1.0 Introduction1.0 Introduction

1.1 Origin of the Report:

Bangladesh has enormous environmental problems in industrialization sector which need

to be considered seriously. We were orally authorized to prepare a Term Paper on the

theme- ‘Industrial Hazards and their effects on environment in Bangladesh’ for the

fulfillment of the course ‘Environmental Issues in Business (BUS 303)’- by our

honorable course teacher Mr. Shahriar Kabir. Therefore we have worked on and prepared

this Term Paper on “Environmental Pollutions in Leather Industries of Bangladesh” with

our little but complete effort. The report will follow the formalities, rules and regulations

of a formal report presentation. The topic decided for the report is “Business and Politics

in Bangladesh” and is to be submitted on 17th December, 2009.

1.2. Objective of the Report:

a) Broader objective:

The broader objective of this project report is to determine the current pollution state

caused by these leather industries in our environment and the vital reasons behind

such pollution

.

b) Specific objectives:

A few specific objectives of this project are given below:

To brief an overview of the working process of the leather industries in

Bangladesh

To give an idea about the harmful effects occurring by the toxic wastes

discharged by the tanneries

To discuss ideas about solving such a major adversity of our country

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1.3 Scope:

This report is intended to provide background information on Tannery Industries in

Bangladesh and the beginning of this industry. It also includes an overview of the

condition, level of pollution and some environmental issues in this field of industry. The

scope of the study is the processing unit of different types of leather in the Hazaribagh

industrial area in Dhaka city, Bangladesh. Two samples of the tannery industries had

been chosen randomly for the purpose of the report.

1.4. Methodology:

1.4.1. Data Collection Method:

In this report, most of the data were collected from primary sources. But, some secondary

sources were used to find out company profile and to support the writings of the Term

Paper.

At the very beginning of ours task, we studied about the potential information about the

tanneries stated at the greater parts of Dhaka. Then we found out our research sector and

also determined our survey areas. After that, we visited few tanneries at Hazaribagh,

which was the biggest shot for making this report. We observed the two specific

tanneries, their entire work process, and their waste disposal procedure as per instruction

and finally prepared the data for the Term Paper.

a) Source of Data:

Primary Data regarding the report has been collected through visiting the reputed

leather industries stated in Hazaribagh industrial area in person and by

interviewing the local workers and residents.

Secondary Data has been collected from the website.

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b) Sampling Plan:

i) Sample Unit and size: Our sampling unit is the leather industries processing both the

local and export quality leather. For that we have visited two tanneries: Yousuf Leather

Corporation Ltd. which is a producer of export quality leathers and a local leather factory,

Ibrahim Leathers.

ii) Sample area: The sampling area is the Hazaribagh industrial area of Dhaka city.

c) Data Collection Instruments:

Observation and personal interview was the only data collection instrument as these

methods were more acceptable, accurate and flexible and less time consuming.

1.5. Limitations of the Report:

The proposed report is expected to be plagued with several limitations. These are as

follows:

Time constraints on the part of the owners and the managers in providing us with

information.

Also time constraint on our part, because in this semester we all are in constant

pressure. We tried our best to collect various information

The report will not cover all information about the leather industry. It will only

cover till the processing of raw leather

We have not covered all information about the leather industry of the country but

only two tanneries in the Hazaribagh industrial area

Limitation due to improper accessibility

Limitations due to lack of research expertise.

Some information may be overlooked

Despite of all these limitations, we have given our best efforts. We also tried to make the

report as informative and as comprehensive as possible.

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2.0. An Overview of Leather Industry

2.1. Industry Background:

The leather industry sector is the fourth largest foreign exchange earner of Bangladesh

contributing about six per cent of the total export earnings. Bangladesh earns more than

8.0 billion taka - 11 per cent of all the export earnings – by exporting leather and

leather goods. The leather industries are mostly situated in the densely populated

residential area surrounded by slums, where people are living ignorantly in one of the

worst polluted areas in the world. The condition to describe the living conditions of the

slums is beyond capability.

Figure: Residuals near Hazaribagh main drain

Bangladesh is capable of producing 180 million square feet of leather per year. But these

industries produce 150 metric tons of solid waste every day contaminating the

environment and water of the metropolis. 59 per cent of the total wastage comes from

processing of hides and skin, and accumulates in the swamp-sludge, experts in the

environment sector said. They said, "Part of the solid waste is collected by the Dhaka

City Corporation (DCC) and taken to landfill sites." A recent research conducted by

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Professor S M Imamul Huq, Chairperson of Soil, Water and Environment Department of

Dhaka University revealed that out of 214 tanneries in the country, except for two BATA

and Dhaka Leather Complex- none of the tanneries has a treatment plant as required by

the law. Most of the waste effluents are subjected to natural decomposition in the

environment, causing serious pollution problems affecting soil, water, air and human life.

Figure: Dumped leather wastes polluting environment

The leather export is growing and at the same time conditions of the poor are

deteriorating. The finding said that the existing industries in most cases do not have any

effluent treatment plants for neutralizing the toxicity and harmful effects of their

pollutants. As per the requirement of this course, we have visited two tanneries of

Hazaribagh, which are Yousuf Leather Corporation Ltd. and Ibrahim Leathers. First one

is one of the largest export quality leather producing tannery and the second one produces

comparatively lower quality leather from local raw materials. We have also tried to visit

Bay Tanneries Ltd. which is another export quality leather producing tannery but could

not be successful due to some allowance reasons.

2.2. Types of Tanning:

Tanning is the process of making leather which does not easily decompose the raw

materials. Often this uses tannin, an acidic chemical compound. The whole tanning

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process is categorized into two types according to the tanning process followed in our

country:

Vegetable tannage and

Chrome tannage

Vegetable-tanned leather: tanned using tannin and other ingredients found in vegetable

matter, tree bark, and other such sources. It is supple and brown in color, with the exact

shade depending on the mix of chemicals and the color of the skin. It is the only form of

leather suitable for use in leather carving or stamping. Vegetable-tanned leather is not

stable in water; it tends to discolor, and if left to soak and then dry it will shrink and

become less supple and harder. In hot water, it will shrink drastically and partly

gelatinize, becoming rigid and eventually brittle. Boiled leather is an example of this

where the leather has been hardened by being immersed in hot water, or in boiled wax or

similar substances.

Chrome-tanned leather: invented in 1858, is tanned using chromium sulfate and other

salts of chromium. It is more supple and pliable than vegetable-tanned leather, and does

not discolor or lose shape as drastically in water as vegetable-tanned. It is also known as

wet-blue for its color derived from the chromium. More esoteric colors are possible using

chrome tanning.

Figure: Chemicals used in chrome-tanning process

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The vegetable tannage process is much environment friendly but the leather produced

from such process does not ensure the durability of the leather. So most tanneries are

using the chrome technology nowadays which emits harming toxic gas and liquid waste

and thus environment is being polluted. Again, the main element that ensures the

durability of export quality leather, Basic Chrome Sulphet (BCS) or Chromasol B, is one

of the main components of causing Cancer. So no doubt that this is a threat to the whole

human race who are related to this industry.

2.3. The Whole Tanning Process:

Raw animal skins go through several steps during the tanning process. Depending on the

type of hide used and the desired end-product, the steps taken during tanning can vary

greatly. Tanneries use to collect hides from the ‘haat’, situated around the country. After

collecting, preparing hides begins by curing them with salt. Curing is employed to

prevent putrefaction of the protein substance (collagen) from bacterial infection during

the time lag that might occur from procuring the hide to when it is processed. Curing

removes excess water from the hides and skins using a difference in osmotic pressure.

Figure: Curing process of animal skin with salt and then pressing in packs

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The moisture content of hides and skins get greatly reduced. In wet-salting, the hides are

heavily salted, then pressed into packs for about 30 days. In brine-curing the hides are

agitated in a salt water bath for about 16 hours. Generally speaking, methods employed

for curing make the chance of bacterial growth greatly unfavorable. Curing can also be

done by preserving the hides and skins at a very low temperature.

Figure: Soaking of leather in water tank

In a process known as soaking, the hides are then soaked in clean water to remove the salt

and increase the moisture so that the hide or skin can be further treated. After soaking, the

soaked hides and skins are taken for the next operation where these are treated with milk

of lime with or without the addition of "sharpening agents" like sodium sulfide, cyanides,

amines etc. The weakening of hair is dependent on the breakdown of the disulfide link of

the amino acid called Cystine, which is the characteristic of the keratin class of protein

which gives strength to hair and wools. The hydrogen atoms supplied by the sharpening

agent reduce the Cystine molecular link to Cysteine, and the covalent disulfide bond links

are ruptured. This weakens the keratin. To some extent, the weakening produced by

sharpening also contributes to "unhairing," as the hairs break down.

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The majority of hair is then removed using a machine, with remaining hair being

removed by hand using a dull knife, a process known as scudding. Depending on the end

use of the leather, hides may be treated with enzymes to soften them in a process called

"bating." But before bating, the pH of the collagen is brought down to a lower level so

that enzymes may act on it. This process is known as "de-liming."

Once bating is complete, the hides and skins are treated with a mixture of common salt

and Sulphuric Acid, in case a mineral tanning is to be done. This is done to bring down

the pH of collagen to a very low level so as to facilitate the penetration of mineral tanning

agent into the substance. This process is known as "pickling." The common salt (sodium

chloride) penetrates the hide twice as fast as the acid and checks the ill effect of sudden

drop of pH.

Figure: Various steps in the processing of leather

Tanning can be performed with either vegetable or mineral methods that we have

mentioned before. Before tanning, the skins are unhaired, degreased, desalted and soaked

in water over a period of 6 hours to 2 days. To prevent damage of the skin by bacterial

growth during the soaking period, biocides, such as pentachlorophenol, are used.

Vegetable tanning uses tannin. The tannin is a class of polyphenol astringent chemical

that occurs naturally in the bark and leaves of many plants. Tannins bind to the collagen

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proteins in the hide and coat them causing them to become less water-soluble, and more

resistant to bacterial attack. The process also causes the hide to become more flexible.

The primary barks used in modern times are chestnut, oak, tanoak, hemlock, quebracho,

mangrove, wattle and myrobalan. Hides are stretched on frames and immersed for several

weeks in vats of increasing concentrations of tannin. Vegetable tanned hide is flexible

and is used for luggage and furniture.

Mineral tanning usually uses chromium in the form of Basic Chromium Sulfate (BCS) or

Chromasol B. It is employed after picking. Once the desired level of penetration of

chrome into the substance is achieved, the pH of the material is raised again to facilitate

the process. This is known as "basification". In the raw state chrome tanned skins are blue

and therefore referred to as "wet blue." Chrome tanning is faster than vegetable tanning

and produces stretchable and long-lasting leather which is excellent for use in handbags

and garments. But for the harmful affects of the Chrome, some tanneries are now using

both vegetable and chrome tanning altogether to prevent the toxication- that we came to

know from few of the tannery owners.

Figure: Chrome-tanned leather10

Figure: Drying and finishing of leather

Depending on the desired product, the hides then go through a dyeing process, which also

involves adding moisture back into the skin. Hides which have been vegetable tanned are

bleached and them soaked with oils, soaps, greases and waxes to make them more

pliable. Rolling leather means running the skins through a machine that works to firm the

leather to make it stronger. After the rolling process has finished, leathers are stretched,

where they dry out in a heat controlled room. Through such dyeing and finishing, the raw

leather becomes suitable for exporting. This was the finishing for exporting processed

leather to foreign countries.

Figure: Finished leather ready for exporting

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3.0. Analysis and Findings

3.1. Pollution Occurring from Leather Industries:

220 tanneries located in Bangladesh, mostly n Dhaka, are releasing a large quantity of

toxic waste at the time of processing of leather, causing a severe environmental pollution.

The pollution is seriously affecting the livelihood of some 0.1 million people in and

around the Hazaribagh area of the capital city. Some 194 of the tanneries are now housed

in the city's Hazaribagh area, which is on the brink of an environmental disaster. The

quality of liquid waste discharged from these tanneries varies from 10 to 15 gallons per

square feet of hides and skins processed. This comprising waste water, organic particular

and toxic chemicals is discharged in open drains and ultimately finds its way onto land

surfaces and in natural waters in the vicinity. As a result, water, air, soil, shelter and food

are getting continuously polluted.

Figure: Regular drainage scenario nearby the tanneries

However, it is heartening to note that only a fifth of the raw stock can in practice be

converted into reliable leather, the remains form waste or by-product. Some of the raw

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materials, such as hair, soluble proteins and fat have to be removed during processing to

prepare the collagen fiber structure of the hide for tanning; some parts of the leather also

have to be trimmed or shaved during the production process. Residual chemicals from the

leather manufacturing process, such as sulphide used for unhairing and chromium

employed for the tanning process, can contribute to the waste. Micro-pollutants, such as

insecticides from raw stock, are also of growing concern. Chemical analysis suggests that

tannery wastes are characterized by strong colors, high biochemical oxygen demand, high

pH and high dissolved salts. Disposal of these wastes into water course or onto land, with

or without prior sedimentation, creates a great problem in the environment in the vicinity.

The images shown below give us some solid evidence about the chemical toxic disposed

by the tanneries. Here, two colors of liquid wastes can be seen of which, one is sodium

chloride and other one is the Basic Chrome Sulphet (Chromasol B) which emits

dangerous toxic gaseous wastes and strong bad-odor and pollution altogether.

Figure: Toxic liquid wastes disposed by the tanneries

One thing that was not much known to us- was the difference between the local and the

export quality leather processing tanneries. By visiting two of the tanneries, we could

visualize the difference by our own. The export quality leather producer, Yousuf Leather

Corporation Ltd. let us know that they use the total raw chemical in their tanning process,

while the local ones like we have visited Ibrahim Leathers, they take away their liquid

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waste, which is the chemical saturated water after the soaking process, and use that

Chrome-water in their processing.

Figure: Liquid wastes taken by the local tanneries

So, the export quality leather factories are getting much free from a huge pollution as a

part of their wastes is taken away. But the local workers are not concerned about it this

much. The local tanneries are still drawn into lack of using resources, technology and the

result is some more pollution. These tanneries take the liquid waste of the bigger

tanneries, put the wet-salted leather into a deep house, pour the water waste into it and

mix them by hand using long bamboos or sticks.

Figure: Tanning, open dumping of wastes and drying of tanned leather

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They don’t even follow any safety measures like wearing gloves or using chemical

resistant uniforms to protect themselves from toxic wastes. Again the tanned leathers are

dried into open air or roof without controlling any heat or air. After their own tanning

process, they dispose the liquid and solid both wastes into the biggest drain of

Hazaribagh which already seems to be blocked much. Even they dump the solid wastes

into open places. Thus they are helping to emit gaseous, solid and liquid wasted to get

spread into the whole environment.

The effluents are produced mostly during tanning and dying. The 149 operating tanneries produce

14910 metric tons of effluents or waste water during the peak time, about 9100 metric tons during

the off-peak period. The effluents contain dissolved lime, hydrogen sulfide, acids, chromium

dyes, oils, organic matter and suspended solids. The waste water is discharged into open drains

and ultimately finds way onto land surface and into natural waters in the vicinity. About 3000

tons of sodium sulfide and nearly 3000 tons of basic chromium sulfates are used each year for

leather processing and tanning. The other chemicals used in the tanning industry are non-ionic

Figure: Blocked drainage system in Hazaribagh

wetting agents, bactericides, soda ash, calcium oxide, ammonium sulfate, ammonium

chloride, enzymes, sodium bisulfate, sodiumchlorite, sodium hypochlorite, sodium

chloride, sulfuric acid, formic acid, sodium formate, sodium bicarbonate, vegetable

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tannins, syntans, resins, polyurethane, dyes, fatemulsions, pigments, binders, waxes,

lacquers and formaldehyde. The tannery waste with high concentration of dissolved

solids, suspended solids, to prevent physical, chemical and biological pollution of the

receiving body of water, chloride, color, ammonia etc. is being discharged every day in

the receiving water.

Of all the tanneries at Hazaribagh, only a few belong to the Bangladesh Tannery

Association. A large amount of waste produced by these tanneries is discharged in natural

water bodies directly or indirectly through two open drains without any treatment. The

water in the low-lying areas near Hazaribagh, with a direct link to the Buriganga river, is

polluted in such a degree that it has become unsuitable for public uses. In summer when

the rate of decomposition of the waste is higher, serious air pollution is caused in the

whole of Hazaribagh area, including a part of not too far high-class residential area, by

producing intolerable obnoxious odors. The pollutants of tannery wastes are of morganic,

organic and toxic nature and require elaborate treatment before disposal. Out of 214

tanneries, 200 are located near the capital’s river systems – the Turag to north-west, the

Buriganga to the south-west and the Sitalakhya to the south-east, with Turag flowing into

the Buriganga. The tanneries discharge the effluents and wastes into the river system

causing a large area of acid sludge alongside the flood protection embankment and the

liquid wastes are dumped in the river through a flood control regulator-cum-sluice.

During monsoon months, the flood protection embankments protect Dhaka from heavy

flooding while making it difficult to flush-out waste water, thereby creating

environmental hazard. During the dry season the waste water is flushed out into the river

causing pollution of the river water and affecting the aquatic flora and fauna. The water

quality of the river Buriganga during wet season and dry season are heavily polluted so

that dissolved oxygen in the river water is found to be nil during the dry season and no

fish or other aquatic animals can live in this condition.

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Figure: Fish and Chicken food made from solid animal wastes

Bangladesh is capable of producing 180 million square feet of leather per year. But these

leather factories produce 150 metric tons of solid waste every day contaminating the

environment and water of the metropolis. 59 per cent of the total wastage comes from

processing of hides and skin, and accumulates in the swamp-sludge. Part of the solid

waste is collected by the Dhaka City Corporation (DCC) and taken to landfill sites. Some

other solid wastes, like the animal fats are used in making soaps, some removed parts of

the half-processed leather are burnt and mixed with some other components and fed to

the fish and chicken as food. But the dangerous thing is the Chrome mixed with these

solid wastes which can be threatening lately for the fishes and chicken. Cow-dung is a

very much affluent fuel for the people living in rural areas. But dumping of the other

solid wastes is seriously affecting the soil and plants, besides vitiating the air,

groundwater and human health.

Rice and wheat were grown in a pot experiment in soils from the tannery area. The wheat

showed delayed maturity and stunting growth while rice showed late flowering and

maturity with dark green color. In another experiment it was observed that application of

tannery effluents to soils of differing textures resulted in reduction of yield of rice, the

research said adding that the adverse effect was more pronounced in light soils than in

heavy soils. The effluent was also found to negatively affect performance, nodulation and

growth of Mung Beans (Dal).

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4.0. Recommendations & Conclusion

4.1. Recommendations:

It is not possible for an industry to carry on production without polluting the

environment. Tanneries which produce export quality leather pollute the environment

less then the tanneries processing local leather. The chemicals and the wastage from the

raw hides are being used by the local tanneries to tan leather and in producing glue, foods

of chicken and fish, soap etc. But the industries can take some steps to reduce such

toxicity. They should take some necessary steps to improve the current condition of

leather industries. These may include:

1. A large amount of waste produced by the tanneries of Hajaribagh area is

discharged in natural water bodies directly or indirectly through two open drains

without any treatment. The water in the low-lying areas near this area has a direct

link to the Buriganga River, is polluted in such a degree that it has become

unsuitable for public uses. So the first thing have to do is to construct a complete

waste management plant to reduce the toxic of tannery pollutant before the

disposal to prevent physical, chemical and biological pollution of the receiving

body of water.

2. With the prolonged delay in implementing the Dhaka Tannery Estate Project

(DTEP), the Buriganga river and millions of residents in the western part of the

capital are set to face renewed onslaught of toxic emissions in the coming years.

So, there must be a safer residual arrangement for those residents near Buriganga

and also plans should be taken to purify the water of this river.

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3. The key targets which are identified for reducing environmental impact of leather

processing are replacement of chromium, more efficient use of chemicals,

sulphide-free unhairing, possibly with hair recovery, utilization of wastes, and

reuse of water, odor control, solvent free finishing and N-free delimiting.

4. There is no denying that most of the urban-based industries in Bangladesh

pollute environment. Of them, tanneries do the extreme damage. Most of the

tanneries are located in urban areas and their relocation outside the

metropolitan city has not been done. The relocating of the tanneries stated in

Hazaribagh has already been planned but steps should be taken faster for the

sake of the survival of human and animal races.

5. The local drain lines have already been blocked partially by these tannage wastes.

So steps to clean these drains should be taken as early as possible.

As the tannery industries in Bangladesh are well established, they cannot be shifted

without enormous losses. However, efforts are in progress to shift the Hazaribagh

tanneries to a suitable place in Savar. Yet, at every stage of leather processing, clean

technology must be applied. When new industries are set up, clean technology will have

to be followed for protecting the environment.

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4.1. Conclusion:

It has become essential to treat the tannery waste to a certain degree prior to its disposal.

Despite the fact that pollution abatement is a considerable non-productive cost-burden on

leather processing, the industry itself has taken the initiative to introduce clean

technology and improve pollution control. A clean technology can overcome

environmental pollution caused by the tanneries. Physical, chemical and biological

cleaning methods for waste water are used in this sector. Physical treatments include

mainly screening and primary sedimentation, the only treatment which is provided in

most of the tanneries in Bangladesh. Today's tanners are not only hard-pressed by the

high costs of compliance with increasingly restrictive environmental legislation, but are

also faced with a confusion of competing claims for alternative clean technologies. A

practical database is required that would enable the tanner simply and rapidly to shortlist

the most appropriate technologies for these specific needs, with the aim of minimizing

the costs. The Government of Bangladesh has not shown much interest either in

environmental impact created by the industries, whereas government's concern to create

jobs usually meant that when a new factory is proposed - by local, national or

international business or agency - little attention is given to the likely environmental

impacts. But experts say that despite the zero-pollution philosophy, advocated by some

developed countries, a developing country like Bangladesh must depend on rapid

industrialization in an endeavor to upgrade the standards of living.

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