Cover

Advanced Biological ProcessSTM-Aerotor™

© WesTech Engineering, Inc. 2011

WESTECHProcess Equipment. Process Driven.

Tel: 801.265.1000Fax: 801.265.1080www.westech-inc.cominfo@westech-inc.com P.O. Box 65068, Salt Lake City, Utah84165-0068

Represented by:

Our employee-owners have a deep commitment to

the success of WesTech. As the sole stockholders

in WesTech, employee-owners directly benefit from

successful projects and happy customers.

How Does Working with an Employee-Owned Company Benefit You?Employee ownership creates an environment in

which people want to contribute to this common

goal. You will notice extra attention to customers

and pride in our equipment at WesTech.

CALL TODAY TO DISCUSS YOUR PROCESS NEEDS.

From sea level to 17,000 ft elevation the STM-Aerotor has

proven to be a reliable and simple treatment process that delivers a

great quality effluent while saving money and energy.

Other WesTech Process Equipment Complete Line of Headworks Complete Line of Tertiary Filters OxyStream™ Advanced Oxidation Ditch Process Landox™ Oxidation Ditch

Landy™ Slow Speed Surface Aerators ClearLogic™ MBR System HydroDoc™ Rotary Distributor BioDoc® Rotary Distributor

Stable Process Performance Exceptional process stability and flexibility is ensured, even under high loadings, by combining the activated sludge and fixed film processes. Even the strictest effluent standards can be met consistently.

Solid and Simple ConstructionThe system provides long-life polypropylene media, a simple low-maintenance drive train, and low-friction support bearings for extended life.

Lower Capital CostTank volume is reduced up to 40% versus conventional activated sludge. No mixers or blowers are required.

Lower Energy UsagePower consumption is less than 50% of a conventional activated sludge system, and only 40% of a comparable sequencing batch reactor.

Advanced Biological Nutrient RemovalThe STM-Aerotor can provide consistent nitrification/denitrification, as well as biological phosphorus removal.

No Noise or Odor ProblemsSimple slow-speed mechanism reduces operating noise. The STM-Aerotor process eliminates aerosols and minimizes odors.

Improved Sludge QualityThe system provides better sludge settling characteristics (lower sludge volume index), better dewatering, and smaller volumes of waste sludge.

Many ApplicationsThe STM-Aerotor is applicable to a wide variety of processes and industries.

The STM- Aerotor™ Delivers...

Integrated Fixed Film and Activated Sludge

Activated SludgeThe STM-Aerotor™ captures atmospheric air with each rotation, draws it down into the mixed liquor, and slowly releases the compressed air as coarse bubble aeration. The amount of aeration can be controlled using a variable speed drive to speed up or slow down the rotor based on the actual oxygen demand.

The aeration of the system is achieved without the use of blowers, aeration piping, or diffusers. During the rotation, additional cascade aeration elevates the dissolved oxy-gen in the upper layer of the basin. The slow rotation of the STM-Aerotor, intense air release, and the addition of aperipheral mixing paddle combine to ensure a thoroughly mixed system.

Fixed FilmIn addition to ensuring effective aeration, the STM-Aerotor also provides a large surface area for fixed film growth. The interior and exterior of the special polypropylene discs provide the perfect environment for a variety of attached growth organisms. The fixed film component increases the “effective” sludge age and improves the sludge set-tling characteristics. The fixed film will react quickly to an increased food source, or shock load, to eliminate discharge violations during peak or diurnal fluctuations.

Biological Nutrient Removal The unique STM-Aerotor design allows the process tank to develop both anoxic and/or anaerobic zones within the same basin. The process control system can typically achieve total nitrogen below 10mg/l and total phosphorous below 2 mg/l. For enhanced biological nutrient removal, the STM-Aerotor system can be combined with additional biological selector zones in separate basins to achieve total nitrogen below 3 mg/l and total phosphorus below 1 mg/l.

Mixing Paddle

Cascade Aeration

Coarse Bubble Aeration

1.0

0.2

0.0mg/L O2

Waste Activated Sludge ( WAS)

Effluent

Influent

Figure 1Return Activatd Sludge (RAS)

MLSS 3000-8000 mg/L

Anaerobic

Anoxic

Small Installations and Package Plants

Ideal for plants with close neighbors, the STM-Aerotor plant will minimize both noise and odors. Biological treatment is achieved without noisy blowers, while reactive fixed film organisms help eliminate nuisance gases. In addition, new developments usually reserve minimal space for wastewater treatment. The compact design allows the STM-Aerotor plant to fit into tight sites. The low HP drives allow the new plant to operate on single-phase power, eliminating the need for transformers or new power feed. Most importantly, the STM-Aerotor system produces a high quality effluent with complete nitrification, along with single digit biochemical oxygen demand (BOD) and total suspended solids (TSS) values.

WesTech can design and supply complete package plants to meet the strictest effluent requirements. These package plants can include flow equalization, digesters, disinfection, and tertiary filtration. These compact systems minimize footprint and operator attention. Package plants can range from the most basic control scheme to fully automated systems.

The STM-Aerotor’s ability to accommodate seasonal fluctuations in flow rate makes it ideal for destination resorts, educational institutions correctional facilities and campgrounds. The multiple trains of an STM-Aerotor system can easily be taken off-line or placed on-line based upon demand. The STM-Aerotor wheels are controlled with variable frequency drives (VFD) and dissolved oxygen (DO) probes to optimize the process while minimizing operator attention.

Mechanical Simplicity

Low HP Drive Unit - The simple drive unit is easily accessible and is controlled by a VFD. Drive lubrication is the only routine maintenance item in the process.

Drive Chain - The drive chain is constructed of hardened steel components.

Steel Center Shaft - The center shaft provides connecting points for the STM-Aerotor frame assembly.

Steel Structural Frame - The steel structural frame is designed to transfer the loads from the media to the supports at the wall.

Support Bearings - The specially designed bearing assemblies require no maintenance. The bearings are backed by a ten-year guarantee.

Mixing Paddle - To allow the system to be deep enough to develop zones that are oxygen limited, a mixing paddle is added to ensure mixing.

Com

pact

Des

ign

Pack

age

Plan

tsFl

exib

le O

pera

tion

STM Media - The special STM media discs maximize the surface area for the fixed film, while optimizing the captured air volume and release depth for efficient aeration.

Integrated Fixed Film and Activated Sludge

Activated SludgeThe STM-Aerotor™ captures atmospheric air with each rotation, draws it down into the mixed liquor, and slowly releases the compressed air as coarse bubble aeration. The amount of aeration can be controlled using a variable speed drive to speed up or slow down the rotor based on the actual oxygen demand.

The aeration of the system is achieved without the use of blowers, aeration piping, or diffusers. During the rotation, additional cascade aeration elevates the dissolved oxy-gen in the upper layer of the basin. The slow rotation of the STM-Aerotor, intense air release, and the addition of aperipheral mixing paddle combine to ensure a thoroughly mixed system.

Fixed FilmIn addition to ensuring effective aeration, the STM-Aerotor also provides a large surface area for fixed film growth. The interior and exterior of the special polypropylene discs provide the perfect environment for a variety of attached growth organisms. The fixed film component increases the “effective” sludge age and improves the sludge set-tling characteristics. The fixed film will react quickly to an increased food source, or shock load, to eliminate discharge violations during peak or diurnal fluctuations.

Biological Nutrient Removal The unique STM-Aerotor design allows the process tank to develop both anoxic and/or anaerobic zones within the same basin. The process control system can typically achieve total nitrogen below 10mg/l and total phosphorous below 2 mg/l. For enhanced biological nutrient removal, the STM-Aerotor system can be combined with additional biological selector zones in separate basins to achieve total nitrogen below 3 mg/l and total phosphorus below 1 mg/l.

Mixing Paddle

Cascade Aeration

Coarse Bubble Aeration

1.0

0.2

0.0mg/L O2

Waste Activated Sludge ( WAS)

Effluent

Influent

Figure 1Return Activatd Sludge (RAS)

MLSS 3000-8000 mg/L

Anaerobic

Anoxic

Small Installations and Package Plants

Ideal for plants with close neighbors, the STM-Aerotor plant will minimize both noise and odors. Biological treatment is achieved without noisy blowers, while reactive fixed film organisms help eliminate nuisance gases. In addition, new developments usually reserve minimal space for wastewater treatment. The compact design allows the STM-Aerotor plant to fit into tight sites. The low HP drives allow the new plant to operate on single-phase power, eliminating the need for transformers or new power feed. Most importantly, the STM-Aerotor system produces a high quality effluent with complete nitrification, along with single digit biochemical oxygen demand (BOD) and total suspended solids (TSS) values.

WesTech can design and supply complete package plants to meet the strictest effluent requirements. These package plants can include flow equalization, digesters, disinfection, and tertiary filtration. These compact systems minimize footprint and operator attention. Package plants can range from the most basic control scheme to fully automated systems.

The STM-Aerotor’s ability to accommodate seasonal fluctuations in flow rate makes it ideal for destination resorts, educational institutions correctional facilities and campgrounds. The multiple trains of an STM-Aerotor system can easily be taken off-line or placed on-line based upon demand. The STM-Aerotor wheels are controlled with variable frequency drives (VFD) and dissolved oxygen (DO) probes to optimize the process while minimizing operator attention.

Mechanical Simplicity

Low HP Drive Unit - The simple drive unit is easily accessible and is controlled by a VFD. Drive lubrication is the only routine maintenance item in the process.

Drive Chain - The drive chain is constructed of hardened steel components.

Steel Center Shaft - The center shaft provides connecting points for the STM-Aerotor frame assembly.

Steel Structural Frame - The steel structural frame is designed to transfer the loads from the media to the supports at the wall.

Support Bearings - The specially designed bearing assemblies require no maintenance. The bearings are backed by a ten-year guarantee.

Mixing Paddle - To allow the system to be deep enough to develop zones that are oxygen limited, a mixing paddle is added to ensure mixing.

Com

pact

Des

ign

Pack

age

Plan

tsFl

exib

le O

pera

tion

STM Media - The special STM media discs maximize the surface area for the fixed film, while optimizing the captured air volume and release depth for efficient aeration.

Integrated Fixed Film and Activated Sludge

Activated SludgeThe STM-Aerotor™ captures atmospheric air with each rotation, draws it down into the mixed liquor, and slowly releases the compressed air as coarse bubble aeration. The amount of aeration can be controlled using a variable speed drive to speed up or slow down the rotor based on the actual oxygen demand.

The aeration of the system is achieved without the use of blowers, aeration piping, or diffusers. During the rotation, additional cascade aeration elevates the dissolved oxy-gen in the upper layer of the basin. The slow rotation of the STM-Aerotor, intense air release, and the addition of aperipheral mixing paddle combine to ensure a thoroughly mixed system.

Fixed FilmIn addition to ensuring effective aeration, the STM-Aerotor also provides a large surface area for fixed film growth. The interior and exterior of the special polypropylene discs provide the perfect environment for a variety of attached growth organisms. The fixed film component increases the “effective” sludge age and improves the sludge set-tling characteristics. The fixed film will react quickly to an increased food source, or shock load, to eliminate discharge violations during peak or diurnal fluctuations.

Biological Nutrient Removal The unique STM-Aerotor design allows the process tank to develop both anoxic and/or anaerobic zones within the same basin. The process control system can typically achieve total nitrogen below 10mg/l and total phosphorous below 2 mg/l. For enhanced biological nutrient removal, the STM-Aerotor system can be combined with additional biological selector zones in separate basins to achieve total nitrogen below 3 mg/l and total phosphorus below 1 mg/l.

Mixing Paddle

Cascade Aeration

Coarse Bubble Aeration

1.0

0.2

0.0mg/L O2

Waste Activated Sludge ( WAS)

Effluent

Influent

Figure 1Return Activatd Sludge (RAS)

MLSS 3000-8000 mg/L

Anaerobic

Anoxic

Small Installations and Package Plants

Ideal for plants with close neighbors, the STM-Aerotor plant will minimize both noise and odors. Biological treatment is achieved without noisy blowers, while reactive fixed film organisms help eliminate nuisance gases. In addition, new developments usually reserve minimal space for wastewater treatment. The compact design allows the STM-Aerotor plant to fit into tight sites. The low HP drives allow the new plant to operate on single-phase power, eliminating the need for transformers or new power feed. Most importantly, the STM-Aerotor system produces a high quality effluent with complete nitrification, along with single digit biochemical oxygen demand (BOD) and total suspended solids (TSS) values.

WesTech can design and supply complete package plants to meet the strictest effluent requirements. These package plants can include flow equalization, digesters, disinfection, and tertiary filtration. These compact systems minimize footprint and operator attention. Package plants can range from the most basic control scheme to fully automated systems.

The STM-Aerotor’s ability to accommodate seasonal fluctuations in flow rate makes it ideal for destination resorts, educational institutions correctional facilities and campgrounds. The multiple trains of an STM-Aerotor system can easily be taken off-line or placed on-line based upon demand. The STM-Aerotor wheels are controlled with variable frequency drives (VFD) and dissolved oxygen (DO) probes to optimize the process while minimizing operator attention.

Mechanical Simplicity

Low HP Drive Unit - The simple drive unit is easily accessible and is controlled by a VFD. Drive lubrication is the only routine maintenance item in the process.

Drive Chain - The drive chain is constructed of hardened steel components.

Steel Center Shaft - The center shaft provides connecting points for the STM-Aerotor frame assembly.

Steel Structural Frame - The steel structural frame is designed to transfer the loads from the media to the supports at the wall.

Support Bearings - The specially designed bearing assemblies require no maintenance. The bearings are backed by a ten-year guarantee.

Mixing Paddle - To allow the system to be deep enough to develop zones that are oxygen limited, a mixing paddle is added to ensure mixing.

Com

pact

Des

ign

Pack

age

Plan

tsFl

exib

le O

pera

tion

STM Media - The special STM media discs maximize the surface area for the fixed film, while optimizing the captured air volume and release depth for efficient aeration.

Cover

Advanced Biological ProcessSTM-Aerotor™

© WesTech Engineering, Inc. 2011

WESTECHProcess Equipment. Process Driven.

Tel: 801.265.1000Fax: 801.265.1080www.westech-inc.cominfo@westech-inc.com P.O. Box 65068, Salt Lake City, Utah84165-0068

Represented by:

Our employee-owners have a deep commitment to

the success of WesTech. As the sole stockholders

in WesTech, employee-owners directly benefit from

successful projects and happy customers.

How Does Working with an Employee-Owned Company Benefit You?Employee ownership creates an environment in

which people want to contribute to this common

goal. You will notice extra attention to customers

and pride in our equipment at WesTech.

CALL TODAY TO DISCUSS YOUR PROCESS NEEDS.

From sea level to 17,000 ft elevation the STM-Aerotor has

proven to be a reliable and simple treatment process that delivers a

great quality effluent while saving money and energy.

Other WesTech Process Equipment Complete Line of Headworks Complete Line of Tertiary Filters OxyStream™ Advanced Oxidation Ditch Process Landox™ Oxidation Ditch

Landy™ Slow Speed Surface Aerators ClearLogic™ MBR System HydroDoc™ Rotary Distributor BioDoc® Rotary Distributor

Stable Process Performance Exceptional process stability and flexibility is ensured, even under high loadings, by combining the activated sludge and fixed film processes. Even the strictest effluent standards can be met consistently.

Solid and Simple ConstructionThe system provides long-life polypropylene media, a simple low-maintenance drive train, and low-friction support bearings for extended life.

Lower Capital CostTank volume is reduced up to 40% versus conventional activated sludge. No mixers or blowers are required.

Lower Energy UsagePower consumption is less than 50% of a conventional activated sludge system, and only 40% of a comparable sequencing batch reactor.

Advanced Biological Nutrient RemovalThe STM-Aerotor can provide consistent nitrification/denitrification, as well as biological phosphorus removal.

No Noise or Odor ProblemsSimple slow-speed mechanism reduces operating noise. The STM-Aerotor process eliminates aerosols and minimizes odors.

Improved Sludge QualityThe system provides better sludge settling characteristics (lower sludge volume index), better dewatering, and smaller volumes of waste sludge.

Many ApplicationsThe STM-Aerotor is applicable to a wide variety of processes and industries.

The STM- Aerotor™ Delivers...

Cover

Advanced Biological ProcessSTM-Aerotor™

© WesTech Engineering, Inc. 2011

WESTECHProcess Equipment. Process Driven.

Tel: 801.265.1000Fax: 801.265.1080www.westech-inc.cominfo@westech-inc.com P.O. Box 65068, Salt Lake City, Utah84165-0068

Represented by:

Our employee-owners have a deep commitment to

the success of WesTech. As the sole stockholders

in WesTech, employee-owners directly benefit from

successful projects and happy customers.

How Does Working with an Employee-Owned Company Benefit You?Employee ownership creates an environment in

which people want to contribute to this common

goal. You will notice extra attention to customers

and pride in our equipment at WesTech.

CALL TODAY TO DISCUSS YOUR PROCESS NEEDS.

From sea level to 17,000 ft elevation the STM-Aerotor has

proven to be a reliable and simple treatment process that delivers a

great quality effluent while saving money and energy.

Other WesTech Process Equipment Complete Line of Headworks Complete Line of Tertiary Filters OxyStream™ Advanced Oxidation Ditch Process Landox™ Oxidation Ditch

Landy™ Slow Speed Surface Aerators ClearLogic™ MBR System HydroDoc™ Rotary Distributor BioDoc® Rotary Distributor

Stable Process Performance Exceptional process stability and flexibility is ensured, even under high loadings, by combining the activated sludge and fixed film processes. Even the strictest effluent standards can be met consistently.

Solid and Simple ConstructionThe system provides long-life polypropylene media, a simple low-maintenance drive train, and low-friction support bearings for extended life.

Lower Capital CostTank volume is reduced up to 40% versus conventional activated sludge. No mixers or blowers are required.

Lower Energy UsagePower consumption is less than 50% of a conventional activated sludge system, and only 40% of a comparable sequencing batch reactor.

Advanced Biological Nutrient RemovalThe STM-Aerotor can provide consistent nitrification/denitrification, as well as biological phosphorus removal.

No Noise or Odor ProblemsSimple slow-speed mechanism reduces operating noise. The STM-Aerotor process eliminates aerosols and minimizes odors.

Improved Sludge QualityThe system provides better sludge settling characteristics (lower sludge volume index), better dewatering, and smaller volumes of waste sludge.

Many ApplicationsThe STM-Aerotor is applicable to a wide variety of processes and industries.

The STM- Aerotor™ Delivers...