This document provides information about the pesticide industry. It discusses the manufacturing process which involves raw materials, reactors, fractionation, drying, and packaging. It also discusses the formulation process which involves mixing active ingredients and inert materials. The document notes that pesticide production generates wastewater from processes, washing, and scrubbers. It provides effluent standards for pesticide industry wastewater set by the Central Pollution Control Board. The pollution effects on streams are also briefly mentioned.
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Pesticide Industry
1. PESTICIDE INDUSTRY Page 1
VEERMATA JIJAMATA TECHNOLOGICAL INSTITUTE,
MATUNGA, MUMBAI.
DEPARTMENT OF CIVIL ENGINEERING
SEMINAR ON -
PESTICIDE INDUSTRY
SUBMITTED BY-
SOURABH M. KULKARNI
M. Tech (ENVIRONMENTAL ENGG)
ROLL NO.112020016
UNDER THE GUIDANCE OF
PROF. J.S. MAIN
2. PESTICIDE INDUSTRY Page 2
INDEX –
Sr no. Description Page No
1 Introduction 2
2 Manufacturing
process
6
3 Water
consumption& waste
generated
12
4 Waste characteristics 13
5 Effluent standards 14
6 Pollution effects 16
7 Volume & strength
reduction
20
8 Recovery techniques 21
9 Effluent treatment 22
10 References 30
3. PESTICIDE INDUSTRY Page 3
INTRODUCTION-
Pesticides are defined as the substance or mixture of substances used to prevent,
destroy, repel, attract, sterilise, mitigate any insects. Generally pesticides are
used in three sectors viz. agriculture, public health and consumer use. The
consumption of pesticide in India is about 600 gms / hectare, where as that of
developed countries is touching 3000 gms / hectare.
There are about 150 industrial units manufacturing pesticides (technical) and
About 500 industrial units engaged in formulations in the country.
There is a wide range of pesticides found used in non-agriculture situations such
as industries, public health and for a number of purposes in the home. Domestic
use of pesticides is mainly as fly killer, ant killer, repellants, rodenticides and
fungicides etc. By and large industrial use of pesticide is of vital importance in
the industries such as wood and carpet, wood preservation etc.
Pesticide commonly used in the agriculture can be grouped as-
Insecticides – It control the insects that damage the crops. The classes are
chlorinated hydrocarbons, organophosphates, carbamates. They are used
on lawns, vegetables, grapes, tobacco, forest trees etc.
Organic fungicides and bactericides- They control plant molds & other
diseases. Their classes are dicarboximides,dithiocarbamates,synthetic
fungicides. Fungicides protects plants from fungal growth. They are used
on grain, vegetables, grapes etc.
Organic herbicides- Herbicides are used to control the weeds which
compete with crop plants with water, nutrients, space & sunlight. Their
classes are phenoxyaliphathic acid,nitroanilines,aryaliphatic acid. They
used on the grapes, fruit trees, sugar beets, beans, rice etc.
Pesticide Production in India-
India is the largest producer of pesticides in Asia and ranks twelfth in the world
for the use of pesticides.
Pesticide is manufactured as technical grade products and consumable
pesticides are then formulated .The installed capacity of technical grade
4. PESTICIDE INDUSTRY Page 4
pesticide was 1,45,800 tonnes during March 2005, and the production in the
financial year 2004-05 was 94,000 tonnes.
Year Production tonnes/ year
2001-02 81800
2002-03 69600
2003-04 84800
2004-05 94000
Comparison of pesticide use in India and worldwide-
Uses of pesticides in India –
Sector Use
Agriculture For control of pests, weeds, rodents,
etc.
Public health For control of malaria, dengue fever,
cholera.
Other than agriculture & public health Control of vegetation in forests and
factory sites, fumigation of buildings
and ships
Domestic Household and garden spray, control
of animals and birds
Personal For application of clothing & skin
care
5. PESTICIDE INDUSTRY Page 5
Material building Incorporation of paints, glues, plastic
protection, sheeting, foundation of
buildings etc.
State wise production in India during the year 2005/06 –
State Production in MT/year
Gujarat 36.05
Maharashtra 32.16
Andhra Pradesh 2.665
Kerala 2.407
Karnataka 0.11
Major pesticide control legislation in India-
Legislation Regulatory body
Insecticide Act, 1968 and the
Insecticides Rules, 1971
Ministry of Agriculture Department of
Agriculture & Cooperation
Environment Protection Act, 1986 Ministry of Environment & Forest
Prevention of Food Adulteration Act,
1954
Ministry of Health & Family Welfare
Persistence in soil of some pesticides-
Insecticides, Herbicides and their
groups
Persistence
Organophosphates 7-84 days
DDT 10 yrs
Carbamate 2-8 weeks
Aliphathic acid 3-10 weeks
Diuron 16 Months
BHC 11 yrs
Toxaphene 6 yrs
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PROCESS DESCRIPTION-
The pesticide are produced in two stages the manufacture of pesticide and the
formulation of the final product. Most of the pesticide pesticide process are
batch process, the remaining are continous processes.
Raw material-
The raw material used in the production of pesticide might include a large
number of organic or inorganic compounds. There are various types of raw
material or chemicals used for the different pesticide manufacturing such as
herbicide, insecticide, fungicides etc. For ex. In the manufacturing process of
malathion the raw materials used are DDPA (dimethyl-dithio phosphoric acid)
and DEM (diethyl maleate). For DDT chlorine ðanol, chlorobenzene are use
as a raw materials.
Reactor system-
In this reactor system the chemical reactions, chemical process is takes place in
the presence of chemicals. There are various types of unit processes such as
oxidation, nitration, condensation etc.
Fractionation system-
Fractionation is a separation process in which a certain quantity of
a mixture (solid, liquid, solute, suspension or isotope) is divided up in a number
of smaller quantities (fractions) in which the composition changes. The
recovery of certain chemicals can be done in this process.
Dryer-
Drying is a mass transfer process consisting of the removal of water or another
solvent by evaporation from a solid, semi-solid or liquid. This process is often
used as a final production step before selling or packaging products.
Scrubbers-
The identified priority pollutants from the pesticide process / operation can be
efficiently removed using suitable scrubbing liquor in a mass transfer device.
The liquor and gas can contact each other while both are flowing in the same
direction (co-current flow), in opposite directions (counter current flow), or
while are flows perpendicular to the other (cross flow). The scrubbing liquor
used for the removal of gaseous pollutants can be by-product, in the form of
9. PESTICIDE INDUSTRY Page 9
slurry or a chemical solution. Scrubbing can be carried out in spray columns,
packed bed columns, plate columns, floating bed scrubbers and liquid-jet
scrubber or venturi scrubbers. The wastewater generated from the scrubbing
action is further goes to wastewater treatment plant.
Packaging-
The technical grade pesticide shall be packed in dry and clean containers. There
are various types of drums are used for packaging of pesticides. The types are
depend on the pesticide which is packed. The mild steel drums, HDPE drums,
aluminium clad containers are used for liquid pesticide packaging. The packing
drums are used are capacity of 10, 25, 50,100,200 lits. The drum should be
temperproof. The closer should be provided so for not allowing leaking the
drum. The drums should be sturdy.
Formulating unit/ industry -
After a pesticide is manufactured in its relatively pure form (the technical grade
material) the next step is formulation – processing a pesticide compound into
liquids, granules, dusts, and powders to improve its properties of storage,
handling, application, effectiveness, or safety. The technical grade material may
be formulated by its manufacturer or sold to a formulator/ packager.
The most important unit operations involved in formulation are dry mixing and
grinding of solids, dissolving solids, and blending. Formulation systems are
virtually all batch-mixing operations.
Active ingredient-
These are the active ingredient which is the technical form of pesticide.
Mill-
In this unit the grinding of pesticides is done. Some of the pesticides are in solid
state which can cause problem in the mixing with the solvents in mixing tank.
So for proper mixing the grinding is done before it.
Mixing tank-
Liquid formulating-
Liquid formulations contain mixtures of several raw materials, including
pesticide active ingredients, inert ingredients, and a base solvent, and may also
contain emulsifiers or surfactants. The solvent may be water or an organic
10. PESTICIDE INDUSTRY Page 10
chemical, such as isopropyl alcohol or petroleum distillate. In some cases, the
formulation is an emulsion and contains both water and an organic solvent.
Solid materials, such as powders or granules, may also be used as part of a
liquid formulation by being dissolved or emulsified in the solvent to form a
liquid or suspension. The formulated product may be in a concentrated form
requiring dilution before application, or may be ready to apply.
Typical liquid formulating lines consist of storage tanks or containers to hold
active and inert raw materials, and a mixing tank for formulating the pesticide
product.
A storage tank may also be used on the formulating line to hold the formulated
pesticide product, prior to a packaging step. These raw materials are either
piped to the formulation vessel from bulk storage tanks, or added directly to the
vessel from drums, bags. Typically, water or the base solvent is added to the
formulation vessel in bulk quantities.
The formulating line may also include piping and pumps for moving the raw
material from the storage tanks to the mixing tank, and for moving formulated
pesticide product to the packaging line. Other items that may be part of the line
are premixing tanks, stirrers, heaters, bottle washers, and air pollution control
equipment. Some lines may also contain refrigeration units for formulation,
storage units and other equipment.
Dry formulation-
Dry formulations contain active and inert ingredients; the final product may be
in many different forms, such as powders, dusts, granules, blocks, solid objects
impregnated with pesticide, pesticides formed into a solid shape or
microencapsulated dusts or granules. They are formulated in various ways,
including mixing powdered or granular actives with dry inert carriers, spraying
or mixing a liquid active ingredient onto a dry carrier, soaking or using pressure
and heat to force active ingredients into a solid matrix, mixing active
ingredients with a monomer and allowing the mixture to polymerize into a
solid, and drying or hardening an active ingredient solution into a solid form.
These dry pesticide products may be designed for application in solid form or to
be dissolved or emulsified in water or solvent prior to application.
Dry formulating lines typically have tanks or containers to hold the active
ingredients and inert raw materials, and may include mixing tanks, ribbon
blenders, extruding equipment, high-pressure and temperature tanks for
impregnating solids with active ingredient.
11. PESTICIDE INDUSTRY Page 11
Raw materials for dry pesticide products may be liquid or solid. Liquid raw
materials may be stored in drums, or bottles. Dry raw materials may be stored in
silos, metal drums, fiber drums, bags, or boxes. Liquid raw materials may be
pumped, poured, or sprayed into formulation vessels, while dry raw materials
are frequently transferred to formulation equipment by screw conveyors
(consisting of a helix mounted on a shaft and turning in a trough), through
elevators, or by pouring.
Packaging-
Liquid packaging-
Many liquid formulations are packaged by simply transferring the final product
into containers. Small quantities of product are often manually packaged by
gravity feeding the product directly from the formulation tank into the product
container. For larger quantities, the process is often automated. Formulated
product is transferred to the packaging line through pipes or hoses, or is
received from a separate formulating facility, and placed in a filler tank. A
conveyor belt is used to carry product containers, such as jugs, bottles, cans, or
drums, through the filling unit, where nozzles dispense the appropriate volume
of product. The belt then carries the containers to a capper, which may be
automated or manual, and then to a labeling unit. Finally, the containers are
packed into shipping cases.
Dry packaging-
Dry formulations are also packaged by simply transferring the final product into
boxes, drums, jugs, or bags. Again, small quantities or bags are typically
packaged manually using a gravity feed to carry the product from the
formulating unit into the containers or bags. Larger quantities may be packaged
on an automated line, similar to liquid packaging lines.
12. PESTICIDE INDUSTRY Page 12
Water consumption & waste generation-
Wastewater generated from pesticides manufacturing processes consists
of reaction water from chemical processes, process solvent water, process
stream wash water, product wash water, spent acid etc.
Because of the nature of pesticides and their components, wastewaters
generated from manufacturing plants usually contain toxic. The pollutants
or groups of pollutants likely to be present in raw wastewater include
halomethanes, cyanides, haloethers, phenols, heavy metals ,pesticides etc.
Washing and cleaning operations provide the principal sources of
wastewater in formulating and packaging operations. Because these
primary sources are associated with cleanup of spills, leaks, area wash
downs, and storm water runoff.
Wastewaters from formulation and packaging operations typically have
low levels of BOD, COD and TSS, and pH is generally neutral.
Also use of wet scrubber contributes to the waste water generation.
Waste water contributes from packaging of technical grade pesticides.
Waste generation-
Manufacture plant Kg/ton of active
ingredient manufacture
200
Formulation plant Kg/ton of formulated
product
3-4
14. PESTICIDE INDUSTRY Page 14
Central pollution control board Effluent standards for Pesticide
industry -
Parameter Standards
Temperature Shall not exceed 5 deg. above the
receiving water temp.
pH 6.5-8.5
Oil & grease 10
BOD 3 days 27° C Technical unit 100
BOD 3 days 27°C Formulation unit 30
Total suspended solids 100
Bio assay test 90% survival of fish after 96 hrs in
100% effluent
Specific Pesticides In mg/l
DDT 0.01
Benzenl Hexachloride 0.01
Endosulfan 0.01
Carbonyl 0.01
Malathion 0.01
Fenitrothion 0.01
Diamethoate 0.45
Phorate 0.01
Sulphar 0.03
2,4 D 0.4
Methyl parathion 0.01
Phenathoate 0.01
Pyrethrums 0.01
Ziram 1
Paraquate 2.3
Proponil 7.3
Copper sulphate 0.05
Copper oxychloride 9.6
Other pesticides 0.10
15. PESTICIDE INDUSTRY Page 15
Heavy Metals In mg/l
Copper 1
Managanese 1
Zinc 1
Mercury 0.01
Antimony as sb 0.1
Any other metal like Nickel etc Shall not exceed 5 times the Drinking
water standards of BIS
Organics In mg/l
Phenol & Phenolic compounds as
C6H5OH
1
Inorganics In mg/l
Arsenics as As 0.2
Cyanide as CN 0.2
Nitrate as NO3 50
Phosphate as P 5
Emissions In mg/Nm3
HCL 20
Cl 2 5
H2S 5
P2O5 as H3PO4 10
HBr 5
NH3 30
Particulate matter with pesticide
compounds CH3Cl
20
HBr 5
16. PESTICIDE INDUSTRY Page 16
Pollution Effects -
Effects on Streams –
Presence of suspended solids causes odor & lowers the DO level in
stream which is deadly to aquatics. It also increases the turbidity of water
course & enhances flooding by diminishing the stream bed volume.
High BOD values will increase the organic matters & create unpleasant
tastes, odors & general septic conditions due oxidation of organic matters.
It decreases DO level & affects deadly to aquatic life.
All salts, some even in low concentration, are toxic to certain forms of
aquatic life. chlorides are toxic to fish in 400ppm.
Effects on Sewers –
Suspended solids may cause clogging of sewers by getting accumulated
at an invert.
The waste contains sulphates which are converted into H2S gas which
can form odour problem.
The presence of sulphates also forms crown corrosion.
Effects on STPs –
BOD exerted by organics imposes a load on treatment plant. Increase in
BOD load requires greater biological unit capacity for its treatment which
increases daily operating expenses.
Suspended solids from industrial waste sometime may settle more rapidly
than that of sewage solids, which are necessary to be removed at shorter
intervals, otherwise they will build up excessively at tank bottom & cause
septic conditions. Slower settling of industrial solids will require longer
detention period & larger basins which increases the unit cost.
17. PESTICIDE INDUSTRY Page 17
Effects of Pesticide on Ecology-
Water-
Pesticides are found to pollute every source of water including wells.
The main routes through which pesticides reach the water are:
1. It may drift outside of the intended area when it is sprayed.
2. It may percolate, or leach, through the soil.
3. It may be carried to the water as runoff.
4. It may be spilled accidentally.
They may also be carried to water by eroding soil.
Soil-
Many of the chemicals used in pesticides are persistent soil contaminants whose
impact may endure for decades and adversely affect soil conservation. The use
of pesticides decreases the general biodiversity in the soil.
Air-
Pesticides can contribute to air pollution. Pesticide drift occurs when pesticides
suspended in the air as particles are carried by wind to other areas, potentially
contaminating them. Volatile pesticides applied to crops will volatilize and are
blown by winds to nearby areas posing a threat to wildlife. Sprayed pesticides
or particles from pesticides applied as dusts may travel on the wind to other
areas, or pesticides may adhere to particles that blow in the wind, such as dust
particles.
Effects on human-
Pesticides may cause acute and delayed health effects in those who are
exposed. Pesticide exposure can cause a variety of adverse health effects. These
effects can range from simple irritation of the skin and eyes to more severe
effects such as affecting the nervous system, mimicking hormones causing
reproductive problems, and also causing cancer. Strong evidence also exists for
other negative outcomes from pesticide exposure including neurological, birth
defects, fetal death, and neurodevelopment disorder.
18. PESTICIDE INDUSTRY Page 18
Effects on Biota-
Plants-
Nitrogen fixation, which is required for the growth of higher plants, is hindered
by pesticides in soil. The insecticides DDT, methyl parathion, and especially
pentachlorophenol have been shown to this effect. It results in reduced nitrogen
fixation and thus reduces crop yields.
Animals-
Pesticides inflict extremely widespread damage to biota, and many countries
have acted to discourage pesticide usage through their Biodiversity Action
Plans. Animals may be poisoned by pesticide residues that remain on food after
spraying, for example when wild animals enter sprayed fields or nearby areas
shortly after spraying. Widespread application of pesticides can eliminate food
sources that certain types of animals need, causing the animals to relocate,
change their diet. Poisoning from pesticides can travel up the food chain. It
affects on reproductive system of animals.
Aquatic life-
A major environmental impact has been the widespread mortality of fish and
marine invertebrates due to the contamination of aquatic systems by pesticides.
This has resulted from the agricultural contamination of waterways through
fallout, drainage, or runoff erosion, and from the discharge of industrial
effluents containing pesticides into waterways.
Most of the fish in Europe's Rhine River were killed by the discharge of
pesticides, and at one time fish populations in the Great Lakes became very low
due to pesticide contamination.
Pesticide surface runoff into rivers and streams can be highly lethal to aquatic
life, sometimes killing all the fish in a particular stream. Application of
herbicides to bodies of water can cause fish kills when the dead plants rot and
use up the water's oxygen, suffocating the fish. Some herbicides, such as copper
sulfite, that are applied to water to kill plants are toxic to fish and other water
animals at concentrations similar to those used to kill the plants. Some
pesticides can cause physiological and behavioural changes in fish that reduce.
Insecticides are more toxic to aquatic life than herbicides and fungicides.
19. PESTICIDE INDUSTRY Page 19
Birds-
Pesticides had created striking effects on birds, those in the higher trophic levels
of food chains. Pesticides will also kill grainand plant-feeding birds, and the
elimination of many rare species of ducks and geese. Populations of insect
eating birds such as partridges, grouse, and pheasants have decreased due to the
loss of their insect food in agricultural fields through the use of insecticides.
20. PESTICIDE INDUSTRY Page 20
Volume & Strength reduction-
Waste segregation is an important step in waste reduction. Process
wastewater containing specific pollutants can often be isolated and
disposed of or treated separately.
Wastewater generation can be reduced by general good housekeeping
procedures such as substituting dry cleanup methods for water wash
downs of equipment and floors. This is especially applicable for
situations where liquid or solid materials have been spilled.
Flow measuring devices and pH sensors with automatic alarms to detect
process upsets are two of many ways to effect reductions in water use.
Prompt repair and replacement of faulty equipment can also reduce
wastewater losses.
Floor wash water, surface runoff, scrubber effluents, water can be reused.
Use wet clothes instead of direct water application for floor wash. Use
proper chemicals instead of water to remove colours on floors.
Use of automated filling systems for reactors, tanks and drums to
minimize spills.
Use of low-volume, high efficiency cleaning systems (e.g. high pressure
spray nozzles and steam cleaners).
Periodic cleaning of lines, using a plastic or foam “pig”.
Liquid pesticide packs should not be overfilled, and filling equipment
should be designed to avoid splashing / foaming.
Proper and adequate training for the workers & awareness about
environment.
21. PESTICIDE INDUSTRY Page 21
Recovery techniques-
There are various techniques available for recovery however, concerning most
important techniques for pesticide manufacturing industries to control priority
pollutants emission are (i) absorption, (ii) adsorption, (iii) condensation, (iv)
chemical reaction and (v) incineration (vi)Reverse osmosis & Ultrafiltration.
Absorption-
The identified priority pollutants from the pesticide process / operation can be
efficiently removed using suitable scrubbing liquor in a mass transfer device.
The liquor and gas can contact each other while both are flowing in the same
direction (co-current flow), in opposite directions (counter current flow), or
while are flows perpendicular to the other (cross flow). The scrubbing liquor
used for the removal of gaseous pollutants can be by-product, in the form of
slurry or a chemical solution. Scrubbing can be carried out in spray columns,
packed bed columns, plate columns, floatingbed scrubbers and liquid-jet
scrubber or venturi scrubbers.
Adsorption-
Adsorption is a surface phenomenon by which gas or liquid molecules are
captured by and adhere to the surface of the solid adsorbent. It is desirable for
removal of contaminant gases to extremely low levels and handling large
volume of gases with quite dilute contaminants.
22. PESTICIDE INDUSTRY Page 22
Source control of pesticide waste -
Source control and waste minimization can be extremely effective in reducing
the costs for in plant controls and end-of-pipe treatment, and in some cases can
eliminate the need for some treatment units entirely. The first step is to prepare
an inventory of the waste sources and continuously monitor those sources for
flow rates and contaminants. The next step is to develop in-plant operating and
equipment changes to reduce the amount of wastes. The following are some of
the techniques available for the pesticides manufacturing facilities.
Waste segregation is an important step in waste reduction. Process wastewaters
containing specific pollutants can often be isolated and disposed of or treated
separately in a more technically efficient and economical manner. Highly acidic
and caustic wastewaters are usually more effectively adjusted for pH prior to
being mixed with other wastes. Separate equalization for streams of highly
variable characteristics is used by many plants to improve overall treatment
efficiency.
Wastewater generation can be reduced by general good housekeeping
procedures such as substituting dry cleanup methods for water washdowns of
equipment and floors. This is especially applicable for situations where liquid or
solid materials have been spilled. Flow measuring devices and pH sensors with
automatic alarms to detect process upsets are two of many ways to effect
reductions in water use. Prompt repair and replacement of faulty equipment can
also reduce wastewater losses. Reactor and floor washwater, surface runoff,
scrubber effluents, and vacuum seal water can be reused.
Treatment methods of pesticide waste -
Activated carbon adsorption treatment
Hydrolysis
Chemical oxidation
Resin adsorption
23. PESTICIDE INDUSTRY Page 23
Activated carbon adsorption-
Activated carbon adsorption is a well-established process for adsorption of
organics in wastewater, water, and air streams. Granular activated carbon
(GAC) packed in a filter bed or of powdered activated carbon (PAC) added to
clarifiers or aeration basins is used for wastewater treatment. In the pesticide
industry, GAC is much more widely used than PAC. Figure shows the process
flow diagram of a GAC system with two columns in series, which is common in
the pesticide industry. Activated carbon studies on widely used herbicides and
pesticides have shown that it is successful in reducing the concentration of these
toxic compounds to very low levels in wastewater. Some examples of these
include BHC, DDT, 2,4-D, toxaphene, dieldrin, aldrin, chlordane, malathion,
and parathion. Adsorption is affected by many factors, including molecular size
of the adsorbate, solubility of the adsorbate, and pore structure of the carbon. A
summary of the characteristics of activated carbon treatment that apply to the
pesticide industry follows.
1. Increasing molecular weight is conducive to better adsorption.
2. The degree of adsorption increases as adsorbate solubility decreases.
3. Aromatic compounds tend to be more readily absorbed than aliphatics.
4. Adsorption is pH-dependent; dissolved organics are generally adsorbed more
readily at a pH that imparts the least polarity to the molecule.
Activated carbon adsorption is mainly a waste concentration method. The
exhausted carbon must be regenerated or disposed of as hazardous waste.
Thermal regeneration is the most common method for GAC reactivation,
although other methods such as washing the exhausted GAC with acid, alkaline,
solvent, or steam are sometimes practiced for specific applications.
Other adsorbing materials besides GAC have also been investigated for treating
pesticide containing wastewaters such as pine bark, a wood charcoal.
24. PESTICIDE INDUSTRY Page 24
Resin adsorption-
Adsorption by synthetic polymeric resins is an effective means for removing
and recovering specific chemical compounds from wastewater. The operation is
similar to that of GAC adsorption. Polymeric adsorption can remove phenols,
amines, caprolactam, benzene, chlorobenzenes, and chlorinated pesticides . The
adsorption capacity depends on the type and concentration of specific organics
in the wastewater as well as pH, temperature, viscosity, polarity, surface
tension, and background concentration of other organics and salts. Regeneration
can be conducted with caustic or formaldehyde or in solvents such as methanol,
isopropanol, and acetone. Batch distillation of regenerant solutions can be used
to separate and return products to the process. In study regarding the treatment
of effluent from a manufacturer of chlorinated pesticides with Amberlite XAD-
4 and GAC. Results indicated that the leakage of unadsorbed pesticides from
the XAD-4 column was significantly lower than that from the GAC column. An
economic analysis indicated that pesticide waste treatment via XAD-4 resin and
chemical regeneration would be more economical than GAC adsorption using
external thermal regeneration.
Chemical oxidation-
Chemical oxidation modifies the structure of pollutants in wastewater to similar,
but less harmful, compounds through the addition of an oxidizing agent. During
chemical oxidation, one or more electrons transfer from the oxidant to the
targeted pollutant, causing its destruction.
One common method of chemical oxidation, referred to as alkaline chlorination,
uses chlorine (usually in the form of sodium hypochlorite) under alkaline
conditions to destroy pollutants such as cyanide and some pesticide active
25. PESTICIDE INDUSTRY Page 25
ingredients. However, facilities treating wastewater using alkaline chlorination
should be aware that the chemical oxidation reaction may generate toxic
chlorinated organic compounds, including chloroform, bromodichloromethane,
and dibromochloromethane, as byproducts. Adjustments to the design and
operating parameters may alleviate this problem, or an additional treatment step
(e.g., steam stripping, air stripping, or activated carbon adsorption) may be
required to remove these byproducts.
Chemical oxidation can also be performed with other oxidants (e.g., hydrogen
peroxide, ozone, and potassium permanganate) or with the use of ultraviolet
light.Although these other methods of chemical oxidation can effectively treat
pesticide wastewaters.
Hydrolysis-
Hydrolysis is a chemical reaction in which organic constituents react with water
and break into smaller (and less toxic) compounds. Basically, hydrolysis is a
destructive technology in which the original molecule forms two or more new
molecules. In some cases, the reaction continues and other products are formed.
Because some pesticide active ingredients react through this mechanism,
hydrolysis can be an effective treatment technology for pesticide wastewater.
The primary design parameter considered for hydrolysis is the half-life, which is
the time required to react 50% of the original compound. The half-life of a
reaction generally depends on the reaction pH and temperature and the reactant
molecule (e.g., the pesticide active ingredient). Hydrolysis reactions can be
catalyzed at low pH, high pH, or both, depending on the reactant molecule. In
general, increasing the temperature increases the rate of hydrolysis.
26. PESTICIDE INDUSTRY Page 26
Disposal of pesticide Wastes –
1) Incineration
2) Deep well disposal
3) Ocean disposal
Incineration -
Incineration is an established process for virtually complete destruction of
organic compounds. It can oxidize solid, liquid, or gaseous combustible wastes
to carbon dioxide, water, and ash. In the pesticide industry, thermal incinerators
are used to destroy wastes containing compounds such as hydrocarbons (e.g.,
toluene), chlorinated hydrocarbons (e.g., carbon tetrachloride), sulfonated
solvents (e.g., carbon disulfide), and pesticides. More than 99.9% pesticide
removal, as well as more than 95% BOD, COD, and TOC removal, can be
achieved if sufficient temperature, time, and turbulence are used. Sulfur- and
nitrogen-containing compounds will produce their corresponding oxides and
should not be incinerated without considering their effects on air quality.
Halogenated hydrocarbons not only may affect air quality but also may corrode
the incinerator. Also, organometallic compounds containing cadmium, mercury,
and so on, are not recommended for incineration because of the potential for air
and solid waste contamination.
Using the proper type of incinerator and operating conditions to destroy the
pesticide wastes, the incineration system must be equipped with the proper
emission controls to ensure that toxic gases and particulates do not escape into
the environment. The ash (which may contain hazardous substances) must be
properly disposed. Many wet collection systems (scrubbers) can be used for
removing gaseous pollutants. The various types of scrubbers available include
venturi, plate, packed tower, fiber bed, spray tower, centrifugal, moving bed,
wet cyclone, self-induced spray, and jet. Dry collection equipment is available
for the removal of particulate pollutants and includes settling chambers, baffle
chambers, skimming chambers, dry cyclones, impingement collectors,
electrostatic precipitators, and fabric filters. The incinerator ash, scrubber water,
and particulate collection can then be landfilled, chemically treated, or
otherwise processed for disposal.
Incinerator type Temp °C
Fluidized bed 982
Fume 1664
Cyclonic 1664
Rotary kiln 815
28. PESTICIDE INDUSTRY Page 28
The Indofill chemicals Ltd. Have a large scale plant for the manufacture of
pesticide located at Thane is selected for making ETP. The company
manufactures Dithane which is one type of pesticide. The plant works in 3 shifts
for all 7 day in a week. The industry discharges about 44 thousand litrs of waste
per day.
Screening –
Fine mesh screens are provided to remove fine matters from pesticide
wastes.
Equalisation tank-
Equalization tank provided in pesticide industry consists of a wastewater
holding vessel or a pond large enough to dampen flow and/or pollutant
concentration variation that provides a nearly constant discharge rate and
wastewater quality. The detention time taken here is about 24 hrs. In this there
are 2 equalisation tanks are provided.
Settling tank-
The NaOH is added to the settling tank for the correction of pH before the
extended aeration process.
Fenton oxidation-
In this the dose of H2O2 is given about 2500mg/l for the oxidation & FeSO4 as
a catalyst dose about 833mg/l. With the ratio about H2O2:Fe as 1:3. & removal
percentage is about 80%.Before the Fenton oxidation the acid dosing is given
for the lower the pH value because it will work only at lower pH value. After
the Fenton process the pH is increased by addition of NaOH.
Extended aeration-
The extended aeration is complete mix flow regime. The process employs low
organic loading, high MLSS, long detention time, low F/M. As the influent
coming from the pesticide waste the assumed removal efficiency is here about
65%.
Secondary settling tank (SST) –
The biomass is generated in the aeration tank is flocculent & quick settling it is
separated from the aeration sewage in secondary tank & recycled continuously
to the aeration Tank as essential future of the process.
29. PESTICIDE INDUSTRY Page 29
Effluent sump-
The treated effluent is collected in this sump & is given for the further treatment
of activated carbon.
Activated carbon treatment –
Activated carbon adsorption is process for adsorption of organics in wastewater
from pesticide industry. In the pesticide industry, GAC is widely used. The
treatment removes the concentration of pesticides at very low level. The effluent
from the sump is pumped into the activated carbon tower.
Process MLSS
(mg/l)
MLVSS/
MLSS
F/M HRT
(hrs.)
Vol.
Loading
(kg
BOD/m3)
SRT
(days)
Qr/Q BOD
rem-
oval(%)
Kg
O2/kg
BOD
removal
Air
req./kg
BOD
removal
Extended
aeration
complete
mix flow
3000-
8000
0.6 0.15-
0.05
18-
36
0.2-0.4 20-30 0.35-
1.5
65 1-1.2 100-135
Parameter Waste
characteristics
Fenton
Oxidation
Settling tank Extended
Aeration
(65% removal)
SUSPENDED
SOLIDS (98%)
2000 40
COD (80%) 1372 274.4 96.04
MANGANESE
( 98%)
215 4.3 1.1
ZINK (98%) 4 0.08 0.02
30. PESTICIDE INDUSTRY Page 30
References-
EPA report on Pesticide industry
Use of Fenton's Reagent for Removal of Pesticides from Industrial
Wastewater- research paper
Environmental, Health, and Safety Guidelines for Pesticide
Manufacturing, Formulation, and Packaging- WHO report
PFPR Operations- EPA report
Ecological Effects of Pesticides- document by Calicut university, India
Pesticide use and application: An Indian scenario- research paper
Treatment of Pesticide Industry Wastes- by Wang & Hung
Industrial waste water treatment- A.D. Patwardhan
Central pollution control board- website
I S Codes on pesticides