial pit Mature pit and nodule

Phase One Obviously for MIC to occur the microbes must be introduced into the sprinkler system Even though a nodule can contain many different bacteria they do not necessarily arrive andor thrive simultaneously In order for microbes to attach themselves to the inner wall of the pipe the bacteria must find a desirable site Such sites are defined as containing absorbed nutrients and having a metallurgical feature that the microbes can attach to These features seem to be critical for MIC to occur and consist of irregularities in the pipe surface such as from welded connection pipe seams pre-existing corrosion inclusions etc

After successfully attaching to a location Phase Two starts a lot occurs at this stage (Actually only a fraction of the activity is shown since there can be an immense amount of chemical interaction occurring) Among the microbes by-products are sticky polymers which retain organic and inorganic materials aiding in the creation of the nodule Once the nodule is formed it allows the underlying conditions to become chemically dissimilar to the surrounding surface This is the start of accelerated corrosion which initially leads to crevice corrosion Some of the characteristics of the community at this phase are microbes are located throughout the nodule and the pH level is lowered (acidic) within the crevice but it is still above 4 This lower pH adds to the corrosiveness of the environment as well

as stimulating the growth of certain types of bacteria The increased acidic level is commonly initiated by acid-producing bacteria which produce organic acids as a by-product This acid provides a nutrient source for other bacteria whose by-product results in a buildup of hydrogen protons and an even lower pH level

In the final phas there is continued formation of the nodule over a mature pit Such a pit not only increases in depth but also produces a tunneling characteristic A significant condition is that the pH is less than 4 One of the factors which can contribute to the high acidic level is the weak organic acids discussed in Phase Two These can be converted to a stronger acid by combining with chloride from the water thus producing hydrochloric acid As a result of the high acidity in the pit area live bacteria are present only in the outer portion of the nodule At this point the bacteria could be eliminated and the corrosion would continue as a traditional electrochemical corrosion process Because of a better understanding of the final phase whereby the presence of the bacteria is not required the name was changed from microbiological induced corrosion to microbiological influenced corrosion

How to identify MIC

Experts need to use all three of the following confirmation tests to identify MIC

Chemical-Test directly for pH organic acids and test indirectly (test byproducts) for iron sulfide

Biological-Several methods available The most common are the MIC Field Kit andor microbiological culturing (Requires 28 days or more to produce results)

Metallurgical-Visually identify shiny metal underneath corrosion products

Minimizing MIC

bull Routine inspectionsbull Clean environmentbull Design of the bargebull Barrier Systembull Chemical Treatments Through Green Chemistrybull Maintain the Coating Systembull Other methods

Substrate Resurfacer No F-121

Single component high strength rapid set Portland cement based product for repairing resurfacing and waterproofing masonry structuresThis material will restore structural integrity and prevent water infiltration into concrete and brick structures It is designed for rotary and straight shot spray applications and can be applied at various thicknesses in one pass

Filler Compound No 209

Three component epoxy formulation that is specifically designed to fill voids irregularities and air pockets in concrete No 209 will provide a smooth surface ready for application of protective compounds in 3 hours This material is also available in a fast setting grade that can be topcoated in 1 hour Either formulation is suitable for application over damp or dry concrete Application is performed with a rubber KampR trowel

ACTIVE INFLOW AND WATERSTOP PRODUCTS

Manhole ChimneySeal No F-88

Elastomeric lining composed of fiber-reinforced asphalt-modified urethane Two component chemical resistant seal that can be applied by a gloved hand onto the chimney sections of manholes to prevent water inflow As a high solids elastomer Chimney Seal maintains excellent elasticity and adhesion over a temperature range of -301048722F to 2501048722F while resisting acids alkalies and salts

InstaPlug No F-180

Rapid setting hydraulic water plug that will seal active water leaks and allow continuous rehabilitation work on concrete structures This material will set in 60 ndash 90 seconds and cure completely in

one hour It is also used to fill small voids and for anchoring applications

Hydroactive Polyurethane Grout No F-370

Catalyzed hydrophobic grout that reacts with moisture and expands to 20 times its volume to seal leaks cracks joints and voids It bonds tenaciously to practically any substrate wet or dry it has excellent chemical resistance and it is safe for potable water

SPECIALTY

PenePrime No 500

Two component water-borne epoxy primer that is specially formulated to work in conjunction with other Sauereisen products PenePrime penetrates deep into the concrete substrate to seal porous substrates and reduce off-gassing from concrete This product is manufactured to ensure maximum adhesion of the specified protective coating Application is performed by brush roll or spray

Microbiological Influenced Corrosion

What is MIC

There are biological organisms (microbes) which influence corrosion The primary and to many the only concern is that this influence often results in an extremely accelerated rate of corrosion It affects most alloys such as ductile iron steel (including stainless and galvanized) and copper but it doesnt seem to affect titanium The affect does vary between the different alloys with ductile iron corroding slower than steel There was also a case where MIC caused the water in copper pipe to turn blue

MIC is not caused by a single microbe but is attributed to many different microbes These are often categorized by common characteristics such as by-products (ie sludge producing) or compounds they effect (ie sulfur oxidizing) In a general sense they all fall into one of two groups based upon their oxygen requirements one being aerobic (requires oxygen) such as sulfur oxidizing bacteria and the other being anaerobic (requires little or no oxygen) such as sulfate reducing bacteria

General corrosion affects the entire surface or at least the wetted surface MIC on the other hand is very localized It creates a nodule and a pit beneath the nodule There can be only a few nodules or there can be many Within these nodules microbes rarely work alone but operate as a mixed community of differing types and groups The different microbes perform different functions within the community This interaction allows a community to thrive in environments that are actually hostile to some of its members For example in an aerobic environment anaerobic bacteria are generally inhibited or killed But within a community the aerobic bacteria reside in the outer layer of the nodule consuming the oxygen in the water as it penetrates the nodule Thus the inner portion of the nodule experiences a reduced oxygen level allowing anaerobic bacteria to thrive

Types of microorganism that produce MIC

Acid Producing Bacteria (APBrsquos-Aerobic or Facultative Anaerobic)

Sulfate-reducing Bacteria (SRBrsquos) Iron or Manganese Bacteria Slime Formers

How MIC Works

As already identified MIC operates as an individual nodule covering a pit The development of this process occurs in three phases which are

Attachment of microbes Growth of nodule and initial pit Mature pit and nodule

Phase One Obviously for MIC to occur the microbes must be introduced into the sprinkler system Even though a nodule can contain many different bacteria they do not necessarily arrive andor thrive simultaneously In order for microbes to attach themselves to the inner wall of the pipe the bacteria must find a desirable site Such sites are defined as containing absorbed nutrients and having a metallurgical feature that the microbes can attach to These features seem to be critical for MIC to occur and consist of irregularities in the pipe surface such as from welded connection pipe seams pre-existing corrosion inclusions etc

After successfully attaching to a location Phase Two starts a lot occurs at this stage (Actually only a fraction of the activity is shown since there can be an immense amount of chemical interaction occurring) Among the microbes by-products are sticky polymers which retain organic and inorganic materials aiding in the creation of the nodule Once the nodule is formed it allows the underlying conditions to become chemically dissimilar to the surrounding surface This is the start of accelerated corrosion which initially leads to crevice corrosion Some of the characteristics of the community at this phase are microbes are located throughout the nodule and the pH level is lowered (acidic) within the crevice but it is still above 4 This lower pH adds to the corrosiveness of the environment as well

as stimulating the growth of certain types of bacteria The increased acidic level is commonly initiated by acid-producing bacteria which produce organic acids as a by-product This acid provides a nutrient source for other bacteria whose by-product results in a buildup of hydrogen protons and an even lower pH level

In the final phas there is continued formation of the nodule over a mature pit Such a pit not only increases in depth but also produces a tunneling characteristic A significant condition is that the pH is less than 4 One of the factors which can contribute to the high acidic level is the weak organic acids discussed in Phase Two These can be converted to a stronger acid by combining with chloride from the water thus producing hydrochloric acid As a result of the high acidity in the pit area live bacteria are present only in the outer portion of the nodule At this point the bacteria could be eliminated and the corrosion would continue as a traditional electrochemical corrosion process Because of a better understanding of the final phase whereby the presence of the bacteria is not required the name was changed from microbiological induced corrosion to microbiological influenced corrosion

How to identify MIC

Experts need to use all three of the following confirmation tests to identify MIC

Chemical-Test directly for pH organic acids and test indirectly (test byproducts) for iron sulfide

Biological-Several methods available The most common are the MIC Field Kit andor microbiological culturing (Requires 28 days or more to produce results)

Metallurgical-Visually identify shiny metal underneath corrosion products

Minimizing MIC

bull Routine inspectionsbull Clean environmentbull Design of the bargebull Barrier Systembull Chemical Treatments Through Green Chemistrybull Maintain the Coating Systembull Other methods

one hour It is also used to fill small voids and for anchoring applications

Hydroactive Polyurethane Grout No F-370

Catalyzed hydrophobic grout that reacts with moisture and expands to 20 times its volume to seal leaks cracks joints and voids It bonds tenaciously to practically any substrate wet or dry it has excellent chemical resistance and it is safe for potable water

SPECIALTY

PenePrime No 500

Two component water-borne epoxy primer that is specially formulated to work in conjunction with other Sauereisen products PenePrime penetrates deep into the concrete substrate to seal porous substrates and reduce off-gassing from concrete This product is manufactured to ensure maximum adhesion of the specified protective coating Application is performed by brush roll or spray

Microbiological Influenced Corrosion

What is MIC

There are biological organisms (microbes) which influence corrosion The primary and to many the only concern is that this influence often results in an extremely accelerated rate of corrosion It affects most alloys such as ductile iron steel (including stainless and galvanized) and copper but it doesnt seem to affect titanium The affect does vary between the different alloys with ductile iron corroding slower than steel There was also a case where MIC caused the water in copper pipe to turn blue

MIC is not caused by a single microbe but is attributed to many different microbes These are often categorized by common characteristics such as by-products (ie sludge producing) or compounds they effect (ie sulfur oxidizing) In a general sense they all fall into one of two groups based upon their oxygen requirements one being aerobic (requires oxygen) such as sulfur oxidizing bacteria and the other being anaerobic (requires little or no oxygen) such as sulfate reducing bacteria

General corrosion affects the entire surface or at least the wetted surface MIC on the other hand is very localized It creates a nodule and a pit beneath the nodule There can be only a few nodules or there can be many Within these nodules microbes rarely work alone but operate as a mixed community of differing types and groups The different microbes perform different functions within the community This interaction allows a community to thrive in environments that are actually hostile to some of its members For example in an aerobic environment anaerobic bacteria are generally inhibited or killed But within a community the aerobic bacteria reside in the outer layer of the nodule consuming the oxygen in the water as it penetrates the nodule Thus the inner portion of the nodule experiences a reduced oxygen level allowing anaerobic bacteria to thrive

Types of microorganism that produce MIC

Acid Producing Bacteria (APBrsquos-Aerobic or Facultative Anaerobic)

Sulfate-reducing Bacteria (SRBrsquos) Iron or Manganese Bacteria Slime Formers

How MIC Works

As already identified MIC operates as an individual nodule covering a pit The development of this process occurs in three phases which are

Attachment of microbes Growth of nodule and initial pit Mature pit and nodule

Phase One Obviously for MIC to occur the microbes must be introduced into the sprinkler system Even though a nodule can contain many different bacteria they do not necessarily arrive andor thrive simultaneously In order for microbes to attach themselves to the inner wall of the pipe the bacteria must find a desirable site Such sites are defined as containing absorbed nutrients and having a metallurgical feature that the microbes can attach to These features seem to be critical for MIC to occur and consist of irregularities in the pipe surface such as from welded connection pipe seams pre-existing corrosion inclusions etc

After successfully attaching to a location Phase Two starts a lot occurs at this stage (Actually only a fraction of the activity is shown since there can be an immense amount of chemical interaction occurring) Among the microbes by-products are sticky polymers which retain organic and inorganic materials aiding in the creation of the nodule Once the nodule is formed it allows the underlying conditions to become chemically dissimilar to the surrounding surface This is the start of accelerated corrosion which initially leads to crevice corrosion Some of the characteristics of the community at this phase are microbes are located throughout the nodule and the pH level is lowered (acidic) within the crevice but it is still above 4 This lower pH adds to the corrosiveness of the environment as well

as stimulating the growth of certain types of bacteria The increased acidic level is commonly initiated by acid-producing bacteria which produce organic acids as a by-product This acid provides a nutrient source for other bacteria whose by-product results in a buildup of hydrogen protons and an even lower pH level

In the final phas there is continued formation of the nodule over a mature pit Such a pit not only increases in depth but also produces a tunneling characteristic A significant condition is that the pH is less than 4 One of the factors which can contribute to the high acidic level is the weak organic acids discussed in Phase Two These can be converted to a stronger acid by combining with chloride from the water thus producing hydrochloric acid As a result of the high acidity in the pit area live bacteria are present only in the outer portion of the nodule At this point the bacteria could be eliminated and the corrosion would continue as a traditional electrochemical corrosion process Because of a better understanding of the final phase whereby the presence of the bacteria is not required the name was changed from microbiological induced corrosion to microbiological influenced corrosion

How to identify MIC

Experts need to use all three of the following confirmation tests to identify MIC

Chemical-Test directly for pH organic acids and test indirectly (test byproducts) for iron sulfide

Biological-Several methods available The most common are the MIC Field Kit andor microbiological culturing (Requires 28 days or more to produce results)

Metallurgical-Visually identify shiny metal underneath corrosion products

Minimizing MIC

bull Routine inspectionsbull Clean environmentbull Design of the bargebull Barrier Systembull Chemical Treatments Through Green Chemistrybull Maintain the Coating Systembull Other methods

Microbiological Influenced Corrosion

What is MIC

There are biological organisms (microbes) which influence corrosion The primary and to many the only concern is that this influence often results in an extremely accelerated rate of corrosion It affects most alloys such as ductile iron steel (including stainless and galvanized) and copper but it doesnt seem to affect titanium The affect does vary between the different alloys with ductile iron corroding slower than steel There was also a case where MIC caused the water in copper pipe to turn blue

MIC is not caused by a single microbe but is attributed to many different microbes These are often categorized by common characteristics such as by-products (ie sludge producing) or compounds they effect (ie sulfur oxidizing) In a general sense they all fall into one of two groups based upon their oxygen requirements one being aerobic (requires oxygen) such as sulfur oxidizing bacteria and the other being anaerobic (requires little or no oxygen) such as sulfate reducing bacteria

General corrosion affects the entire surface or at least the wetted surface MIC on the other hand is very localized It creates a nodule and a pit beneath the nodule There can be only a few nodules or there can be many Within these nodules microbes rarely work alone but operate as a mixed community of differing types and groups The different microbes perform different functions within the community This interaction allows a community to thrive in environments that are actually hostile to some of its members For example in an aerobic environment anaerobic bacteria are generally inhibited or killed But within a community the aerobic bacteria reside in the outer layer of the nodule consuming the oxygen in the water as it penetrates the nodule Thus the inner portion of the nodule experiences a reduced oxygen level allowing anaerobic bacteria to thrive

Types of microorganism that produce MIC

Acid Producing Bacteria (APBrsquos-Aerobic or Facultative Anaerobic)

Sulfate-reducing Bacteria (SRBrsquos) Iron or Manganese Bacteria Slime Formers

How MIC Works

As already identified MIC operates as an individual nodule covering a pit The development of this process occurs in three phases which are

Attachment of microbes Growth of nodule and initial pit Mature pit and nodule

Phase One Obviously for MIC to occur the microbes must be introduced into the sprinkler system Even though a nodule can contain many different bacteria they do not necessarily arrive andor thrive simultaneously In order for microbes to attach themselves to the inner wall of the pipe the bacteria must find a desirable site Such sites are defined as containing absorbed nutrients and having a metallurgical feature that the microbes can attach to These features seem to be critical for MIC to occur and consist of irregularities in the pipe surface such as from welded connection pipe seams pre-existing corrosion inclusions etc

After successfully attaching to a location Phase Two starts a lot occurs at this stage (Actually only a fraction of the activity is shown since there can be an immense amount of chemical interaction occurring) Among the microbes by-products are sticky polymers which retain organic and inorganic materials aiding in the creation of the nodule Once the nodule is formed it allows the underlying conditions to become chemically dissimilar to the surrounding surface This is the start of accelerated corrosion which initially leads to crevice corrosion Some of the characteristics of the community at this phase are microbes are located throughout the nodule and the pH level is lowered (acidic) within the crevice but it is still above 4 This lower pH adds to the corrosiveness of the environment as well

as stimulating the growth of certain types of bacteria The increased acidic level is commonly initiated by acid-producing bacteria which produce organic acids as a by-product This acid provides a nutrient source for other bacteria whose by-product results in a buildup of hydrogen protons and an even lower pH level

In the final phas there is continued formation of the nodule over a mature pit Such a pit not only increases in depth but also produces a tunneling characteristic A significant condition is that the pH is less than 4 One of the factors which can contribute to the high acidic level is the weak organic acids discussed in Phase Two These can be converted to a stronger acid by combining with chloride from the water thus producing hydrochloric acid As a result of the high acidity in the pit area live bacteria are present only in the outer portion of the nodule At this point the bacteria could be eliminated and the corrosion would continue as a traditional electrochemical corrosion process Because of a better understanding of the final phase whereby the presence of the bacteria is not required the name was changed from microbiological induced corrosion to microbiological influenced corrosion

How to identify MIC

Experts need to use all three of the following confirmation tests to identify MIC

Chemical-Test directly for pH organic acids and test indirectly (test byproducts) for iron sulfide

Biological-Several methods available The most common are the MIC Field Kit andor microbiological culturing (Requires 28 days or more to produce results)

Metallurgical-Visually identify shiny metal underneath corrosion products

Minimizing MIC

bull Routine inspectionsbull Clean environmentbull Design of the bargebull Barrier Systembull Chemical Treatments Through Green Chemistrybull Maintain the Coating Systembull Other methods

MIC is not caused by a single microbe but is attributed to many different microbes These are often categorized by common characteristics such as by-products (ie sludge producing) or compounds they effect (ie sulfur oxidizing) In a general sense they all fall into one of two groups based upon their oxygen requirements one being aerobic (requires oxygen) such as sulfur oxidizing bacteria and the other being anaerobic (requires little or no oxygen) such as sulfate reducing bacteria

General corrosion affects the entire surface or at least the wetted surface MIC on the other hand is very localized It creates a nodule and a pit beneath the nodule There can be only a few nodules or there can be many Within these nodules microbes rarely work alone but operate as a mixed community of differing types and groups The different microbes perform different functions within the community This interaction allows a community to thrive in environments that are actually hostile to some of its members For example in an aerobic environment anaerobic bacteria are generally inhibited or killed But within a community the aerobic bacteria reside in the outer layer of the nodule consuming the oxygen in the water as it penetrates the nodule Thus the inner portion of the nodule experiences a reduced oxygen level allowing anaerobic bacteria to thrive

Types of microorganism that produce MIC

Acid Producing Bacteria (APBrsquos-Aerobic or Facultative Anaerobic)

Sulfate-reducing Bacteria (SRBrsquos) Iron or Manganese Bacteria Slime Formers

How MIC Works

As already identified MIC operates as an individual nodule covering a pit The development of this process occurs in three phases which are

Attachment of microbes Growth of nodule and initial pit Mature pit and nodule

Phase One Obviously for MIC to occur the microbes must be introduced into the sprinkler system Even though a nodule can contain many different bacteria they do not necessarily arrive andor thrive simultaneously In order for microbes to attach themselves to the inner wall of the pipe the bacteria must find a desirable site Such sites are defined as containing absorbed nutrients and having a metallurgical feature that the microbes can attach to These features seem to be critical for MIC to occur and consist of irregularities in the pipe surface such as from welded connection pipe seams pre-existing corrosion inclusions etc

After successfully attaching to a location Phase Two starts a lot occurs at this stage (Actually only a fraction of the activity is shown since there can be an immense amount of chemical interaction occurring) Among the microbes by-products are sticky polymers which retain organic and inorganic materials aiding in the creation of the nodule Once the nodule is formed it allows the underlying conditions to become chemically dissimilar to the surrounding surface This is the start of accelerated corrosion which initially leads to crevice corrosion Some of the characteristics of the community at this phase are microbes are located throughout the nodule and the pH level is lowered (acidic) within the crevice but it is still above 4 This lower pH adds to the corrosiveness of the environment as well

as stimulating the growth of certain types of bacteria The increased acidic level is commonly initiated by acid-producing bacteria which produce organic acids as a by-product This acid provides a nutrient source for other bacteria whose by-product results in a buildup of hydrogen protons and an even lower pH level

In the final phas there is continued formation of the nodule over a mature pit Such a pit not only increases in depth but also produces a tunneling characteristic A significant condition is that the pH is less than 4 One of the factors which can contribute to the high acidic level is the weak organic acids discussed in Phase Two These can be converted to a stronger acid by combining with chloride from the water thus producing hydrochloric acid As a result of the high acidity in the pit area live bacteria are present only in the outer portion of the nodule At this point the bacteria could be eliminated and the corrosion would continue as a traditional electrochemical corrosion process Because of a better understanding of the final phase whereby the presence of the bacteria is not required the name was changed from microbiological induced corrosion to microbiological influenced corrosion

How to identify MIC

Experts need to use all three of the following confirmation tests to identify MIC

Chemical-Test directly for pH organic acids and test indirectly (test byproducts) for iron sulfide

Biological-Several methods available The most common are the MIC Field Kit andor microbiological culturing (Requires 28 days or more to produce results)

Metallurgical-Visually identify shiny metal underneath corrosion products

Minimizing MIC

bull Routine inspectionsbull Clean environmentbull Design of the bargebull Barrier Systembull Chemical Treatments Through Green Chemistrybull Maintain the Coating Systembull Other methods

How MIC Works

As already identified MIC operates as an individual nodule covering a pit The development of this process occurs in three phases which are

Attachment of microbes Growth of nodule and initial pit Mature pit and nodule

Phase One Obviously for MIC to occur the microbes must be introduced into the sprinkler system Even though a nodule can contain many different bacteria they do not necessarily arrive andor thrive simultaneously In order for microbes to attach themselves to the inner wall of the pipe the bacteria must find a desirable site Such sites are defined as containing absorbed nutrients and having a metallurgical feature that the microbes can attach to These features seem to be critical for MIC to occur and consist of irregularities in the pipe surface such as from welded connection pipe seams pre-existing corrosion inclusions etc

After successfully attaching to a location Phase Two starts a lot occurs at this stage (Actually only a fraction of the activity is shown since there can be an immense amount of chemical interaction occurring) Among the microbes by-products are sticky polymers which retain organic and inorganic materials aiding in the creation of the nodule Once the nodule is formed it allows the underlying conditions to become chemically dissimilar to the surrounding surface This is the start of accelerated corrosion which initially leads to crevice corrosion Some of the characteristics of the community at this phase are microbes are located throughout the nodule and the pH level is lowered (acidic) within the crevice but it is still above 4 This lower pH adds to the corrosiveness of the environment as well

as stimulating the growth of certain types of bacteria The increased acidic level is commonly initiated by acid-producing bacteria which produce organic acids as a by-product This acid provides a nutrient source for other bacteria whose by-product results in a buildup of hydrogen protons and an even lower pH level

In the final phas there is continued formation of the nodule over a mature pit Such a pit not only increases in depth but also produces a tunneling characteristic A significant condition is that the pH is less than 4 One of the factors which can contribute to the high acidic level is the weak organic acids discussed in Phase Two These can be converted to a stronger acid by combining with chloride from the water thus producing hydrochloric acid As a result of the high acidity in the pit area live bacteria are present only in the outer portion of the nodule At this point the bacteria could be eliminated and the corrosion would continue as a traditional electrochemical corrosion process Because of a better understanding of the final phase whereby the presence of the bacteria is not required the name was changed from microbiological induced corrosion to microbiological influenced corrosion

How to identify MIC

Experts need to use all three of the following confirmation tests to identify MIC

Chemical-Test directly for pH organic acids and test indirectly (test byproducts) for iron sulfide

Biological-Several methods available The most common are the MIC Field Kit andor microbiological culturing (Requires 28 days or more to produce results)

Metallurgical-Visually identify shiny metal underneath corrosion products

Minimizing MIC

bull Routine inspectionsbull Clean environmentbull Design of the bargebull Barrier Systembull Chemical Treatments Through Green Chemistrybull Maintain the Coating Systembull Other methods

as stimulating the growth of certain types of bacteria The increased acidic level is commonly initiated by acid-producing bacteria which produce organic acids as a by-product This acid provides a nutrient source for other bacteria whose by-product results in a buildup of hydrogen protons and an even lower pH level

In the final phas there is continued formation of the nodule over a mature pit Such a pit not only increases in depth but also produces a tunneling characteristic A significant condition is that the pH is less than 4 One of the factors which can contribute to the high acidic level is the weak organic acids discussed in Phase Two These can be converted to a stronger acid by combining with chloride from the water thus producing hydrochloric acid As a result of the high acidity in the pit area live bacteria are present only in the outer portion of the nodule At this point the bacteria could be eliminated and the corrosion would continue as a traditional electrochemical corrosion process Because of a better understanding of the final phase whereby the presence of the bacteria is not required the name was changed from microbiological induced corrosion to microbiological influenced corrosion

How to identify MIC

Experts need to use all three of the following confirmation tests to identify MIC

Chemical-Test directly for pH organic acids and test indirectly (test byproducts) for iron sulfide

Biological-Several methods available The most common are the MIC Field Kit andor microbiological culturing (Requires 28 days or more to produce results)

Metallurgical-Visually identify shiny metal underneath corrosion products

Minimizing MIC

bull Routine inspectionsbull Clean environmentbull Design of the bargebull Barrier Systembull Chemical Treatments Through Green Chemistrybull Maintain the Coating Systembull Other methods

Biological-Several methods available The most common are the MIC Field Kit andor microbiological culturing (Requires 28 days or more to produce results)

Metallurgical-Visually identify shiny metal underneath corrosion products

Minimizing MIC

bull Routine inspectionsbull Clean environmentbull Design of the bargebull Barrier Systembull Chemical Treatments Through Green Chemistrybull Maintain the Coating Systembull Other methods