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Pharmaceutical Waste Treatment and Disposal Practices
Solid- liquid waste disposal in herbal companies
PRESENTATION OUTLINES
Introduction Types of Waste Problems Involved in Pharmaceutical
waste Treatment Treatment Methods Case Studies Conclusions
INTRODUCTION
Origin Of Pharmaceutical Waste.
Quantity Generated
ORIGIN OF PHARMACEUTICAL WASTE WATER (PWW)
Spent liquors from fermentation processes (e.g. antibiotics, vitamins)
Chemical waste eg. xenobiotics
Condenser waste from evaporation
Floor and laboratory washing waste
QUANTITIES GENERATED
In Ireland about 43 tons of BOD produced per day from Pharmaceutical Industry.
In USA during 1983, about 3 million tons of hazardous waste produced in which 200,000 tons of sludge produced by pharmaceutical industry only.
In India out of 960 million tons of solid waste, about 2 million tons comes fro herbal and agricultural industry.
Types of Waste
Halogenated/non-halogenated solvents Organic chemical residues from still bottom Sludge & tars Heavy metals Test animal remains Return pharmaceuticals Low-level radioactive waste Contaminated filters, etc.
PROBLEMS INVOLVED IN PHARMACEUTICAL WASTEWATER TREATMENT
Diverse characteristics of PWW. Different medicines produce different type of waste
Variable amount of products Mixing of pharmaceutical waste with other type
of waste Also, it may contain high BOD and highly
variable pH
Treatment Methods
Physical Treatment
Chemical Treatment
Thermal Treatment
Biological Treatment
Physical treatment
1. Reverse osmosis (RO): Based on pressure application Removal of dissolved solids Depends on concentration and pH
Reverse osmosis is a process that industry uses to clean water, whether for industrial process applications or to convert brackish water, to clean up wastewater or to recover salts from industrial processes.
In the reverse osmosis process cellophane-like membranes separate purified water from contaminated water.
RO is when a pressure is applied to the concentrated side of the membrane forcing purified water into the dilute side, the rejected impurities from the concentrated side being washed away in the reject water.
RO can also act as an ultra-filter removing particles such as some micro-organisms that may be too large to pass through the pores of the membrane
Common membrane materials include polyamide thin film composites (TFC), cellulose acetate (CA) and cellulose triacetate (CTA) with the membrane material being spiral wound around a tube, or hollow fibres bundled together
2. Dialysis: Based on the chemical activity of the solute Recovery of specific material from aqueous
solution depends on the molecular weigh and dialysis
coefficient
Electrodialysis:
Based on application of an electric field Used to separate ionized species Operates over a wide range of pH
Electrodialysis Membrane System works to achieve separation on the ionic components of the water through the use of semi permeable membranes.
The membranes are alternately stacked together and each of it is either anionic or cationic charged so that the cation exchange membrane will attract the anions leaving only cations to pass through and vice versa for anion membranes.
The principal behind the operation relies on the use of electrical driving force whereby two different electrodes will cause electric current to pass through the solution and thus creating freshwater at the receiving end.
This technique can be applied to remove ions from water. Particles that do not carry an electrical charge are not removed.
Cation-selective membranes consist of sulphonated polystyrene, while anion-selective membranes consist of polystyrene with quaternary ammonia.
Sometimes pre-treatment is necessary before the electro dialysis can take place. Suspended solids with a diameter that exceeds 10 µm need to be removed, or else they will plug the membrane pores.
There are also substances that are able to neutralize a membrane, such as large organic anions, colloids, iron oxides and manganese oxide. These disturb the selective effect of the membrane.
Evaporation/Redistillation
Based on heat energy Recovery of solvents Produces high quality effluent High cost
Granular Activated Carbon Adsorption:
Used for removal of organic contaminants (COD)
Survey showed that 1 out of 25 pharmaceutical plants use this method to treat their wastewater,
COD test - nearly all organic compounds can be fully oxidized to carbon dioxide with a strong oxidizing agent under acidic conditions
Physical treatment…
Filtration:
Used to remove particulate contaminants Colloidal suspensions of fine solids may be
removed by filtration through fine physical barriers distinguished from coarser screens or sieves by the ability to remove particles smaller than the openings through which the water passes.
Sedimentation:
Suspended particles are allowed to settle and supernatant removed.
Solids and non-polar liquids may be removed from wastewater by gravity when density differences are sufficient to overcome dispersion by turbulence.
Gravity separation of solids is the primary treatment of sewage, where the unit process is called "primary settling tanks" or "primary sedimentation tanks".
It is also widely used for the treatment of other wastewaters. Solids that are heavier than water will accumulate at the bottom of quiescent settling basins.
Flocculation:
Gathering of fine particles as flocculates which allows them to settle.
is a process wherein colloids come out of suspension in the form of floc or flake; either spontaneously or due to the addition of a clarifying agent.
The action differs from precipitation in that, prior to flocculation, colloids are merely suspended in a liquid and not actually dissolved in a solution
In the flocculated system, there is no formation of a cake, since all the flocs are in the suspension.
Difference in relative volatility between the organic chemicals and water are used to achieve a separation
Used for recovery of solvents (1 out of 4 pharmaceutical plants and Wastewater treatment 17 out of 91 pharmaceutical plants)
Steam stripping, also known as steam distillation, is an economic method of cleaning up plant wastewater streams.
It is a multistage continuous distillation process where steam is used as a stripping gas to remove hydrocarbons from dischargeable waste waters;
Stream Strippig :
Chemical Treatment Ion-exchange:
Reversible interchange of ions between a solid and a liquid phase
Used for the removal of trace metals, fluorides, nitrates, and manganese
Ion exchange is an exchange of ions between two electrolytes or between an electrolyte solution and a complex.
In most cases the term is used to denote the processes of purification, separation, and decontamination of aqueous and other ion-containing solutions with solid polymeric or mineralic 'ion exchangers'.
Neutralization:
A process utilised to prevent excessively acidic or alkaline wastes discharge
1 out of 2 pharmaceutical plants use neutralization to treat their wastewater
Reduction: Treatment with sulphur dioxide to reduce the oxidants to
less noxious materials
Precipitin: Separation of solid from aqueous waste chemically
Calcination: Heating of waste to a high temperature to oxidize
organic matter
Thermal Treatment
Incineration: Controlled heating processes to covert a waste to less
bulky, less toxic or less noxious Incineration usually involves the combustion of
unprepared (raw or residual) To allow the combustion to take place a sufficient quantity
of oxygen is required to fully oxidize the fuel. Typically, incineration plant combustion (flame) temperatures are in excess of 850ºC and the waste is converted into carbon dioxide and water.
Any non-combustible materials (e.g. metals, glass) remain as a solid, known as Bottom Ash, that contains a small amount of residual carbon.
Pyrolysis:
Thermal decomposition of waste at high temperature in the absence of oxygen
Pyrolysis is the thermal degradation of a substance in the absence of oxygen.
This process requires an external heat source to maintain the temperature required. Typically, relatively low temperatures of between 300ºC to 850ºC are used during pyrolysis of materials such as MSW.
The products produced from pyrolysing materials are a solid residue and a synthetic gas (syngas).
The solid residue (sometimes described as a char) is a combination of non-combustible materials and carbon.
The syngas is a mixture of gases (combustible constituents include carbon monoxide, hydrogen, methane and a broad range of other VOCs).
A proportion of these can be condensed to produce oils, waxes and tars.
The syngas typically has a net calorific value (NCV) of between 10 and 20 MJ/Nm3. If required, the condensable fraction can be collected by cooling the syngas, potentially for use as a liquid fuel
Biological Treatment Used to remove biodegradable organic matter Microorganisms converts organics into:
CO2 and H2O (aerobic) CO2, CH4, and H2O (anaerobic)
1 out of 3 pharmaceutical plants use biological processes
Biological Processes Activated sludge:
process in which microorganisms are continuously circulated and contacted with organic waste in the presence of oxygen
Sludge withdrawn from the secondary clarifier in the activated sludge process, consisting of micro-organisms, non-living organic matter, and inorganic materials.
an activated sludge process includes: An aeration tank where air (or oxygen) is injected and
thoroughly mixed into the wastewater. A settling tank (usually referred to as a clarifier or
"settler") to allow the waste sludge to settle. Part of the waste sludge is recycled to the aeration tank and the remaining waste sludge is removed for further treatment and ultimate disposal
Activated Sludge Process
•A common method of disposing of pollutants in wastewaters. •In the process, large quantities of air are bubbled through wastewaters that contain dissolved organic substances in open aeration tanks. Bacteria and other types of microorganisms present in the system need oxygen to live, grown, and multiply in order to consume the dissolved organic "food" or pollutants in the waste. •After several hours in a large holding tank, the water is separated from the sludge of bacteria and discharged from the system. •Most of the activated sludge is returned to the treatment process, while the remainder is disposed of by one of several acceptable methods.
Aerated lagoons:
a basin in which organic waste stabilised by a dispersed biological growth in the presence of oxygen
promotes the biological oxidation of waste waters.
Types of aerated lagoons or basins
Suspension mixed lagoons, where there is less energy provided by the aeration equipment to keep the sludge in suspension.
Facultative lagoons, where there is insufficient energy provided by the aeration equipment to keep the sludge in suspension and solids settle to the lagoon floor. The biodegradable solids in the settled sludge then degrade anaerobically
large shallow basins store wastewater and purify under natural conditions in the presence of algae
Waste or Wastewater Stabilization Ponds (WSPs) are large, man-made water bodies in which blackwater, greywater or faecal sludge are treated by natural occurring processes and the influence of solar light, wind, microorganisms and algae.
The ponds can be used individually, or linked in a series for improved treatment. There are three types of ponds, (1) anaerobic, (2) facultative and (3) aerobic (maturation), each with different treatment and design characteristics.
large surface areas and expert design are required. The effluent still contains nutrients (e.g. N and P) and is therefore
appropriate for the reuse in agriculture , but not for direct recharge in surface waters.
Waste stabilisation ponds (Polishing ponds):
Anaerobic digestion
Anaerobic digestion is a collection of processes by which microorganisms break down biodegradable material in the absence of oxygen
Closed tanks operated in the absence of oxygen In this method large fraction of organic matter is broken
down in to carbon dioxide and methane and is accomplished in the absence of oxygen.
About half of the material is then converted to gases while the remainder is dried and becomes residual soil-like matter
Trickling filters Artificial beds of rocks or other porous media through which
aqueous organic waste percolated and brought into contact with biological growth and oxygen
A trickling filter consists of a bed of rocks, gravel, slag, peat moss, or plastic media over which wastewater flows downward and contacts a layer (or film) of microbial slime covering the bed media.
Aerobic conditions are maintained by forced air flowing through the bed or by natural convection of air.
The process involves adsorption of organic compounds in the wastewater by the microbial slime layer, diffusion of air into the slime layer to provide the oxygen required for the biochemical oxidation of the organic compounds.
The end products include carbon dioxide gas, water and other products of the oxidation
As the slime layer thickens, it becomes difficult for the air to penetrate the layer and an inner anaerobic layer is formed.
The treatment of sewage or other wastewater with trickling filters is among the oldest and most well characterized treatment technologies.
The fundamental components of a complete trickling filter system are:
A bed of filter medium upon which a layer of microbial slime is promoted and developed.
An enclosure or a container which houses the bed of filter medium
A system for distributing the flow of wastewater over the filter medium.
Any system removing and disposing any sludge from the treated effluent
Ranges of values being used in pharmaceutical wastewater treatment by trickling filters
Parameter Range Units
Flow Rate 0.03 - 2.18 MGD
Hydraulic Loading Rate 2.0 - 5.0 gpm/ft2
Depth of Medium 6 - 72 inches
ANAEROBIC TREATMENT
Anaerobic treatment of pharmaceutical waste is common in different countries because of
lack of biodegradability toxic and malodorous nature of pharmaceutical waste
Commonly Used Anaerobic Systems
Up flow filters Membrane reactors Continuously-stirred reactors Fluidized bed reactors
The anaerobic filter is ideally suited for the treatment of soluble wastes.
No effluent or solids recycle is required with the anaerobic filter because biological solids remain in the filter and are not lost with the effluent.
The accumulation of high concentrations active solids in the filter permits the treatment of dilute wastes.
Very low volumes of sludge produce.
Effluent is essentially free of SS.
Anaerobic filter giving 70 – 80%. COD removal efficiency and 94% BOD5 removal efficiency
It gives 33% better performance as compared to aerobic extended aeration system
Very low volumes of sludge produce
Remove colour with higher efficiency
Waste Disposal
Factors require consideration in the management/disposal of solid pharmaceutical waste Potential hazardous nature of the waste
material
Relatively large volume of material that must be safely and efficiently handled, transported and/or disposed of
Effect of the disposal method on the public and environment
Social factors
Technical feasibility of the construction and operation of the installation
Environmental control
The social importance of other interests in the exploitation and utilisation of the area
Economics of construction and operation of the installation
Steps for the disposal of solid pharmaceutical waste
Segregation
Volume reduction
Incineration
Ultimate disposal
Treatment or Disposal There is not much treatment of solid
pharmaceutical waste. Most of the time solid waste is disposed of.
Separation and reprocessing of some of the solid waste also done for recycling purpose.
Incineration and landfilling of pharmaceutical solid waste is most common
Methods of Waste Disposal
Landfills Incineration Source reduction Composting Recycling
LANDFILLS• Landfills are physical facilities used for the disposal of
residual solid wastes in the surface soils of the earth
• US. EPA defines landfill as a system designed and constructed to contain discarded waste so as to minimize releases of contaminants to the environment
Solid pharmaceutical waste usually incinerated but in some places (e.g. California) most of the solid PW is landfilled
Landfill disposal: Common land filling methods are
Mixing with soil Shallow burial Combination of these
Deep-well disposal Material pumped into subsurface rock separated from
other groundwater supplies by impermeable rock or clay. (In USA more than 100 wells are used for disposal)
Land burial disposal Disposal accomplished by either near-surface or deep
burial In near-surface burial material could be disposed directly
into the ground or is disposed in stainless steel tanks or concrete lined pits beneath the ground. At the present time, only near surface burial is used for disposal of pharmaceutical wastes
Ocean dumping and detonation are some of expensive waste disposal methods
• Detonation is a processes of exploding a quantity of waste with sudden violence Thermal Shock Mechanical Shock Electrostatic charge
This method mainly used for flammable and volatile waste materials
Sanitary Landfill Layer of compacted trash covered with a layer of earth once a day and
a thicker layer when the site is full
Require impermeable barriers to stop escape of leachates: can cause problem by overflow
Gases produced by decomposing garbage needs venting Avoid:
Swampy area/ Flood plains /coastal areas Fractures or porous rocks High water table
Prefer: Clay layers Heads of gullies
Deep-well Disposal
Incineration
combustion of solid waste Solves space problem but:
produces toxic gases like Cl, HCl, HCN, SO2
High temp furnaces break down hazardous compounds but are expensive
Heat generated can be can be recovered
MAJOR TYPES OF INCINERATORS
Grate Type of IncineratorIt is a low temperature incinerator. It is useful for volume
reduction of bulky waste.
Hearth-Type IncineratorMost solid hazardous waste is burned in hearth-type
systems of which there are several basic types: The rotary kiln A "controlled air" or "two chamber fixed hearth" system The multiple hearth incinerator The monohearth (seldom used)
Fludized-Bed IncineratorLiquids, sludges as well as uniformly sized solids can be
incinerated in it
In USA hearth-type systems are common Following types of incinerator are in operation
Rotary Kiln incinerators accounts for 75% Two-chamber, fixed-hearth 15% Multiple-hearth and fluidised bed 10%
Advantages: on average, reduces the volume of solid waste by 80%
Modern high-temperature (up to 3000O F) incineration can decompose many harmful compounds into less hazardous substances
The combustion heat energy can be employed in a “waste-to-energy” facility to generate steam for space heating or electrical energy production (see slide
Disadvantages: incineration solid residue may contain highly concentrated toxins
Requires separation of noncombustible waste, increasing costs
Typically releases a variety of pollutants to the air (e.g., chlorine gas, acidic vapors, toxic metals, carbon dioxide)
Even the high-temperature incinerators can’t destroy toxic elements (e.g., mercury, arsenic)
The high-temperature incinerators are very expensive to operate (~ $2000 per ton of waste), although the less effective low-temperature incinerators are more cost competitive (~ $75 per ton of waste)
Ocean Dumping methods – direct dumping or shipboard incineration
followed by dumping of ash Contributes to ocean pollution Can wash back on beaches, and can cause death of
marine mammals Preferred method: incineration in open sea Ocean Dumping Ban Act, 1988: bans dumping of
sewage sludge and industrial waste Dredge spoils still dumped in oceans, can cause
habitat destruction and export of fluvial pollutants
Source Reduction Most fundamental method of reducing waste is to
prevent it from being produced Reduce and reuse
Saves natural resources. Reduces waste toxicity Reduces costs
Packaging reduction – involves the elimination of unnecessary packaging, the design of packaging that requires less material and the design of manufacturing processes that necessitate less packaging for the products
Composting Harnessing natural decomposition to transform
organic material into compost Composting is the biological decomposition of
organic waste such as food or plant material by bacteria, fungi, worms and other organisms under controlled aerobic (occurring in the presence of oxygen) conditions.
The end result of composting is an accumulation of partially decayed organic matter called humus. Composting with worms, also known as vermiculture, results in nutrient-loaded worm castings
RECYCLING SOLID WASTE
Recycling is a process to convert waste materials into new products to prevent waste of potentially useful materials, reduce the consumption of fresh raw materials, reduce energy usage, reduce air pollution (from incineration) and water pollution (from landfilling) by reducing the need for "conventional" waste disposal and lower greenhouse gas emissions as compared to plastic production.
Recycling is a key component of modern waste reduction and is the third component of the "Reduce, Reuse and Recycle" waste hierarchy.
Benefits of Recycling Reduces the amount of waste sent to landfills and
incinerators; Conserves natural resources such as timber, water, and
minerals; Prevents pollution by reducing the need to collect new raw
materials; Saves energy; Reduces greenhouse gas emissions that contribute to
global climate change; Helps sustain the environment for future generations;
Different Steps in Recycling
Collection and Processing Manufacturing Purchasing new drugs from recycled materials
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