treatment of textile weastwater

7/31/2019 Treatment of Textile Weastwater

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Introduction

Bangladesh is heavily involved in textile production and export. A lot of textile mills were

established in the country mostly in and around Dhaka city in last two decades. A large number

of these mills generate and discharge waste waters. It was reported by the various organizationand monitoring authority that the pollution of the rivers and canals in and around Dhaka is well

above their acceptable level. Various agencies are trying to safeguard the clean environment.

Bangladesh Government has already issued various forms of warning and red alerts to theconcerned industries. A lot of textile wet processing industries have already installed effluent

treatment plants (ETP) and many of them are at various stages of installing ETP's.

There are various types of textile wet processing plants e.g. (i) the woven dyeing plants and (ii)knit dyeing plants. The technique for dyeing of textile materials mainly depends on the type of

fiber. Some widely used fiber that are produced and exported from Bangladesh includes Cotton,

wool, silk, linen, polyester, nylon, viscose, acrylics etc. These fibers can also be classed into two

main classes e.g. (i) Natural fiber-those produced naturally e.g. cotton, jute, wool silk etc. (ii)Synthetic fiber- man made fiber that are produced from petroleum product. Dyeing of the above

mentioned fibers are somewhat different and each of them requires a different class of dye.Different dyestuffs require different types of chemicals and auxiliaries to apply them into the

fabric or textile product. As a result the characteristics of the textile waste water vary

significantly. Due to variation of characteristics, textile waste water requires various types oftechniques to treat them.

Description of Textile Indu-stries Polluting Environment

Textile wet processing plants of Bangladesh may be classed as (i) Knit dyeing units, (ii) Woven

dyeing units, (iii) Denim plants, (iv) Printing units, and (v) Garments washing units.

Knit Dyeing Units

Knit dyeing industries are one of the most highly environment polluting textile industries in

Bangladesh. These are mainly engaged in processing export oriented knit fabrics. Different typesof textile products require different methods of treatment procedure. The treatment procedure


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and machines of woven fabric dyeing and knit fabric dyeing are quite different. This is because

knit fabrics are soft and require gentle handling while woven fabrics are relatively stiffer andmay be subjected to tougher treatment options. For this reason knit fabrics are dyed in winch

types of dyeing machine where treatment is carried out in a very high M:L ratio like 1:150-200.

It was found in various studies that nearly 150 to 200 liters of water is required to dye one kg of

knitted goods. Considering all the factors it was found that a knitting factory of 10 tonproduction capacity generates nearly 100 to 150 M3 of waters per hour. However all the water

mentioned above are not equally harmful. Some are very severely polluted while some are

mildly polluted. On average, it was found that 50% of waters are polluted and needs to be treatedand the rest of the water can discharged directly or subjected to very mild treatment. Thus a

general guide line for knit dyeing is that for a factory of 10 ton dyeing capacity may require

effluent treatment plant of 40 60 M3/hr treatment capacity.

Woven Dyeing Units

Woven dyed fabric is dyed in a different way than knitted fabrics. The volume of waste watergenerated from a woven dyeing factory is very low in comparison to knit dyeing process. Apartfrom this the characteristics of woven dyeing plants are different from those of knit dyeing

plants. Before weaving, sizing is carried out to increase the strength of warp yarns. The main

component of sizing is Starch. Wet process starts with desizing to remove the starch and other

sizing agents from the fabric otherwise subsequent process and dyeing will not be perfect. Thedischarge from a desizing unit is highly polluted. Some of the pollutants of woven dyeing units

are as follows: Starch and other sizing materials, unfixed dyes, poor washing-off of dyes,

machine cleaning wastes during start-up, shut-down and changes of color and style, salts andalkalies etc. Generally woven dyeing is carrie dout at a very low m:l ratio which could be as low

as 1:5 (for continuous dyeing) hence the quantity of waste water is very low but the level of

toxicity of the effluent is very high.

Denim Plants

Denim plants are particularly weaving plants and produce denim fabrics. In denim plant dyeingand sizing is carried out on the warp yarns and after weaving various types of finishing

operations are carried out. The effluent discharged from sizing and dyeing units are highly

polluted as compared to that of all other wet processing plants and cause substantial impact on

the environment. Off course the volume of effluent is relatively lower than that of knit dyeing.The characteristics of dyed effluent of the denim is somewhat different from that of knit dyeing

plants as because vat dyes are used for denim plant while reactive and dispersed dyes are used

for dyeing knit goods, however the quantity of generated effluent is extremely low e.g. 1:1.5.

Printing Units


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Pollutants associated with printing include suspended solids, solvents, foam, color and metals,

and in general, large volumes of water are consumed during the washing-off stages. The main

areas of environmental pollution of textile printing includes dyes containing metals,objectionable surfactants, air emissions, water from washing the print blanket, leftover print

paste, excess paste from drums, screens and pipes, use of urea as this increases the nitrogen inthe effluent. Like denim the quantity of effluent of textile printing industry is very low but highly

polluted.

Garments Washing Units

At present there are a lot of garment washing plants which are operating in Bangladesh. There

are basically two types washing e.g. (i) normal washing and (ii) denim washing. The denim

washing involves a lot of operations like desizing, enzyme washing, finishing etc.These can beachieved by chemical or mechanical methods. Process involves use of volatile chemical. The

pollution loads from garments washing plants are not much but quantity is large and requiressome sort treatment.

Important Pollutants

Various types of toxicities are found in the textile wastewaters. However in order to monitor

them Department of Environment (DOE) has identified the Biochemical Oxygen Demand

(BOD), Chemical Oxygen Demand(COD), Total Suspended Solids (TSS), Total DissolvedSolids (TDS), pH, Oils and grease, color and temperature etc. are most harmful for environment.

The polluting parameters of other industries will vary to some extent. Pollutant concentration in

effluents for various textile industries varies significantly.

The Effect of the Release of Wastewater Pollutants on Ecosystems

and Human Health

Releases to surface watersSeveral environmental and health impacts resulting from insufficient wastewater treatment havebeen identified in the scientific literature and actions need to be taken to reduce these impacts.

These impacts can include negative effects on fish and wildlife populations, oxygen depletion,

beach closures and other restrictions on recreational water use, restrictions on fish and shellfish

harvesting and consumption and restrictions on drinking water consumption.

Some examples of pollutants that can be found in wastewater and the potentially harmful effects

these substances can have on ecosystems and human health include:

decaying organic matter and debris can use up the dissolved oxygen in a lake so fish andother aquatic biota cannot survive;


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excessive nutrients, such as phosphorus and nitrogen (including ammonia), can causeeutrophication, or over-fertilization of receiving waters, which can be toxic to aquaticorganisms, promote excessive plant growth, reduce available oxygen, harm spawning

grounds, alter habitat and lead to a decline in certain species;

chlorine compounds and inorganic chloramines can be toxic to aquatic invertebrates,algae and fish;

bacteria, viruses and disease-causing pathogens can pollute beaches and contaminateshellfish populations, leading to restrictions on human recreation, drinking water

consumption and shellfish consumption;

metals, such as mercury, lead, cadmium, chromium and arsenic can have acute andchronic toxic effects on species.

other substances such as some pharmaceutical and personal care products, primarilyentering the environment in wastewater effluents, may also pose threats to human health,

aquatic life and wildlife.

Releases to AirThe process of collection and treatment of wastewater also results in the release of certain

volatile chemicals into the air. The chemicals tyically released in the largest volume include;methane, carbon dioxide, oxides of nitrogen, hydrogen sulfide, mercaptans, chlorine (if used in

the treatment process) and various other chemicals can be released to a smaller extent.

Releases to LandThe process of removing both inorganic and organic suspended solids from the wastewater

results in large quantities of solid waste. In typical treatment facilities, the inorganic solids (grit,debris) and other non-biodegradable materials are sent to landfill. Many secondary treatment

facilities collect the organic solids and process them in a digester to recover methane gas for

energy production. Once the organic solids have been completely digested (no further methaneproduction), various options are available to the treatment facility. These solid wastes can beland applied as asoilfertilizer/conditioner, incinerated for further energy recovery, sent to landfill,

or to deep well injection.

Effluent Treatment Methods

Effluent treatment is an important subject from undergraduate to Ph.D. level students. Various

philosophies, thoughts and approaches were suggested to deal with textile as well as othereffluents. Some of the important effluent treatment steps are described below.


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Effluent Segregation

The effluent generated from a textile wet processing plant is of varying type having differentlevel of toxicity and chemical characteristics. For example the effluent characteristics ofScouring, Bleaching and Dyeing and printing will be quite different from each other. One of the

important task of any effluent treatment approach would be to separate them according to theirlevel of toxicity. The idea is that at first vigorous treatment is carried out with the most polluted

waters and at certain stage the less polluted waters are added to the streams. Off course the costof chemicals is almost same whether effluent treatment is carried out together or separately, but

it the cost of power and capacity and cost of motors and pumps makes a big difference. It can be

summarize that from economic point of view, it is better to treat small amount of highly toxiceffluent rather than a treating a large amount less toxic effluent, because in the latter case the

capacity of motor and pump would be higher and more electricity will be required to run those

motors and pumps. Therefore one of the important task of effluent treatment approach is to

separate or segregate the effluents according to their level of toxicity. This result in a moreeffective treatment system as a smaller volume of waste water is treated (resulting in lower

capital and operating costs) and it allows for the use of specific treatment methods rather than

trying finding one method to treat a mixture of waste with different characteristics. Thesegregated clean streams can then be reused with little, or no, treatment elsewhere in the factory.

Treatment Technologies

Effluent can be treated in a number of different ways depending on the level of treatment

required. These levels are known as preliminary, primary, secondary and tertiary (oradvanced).Three mechanisms for treatment can be divided into three broad categories: physical,

chemical and biological. ETP manufacturers use these mechanisms and processes together either

fully or partially in a effluent treatment plant.


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Preliminary or Pretreatment

Removal of large solids such as rags sticks, grit and grease that may damage equipment or result

in operational problems. Preliminary treatment consists of mainly (i) Screening which is adoptedin a effluent treatment plant to remove relatively large solid wastes. and (ii) Equalization &

Skimming - to remove grease & oil and homogenize and to remove some BOD & COD.

Primary Treatment

Primary treatment is intended for removal of floating and settleable materials i.e. suspendedsolids and chemical organic matter. Primary treatment consists of the following treatments;

A. Coagulation - to coagulate the suspended solid to coagulate

B. Flocculation - to flocculate by coagulants

C. Neutralization - to adjust the pH between 6.5 to 8.5

D. Sedimentation to precipitate small suspended solids

All the above processes contribute to removal of substantial amount of all the polluting

parameters.

Secondary Treatment

Secondary treatment is carried out to removel biodegradable organic matters which includeremoval of BOD and COD & decomposition of organic matter. Biological treatment can be

aerobic and anaerobic.

Tertiary/Advanced Treatment

Since the effluent from the textile industry is complex and variable, it is unlikely that a single

Treatment technology will be suitable for total effluent treatment. Tertiary treatment includesremoval of residual suspended solids/ dissolved solids. Most of the effluent treatment plants usethe Adsorbents (granular activated carbon, silica, clays, fly ash, synthetic ion-exchange media,

natural bio adsorbents, synthetic bio adsorbents). In Bangladesh the following two types of filters

are used:


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A. Granular Media Filtration-To removes TSS and any other pollutants in the form of particle. This filter is also useful to

protect the Activated Carbon Filter (ACF) from overloading by pollutants such as

particulates, organics.

B. Activated Carbon Filter-Carbon adsorption is a proven process in tertiary treatment for the processing biologically treated

wastewaters, and is one of the many processes used in the advanced treatment of waste-waters.

The ACF is used to remove relatively small quantities of refractory orga-nics, as well as

inorganic such as sulfides and heavy metals remaining in an otherwise well-treated wastewater.

Sludge Management & Disposal

Sludge disposal to separate the sludge from the thick slurry and then dispose of the sludge as

dried cake.

Description of Important Treatment Process

Screening, Equalization and Skimming

Screens are very simple materials having iron bars in the form of square grids. Effluent is

allowed to pass through the grid when large and coarse solid materials are arrested by it allowing

smaller particles and effluent to pass through. In some several grids are use with diminishing gridsizes.

Equalization tank is a large chamber which is designed for retention time of 12 hours. This

means if the rate effluent is 30 cubic metre then the capacity of the equalization tank has to be 30X 12 = 360 cubic meters. The equalization tank is specially built where air is blown by two

blowers alternately round the clock on continuous basis. The purposes of equalization are (i) to

supply oxygen so that DO level increases and (ii) to mix various types effluents and (iii) to


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reduce the temperature of the water.On the top surface of the equalization tank there is a scrapper

used to skim the oily substances.

Coagulation and Flocculation

From the equalization tank the effluent is taken to a small tank which is also called flash mixing

tank of small retention time. In the flash-mixing tank coagulants like lime (Calcium Hydroxide)and flocculants like ferrous sulfate (FeSO4) are dosed. This is done for coagulation and removal

of the total dye particles. The basic idea of adding coagulant is to bring together all the

suspended and dye particles so that they can be precipitated out in the flash mixing tank and

flocculation tank by coagulation and flocculation mechanism. The chemical reaction that occursin the coagulation and flocculation process is shown below;

CaO + H2O Ca (OH) 2

The above reaction take place in flash mixing tank when lime reacts with water and we getcalcium hydroxide solution. This solution reacts with the ferrous sulfate solution, which as

follows

Ca (OH) 2 + FeSO4 CaSO4 + Fe (OH) 3+ FeSO4 (Unreacted) + Fe (OH) 2


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Adequate quantity of polyele-ctrolyte polymer solution is dosed in the flocculation tank followed

by flash mixing tank to enhance the process of color removal by the flocculation process. Asubstantial amount BOD and COD etc. are removed in the coagulation and flocculation process.

Precipitation and Sedimentation in Tube Settler -1. (To remove the flocs materials)

From the flocculation tank the effluent is taken to the tube settler- 1 tank where the dyes andsuspended particles are precipitated. The flocs formed are removed in the downstream tube

settler 1 by the help of tube settler media. The effluent will further flow by overflow system to

the pH correction tank where requisite quantity of acid will be dosed and pH will be adjusted asper the requirement.

pH Correction (To adjust the inlet pH)

The effluent from tube settler- 1 tank is then taken to the pH correction channel for

neutralization, where 33% HCl acid is dosed for neutralizing the pH value around 7 to 8. It may

be mentioned that different dyed effluent may generate different pH level. For acrylic and basic

dyeing the pH is on the acidic side as dyeing medium is acidic, in that pH correction should bemade by adding additional alkali. The pH correction tank is designed for hydraulic retention time

of around 1 -2 minutes and is provided with slow speed agitator for thoroughly mixing of waste

with acid/alkali to maintained pH value.

Biological Treatment

The objective of biological treatment of industrial wastewater is to remove, or reduce the

concentration of organic and inorganic compounds. Biological treatment process can take manyforms but all are based around microorganisms, mainly bacteria. These microorganisms use

components of the effluent as their food and in doing so break them down to fewer complexes

and less hazardous compounds. In the process the microorganisms increase in number. There aretwo main types of processes, these involve suspended microbial growth (e.g. activated sludge)

and attached microbial growth (e.g. fixed film). With both approaches large populations of

microorganisms are brought into contact with effluent in the presence of excess oxygen. In both

systems the microbial population has to be retained in the reactor. With suspended growthsystems microbes grow in small aggregates or flocs (this is known as activated sludge).Activated

sludge (AS) leaves the reactor with the treated effluent but is settled out in a clarifier and

returned to the aeration unit. If the amount of AS is excessive some may be disposed of rather

than being recycled.


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In fixed film systems the microbial population grows as a thin layer (a bio-film) on the surfaceof an inert support medium. The classical fixed film system is known as a percolating or

biological filter and uses small stones as a medium to support microbial growth. In the more

modern system microbes grow on plastic supports. In the traditional percolating filters effluent is

sprayed over the medium and trickles through a packed bed with oxygen entering from the air. Inmore recent reactor designs, the medium (usually plastic) is submerged in effluent and air is

blown into the base of the reactor. Traditional percolating filters require large areas of land and

are unlikely to be of use in Bangladesh due to land costs. Submerged fixed film reactors usingplastic media require much less land and are potentially of value in treating textile wastes. These

plastic media are now widely used and known as Moving Bed Biological Reactor (MBBR).

MBBR systems require a final clarifier to remove particles of biofilm that become detached from

the medium. However, this material is not recycled to the reactor.

The chemical reactions that took place in the MBBR reactor can be defined according to thefollowing three processes;

A. Oxidation process

COHNS + O2 + Bacteria + DAP and UREA CO2 + NH3 + Energy + Other end Products DAPand Urea are used as food for the microorganism.

B. Synthesis Process

COHNS+O2+ Bacteria C5H7NO2 (New bacteria)

C. Endogenous Respiration

C5H7NO2 + 5O2 CO2 + NH3 + 2H2O

Apart from the above basics reaction there are some other reactions that take place in the MBBR

reaction tanks. During aeration the oxygen reacts with C, S and N which is shown below.

C + O2 CO2

S + O2 SO2

N + O2 NO2


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Some untreated ferrous sulfate and ferrous hydroxide reacts with oxygen and the reactions are as

follows,

FeSO4 + O2 Fe2 (SO4) 3

Fe (OH) 2 + O2 Fe (OH) 3

While most of the activated sludge is recycled some may be surplus to requirements and needs tobe disposed of, as does detached biofilm from film reactor. This material must be disposed

appropriately so that the pollutants now present in this sludge do not enter the water cycle. The

treated liquid is discharged to the environment or taken for further treatment depending on the

desired standard of effluent quality or the required use of the wastewater. Biological treatment

plants must be carefully managed as they use live microorganisms to digest the pollutants. Forexample some of the compounds in the wastewater may be toxic to the bacteria used, and pre-

treatment with physical operations or chemical processes may be necessary. It is also importantto monitor and control pH as adverse pH may result in death of the microorganisms. The ETP

must be properly aerated and must be operated 24 hours a day, 365 days a year to ensure that the

bacteria are provided with sufficient food (i.e. wastewater) and oxygen to keep them alive. Like

humans microorganisms need a balanced diet with sources of carbon, nitrogen, phosphorus andsulfur. While textile wastes have enough carbon and sulfur (sulfate) they are generally lacking in

nitrogen and phosphorous containing compounds. If the microorganism are to grow and work

effectively they are likely to need addition of nutrients. Normally materials such as urea andammonium phosphate are added. It is possible to replace these nutrients by substituting the liquid

portion of effluent from toilets, which is rich in nitrogen and phosphorus containing chemicals

(the solid portion may cause problems). Both activated sludge and fixed film systems can

produce high quality effluent but both in have advantages and disadvantages. In the AS processthe settling and recycling of AS to the aerobic reactor is vital, and the settling process can be

difficult to accomplish. Fixed film/MBBR systems do not require recycling of biomass and so do

not present this problem.


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Anaerobic digestion

Anaerobic digestion is the biodegradation of complex organic substances in the absence of

oxygen to yield carbon dioxide, methane and water. It is an effective process for treating highCOD wastes (e.g. size, desize washing and scouring) and the methane that is produced can be

utilised as energy for heating etc. The reducing conditions in an anaerobic digester have beenfound to cause decolorisation of azo dyes through cleavage of the azo bond and subsequent

destruction of the dye chromophore. Complete mineralisation of these degradation products does

not take place and aromatic amines may be present in the effluent from the digester (Carliell etal., 1995).

Effluent treatment plants in Bangladesh

According to the Environmental Conservation Rules 1997, industrial units and projects have

been classified into four categories (Green, Orange A, Orange B, and Red) based on

environmental impact and location. Fabric dyeing and chemical treatment industries fall underthe Red category and when applying for site clearance must submit to the Department of

Environment an ETP plan, including the layout and location. When the design has been approved


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by the Department of Environment and the ETP has been constructed, then red category

industries can apply for an environmental clearance certificate.

From very rough estimation there are nearly 600-700 textile wet processing industries in

Bangladesh. So far nearly 300 to 400 factories have already set up or at various stages of setting

up effluent treatment plant (ETP)

Factors to Consider

Any factory needing to install an ETP has to consider several factors. For example, information

about the factory's wastewater is required, including quantity and quality. To get this information

the factory will have to take samples and have them analyzed at a reputable laboratory. Some ofthe factors to be considered are presented in the schematic on the next page.

In Bangladesh mainly two types of effluent treatment plants are operating e.g (i) Physico

Chemical Plants(PCP), (ii) Biological Plants (BP). Both of them uses the above mentioned

treatment processes fully or partially.

Some key information about two types of plants

1. Initial investment- Cost establishment of PCP is very low in comparison to BP, nearly 1:15-20

2. Land area required by PCP is very small in comparison to BP

3. Running Cost of PCP is nearly 20 Tk/M3 of effluent while this cost of BP is around Tk 5-6.

Thus PCP adds nearly 3-5/kg of knitted goods while BP adds only Tk 1-1.25.

Environmental Pollution by other meansEmissions to Air

Air pollution results from various textile processes and from energy production and has been

identified as the second greatest pollution problem for the textile industry. Those from process

emissions include volatile organic substances and particulate matter from the printing, dyeing,and curing of fabric, and the handling of chemicals. The emission of volatile organic substances

may lead to the production of photochemical oxidants and cause unpleasant odours. The textile

industry requires a great deal of heating and the type of fuel determines the nature of the

pollutants. Boilers are one of the major point sources for air emissions, producing nitrogen andsulphur oxides. Fugitive sources of air pollution include volatile emissions from processed fabric

stored in warehouses and chemical spills. Emissions to air can be minimized by designing

products that do not require the use of volatile chemicals, optimizing boiler operations and

reducing the use of solvents.


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Noise Pollution

There are various ways noise is created in textile industries. The main source of noise is due to

running of the equipments. So far two types machines were diagnosed to be vulnerable for

human being and these are various types of looms and rotor spinning machine. Apart from thisnoise is also arises from fan systems, transport to and from the industry.

Hazardous Waste

Hazardous wastes are defined as wastes, or combination of wastes, that pose a threat to human

health or living organisms because they are lethal, non-degradable, and persistent in nature and

can cause detrimental cumulative effects. These wastes can be solids, liquids, gas or sludges

Most textile operations produce little or no hazardous waste, but some (10-20%) may be

generators of hazardous waste. The main sources from the textile industry are heavy metals andsolvents. Other components include acids, alkalis, bleaches, adhesives, polymers, cross-linking

agents, detergents, dye carriers, chemical finishes, biocides, weed killers, paint strippers andsolvents. The remainder (75% (m/m)) is considered to be non-hazardous. Carriers containing

chlorinated aromatics are considered to be extremely hazardous and their use today is limited

(Swedish Environmental Protection Agency, 1989). Organic phosphorous compounds (e.g.

flame-proofing and completing agents) may contain organic bromine compounds, such asdecabromine diphenyl oxide and antimony trioxide, which are bioavailable and

bioaccumulative.

The most effective means of reducing hazardous waste from the textile industry is one of

avoidance by pre-screening all chemicals. This is most easily achieved by studying the material

safety data sheet (MSDS). If hazardous chemicals are required, proper handling and storage is

important and workers should be trained in these areas.


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Conclusion/Suggestions

a) Proper management of wastewater will reduce the overall volume of effluent. Not all effluent

in a textile wet processing plant are equally harmful for the environment, dyeing effluents are

more harmful than rinsing waters, the rinsing water should be separated from dyed water and canbe discharged without or with minimum treatment.

b) If all the factories do not install appropriate ETP and do not run them properly then there willbe an unequal price competition among fabric producers where the honest ETP owners will

always lose the battle.

c) Use of synthetic sizes rather than starch based sizes will reduce the high toxicity of the

effluent generated from denim plants. The starch-based sizes contribute to highest amount of

BOD.

d) Government should reduce or exempt the tariffs and taxes on the synthetic sizes, so thatsynthetic sizes can replace cheap starch based sizes that contribute to very high BOD.

e) Attempt should be made to explore the idea of developing woven sector. The material to

liquor ratio of woven dyeing is very low in comparison to knit dyeing. Less effluent means less

raw water will be required, this in turn will reduce the amount of gas/electrical energy requiredto pump and heat water. The profit margin of woven garments is also very high.

f) Attempt should be made to explore the idea of developing synthetic production. Thecharacteristics of effluent from synthetic dyeing is different from that of cotton products. The

pollution load is less for synthetic. Less effluent means less raw water will be required, this in

turn will reduce the amount of gas/electrical energy required to pump and heat water. The profit

margin of woven garments is also very high.

g) Reconstitution of processed effluent should be examined for every stage of processing likescouring, bleaching, mercerization, dyeing and finishing baths. This will reduce the quantity of

ultimate effluent.

h) Decisive and efficient use of dyes, chemical and auxiliaries will reduce the quantity and

toxicity of the effluent to a great extent. Selection dyes, chemicals and auxiliaries that generate

lower pollutants will reduce ultimate pollution load.

i) Like many developed countries, Government can offer free water and wastewater test

facilities. Though some people may take advantage of this facility but for greater interest of thecountry this type of initiative will help in understanding, administering and researching the over

all-environmental pollution scenario.


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j) Environment is violated not only by the textile processing plants but also by many other

factories and establishments like slaughtering houses, sweet manufacturers, bakeries, poultry

farms etc. Their pollution load should be examined and should also be brought under strict

scrutiny.

k) Universities may research on managing and handling effluent..Research is essential to studythe effect and toxicity of various dyes, chemicals and auxiliaries used in our country. Research is

also necessary to study and upgrade the existing treat-ment procedures in order to reduce

operating cost and also to combat future violation of the environment.

l) Entrepre-neurs can be encouraged to set up industries far away from the crowded greater

Dhaka. This will at least reduce the pollution burden on the Dhaka dwellers to some extent.

Setting up of industries near big rivers or coastal areas could be a much better option because

effluents can be directly released into the .

Thank You,,,,,,,,,,,,,,,,,,,,,,,,,,,,

treatment of textile weastwater

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