The growth of small and medium-scale industrial activities has had a positive impact on economic development in many countries. However, it has brought with it a range of problems, including pollution of water resources. This is true in Bangladesh, where the number of small industrial units is estimated to be about 50,000. Not all are polluting, but it is clear that many ecosystems are now under threat, and the livelihoods of tens of thousands of people are being affected. The most effective way to resolve this situation is to reduce effluent at source, to ensure that industrial plants take full account of the damage to the environment and do all they can to reduce this damage.
The State of Bangladeshi Water
The increasing urbanisation and industrialisation of Bangladesh have negative implications for water quality. The pollution from industrial and urban effluents in some water bodies and rivers has reached alarming levels. The long-term effects of this contamination by organic and inorganic substances, many of them toxic, are severe. The marine and aquatic ecosystems are affected, and the future public health implications of chemicals entering the food chain are incalculable.
The major causes of degradation of inland water quality are related to land-based activities combined with inadequate regulatory measures and a lack of concern from stakeholders. The underlying forces driving this are poverty, lack of institutional strength, and lack of awareness and education. Pollutants that enter the marine and coastal environment originate on land in the form of runoff from municipal, industrial and agricultural wastes, and from commercial seafaring activities.
In Bangladesh, industrial units are mostly located along the banks of the rivers, which provide transportation for incoming raw materials and outgoing finished products. Unfortunately, as a consequence, industrial units drain effluents directly into the rivers without any consideration of the environment. The most problematic industries for the water sector are textiles, tanneries, pulp and paper mills, fertiliser, industrial chemical production and refineries. A complex mixture of hazardous chemicals, both organic and inorganic, is discharged into the water bodies from all these industries, usually without treatment. The highest number of industrial locations in the country is in the North Central (NC) region, which comprises just under half of the total sector. About 33 per cent of the industries in the NC region are textiles, finished garments and tanneries, of which Dhaka district accounts for almost half and Narayanganj about 32 per cent.
The Textile Industry
Following the increase in the export market for ready-made garments, the textile industry in Bangladesh began to cater for external demand. Before that, it had largely met local needs. The Textile Policy of 1992-94 declared the textile industry as a ‘thrust sector’, and financial concessions were made for corporations entering the export market. As a result, the export of ready-made garments rose at a rate of US$5 billion every year. In addition, the local market has been growing both in consumption rates and in its overall size of population. Previously, the domestic market was dependent upon imported goods; now the local industry meets over 90 per cent of domestic demand for ready-made garments.
The textile industry uses vegetable fibres such as cotton, animal fibres such as wool and silk, and a wide range of synthetic materials such as nylon, polyester, and acrylics. The production of natural fibres is approximately equal to the amount of production of synthetic materials (of which polyester accounts for about half). The stages of textile production are fibre production; fibre processing and spinning; yarn preparation; fabric production; bleaching, dyeing and printing; and finishing. Each stages produces waste that requires proper management.
This cycle of textile production involves what are termed ‘wet processes’, which emit volatile organic compounds (VOCs). VOC concentrations vary from 10 milligrams of carbon per cubic metre (mg/m3) to 350 mg/m3. Process wastewater is a major contributor to industrial pollution. Wool processing, for example, creates 544 m3 per tonne of wastewater, contaminated with bacteria, chemicals, dyes, and bleaches. The wastewater is typically alkaline and contains solids, oil, and potentially toxic organics, such as phenols from dyeing, and halogenated organics from bleaching. Dye wastewaters are frequently highly coloured and may contain heavy metals such as copper and chromium. Wool processing may release bacteria and other pathogens. Pesticides are also sometimes used for the preservation of natural fibres, and these are transferred to wastewaters during washing and scouring operations.
The importance of pH for fish
In Bangladesh, the lining of rivers with industrial plant has a detrimental impact on local livelihoods. People rely on the rivers to supply their fish (for consumption and retail) and, in many areas, water for cleaning. Where pollution has affected the pH of the water, fish stocks are harmed and children playing and washing in the water are at risk to harmful side effects. Water (H2O) is composed of hydrogen and oxygen molecules. Neutral water is given a pH value of 7.0 (on a scale of 1 to 14), and contains equal amounts of hydrogen ions (H+) and hydroxide ions (OH-). Dissolved chemicals and minerals change the balance of those ions from a neutral state. Increase the amount of hydrogen ions (H+), and the water becomes more acid (low pH). Increase the amount of hydroxide ions (OH-), and the water becomes more alkaline (high pH). The further these values rise or fall, the more acid or alkaline the water becomes.
There is no ‘normal’ pH that applies to all fish. Because fish originate in ponds, rivers, streams, lakes, and oceans that have different pH levels, their needs are different. Saltwater fish prefer an alkaline pH of 8.0 or above. Freshwater fish thrive at the neutral to acid end of the spectrum between 5.5 and 7.5. Changes in pH can be a natural daily occurrence. However, sudden changes in pH can prove harmful or even fatal to fish. As the pH is raised it increases the toxicity of chemicals such as ammonia. In a number of species of fish, breeding occurs only within a specific pH range.
Limiting pH Values
|3.8||10.0||Fish eggs could be hatched, but deformed young are often produced.|
|4.0||10.1||Liveable limits for the most resistant fish species.|
|4.1||9.5||Range tolerated by trout.|
|—||4.3||Carp die in five days.|
|4.5||9.0||Trout eggs and larvae develop normally.|
|4.6||9.5||Limits for perch.|
|—||5.0||Limits for stickleback fish.|
|5.0||9.0||Tolerable range for most fish.|
|—||8.7||Upper limit for good fishing waters.|
|5.4||11.4||Fish avoid waters beyond these limits.|
|6.0||7.2||Optimum (best) range for fish eggs.|
|—||1.0||Mosquito larvae are destroyed at this pH value.|
|3.3||4.7||Mosquito larvae live within this range.|
|7.5||8.4||Best range for the growth of algae.|
The most significant environmental impact of pH involves synergistic effects. Synergy involves the combination of two or more substances that produce effects greater than their sum. This process is important in surface waters. Runoff from agricultural, domestic, and industrial areas may contain iron, aluminium, ammonia, mercury or other elements. The pH of the water will determine the toxic effects, if any, of these substances. For example, 4 mg/l of iron would not present a toxic effect at a pH of 4.8. However, as little as 0.9 mg/l of iron at a pH of 5.5 can cause fish to die.
The use of pesticides and other chemicals that are banned in developed countries is discouraged and, in general, is not accepted. However, in countries such as Bangladesh, sufficient regulation often does not exist and mill owners keen to maximise their profits may do so at the expense of local environment and health. Despite the large number of rules and regulations to protect water from industrial effluents, there are few enforcement programmes and a lack of institutional capability to take action. There is also a lack of skills and expertise for taking appropriate actionduring project design and implementation, to ensure that environmental concerns are properly addressed.
However, as corporations mature and become more socially and environmentally responsible, their approach to pollution the goes through four changes:
- Ignoring the problem. This always leads to maximum damage to the environment. This damage is not limited only to the local scale or neighbourhood; it can occur at the regional, and in some cases, even the global scales.
- Dispersal. This exists where polluters are convinced that ‘the solution to pollution is dilution’. This creates a smokescreen by diluting or dispersing pollution, so that its effects are less harmful or apparent.
- Trying to treat pollution through the so-called ‘end-of-pipe’ approach.
- The prevention of pollution and waste generation at the source itself.
As the diagram demonstrates, this historical trend means that established production facilities become more environmentally aware. Over time, they move towards the most efficient mode of treating pollution: prevention.
The most successful way to combat environmental pollution is to prevent it in the first instance. Pollution prevention in the textiles industry should focus on reducing water use and on more efficient use of process chemicals. Changes to textile production processes that affect type and volume of effluent include the following:
- Matching process variables (e.g. dye) to the type and weight of fabric. This can reduce waste by 10-20 per cent.
- Managing batches to minimise waste at the end of cycles.
- Avoiding non-degradable or less degradable washing and scouring chemicals.
- Using pad batch dyeing. This dyes the fabric at full width. The fabric (prepared with pre-mixed dye) is passed through a trough containing the dye and then between two heavy rollers, which force the dye into the cloth and squeeze out the excess dye. This saves up to 80 per cent of energy requirements and 90 per cent of water consumption. It also reduces dye and salt usage.
- Using fewer toxic dye carriers and finishing agents. Avoid carriers containing chlorine, such as chlorinated aromatics.
- Reusing dye solution from the dye baths.
- Recovering and reusing process chemicals.
- Controlling the quantity and temperature of the water used.
At a textile firm in the Kaliakhor region, Samiya Ahmed explains the importance of establishing and maintaining the appropriate proportions of dye:
‘The key element once you have achieved the right recipe for the shade that is required is to record the exact recipe and then follow the same method with the amount of dyes they are using and just scale it up and replicate it on the factory floor. What happens is that in our factories, the lab to bulk recipe is not followed and you end up having to re-dye and re-shade and a lot of the dyes end up going into the environment’.
The ‘recipe’ to which Samiya Ahmed refers is the combination of conditions required to create a good quality end-product:
‘What you are trying to do is get an even dye across the fabric. If you don’t get the conditions right – optimal conditions, quantities, temperature, pH – and monitor that, what you get is ring dye, which is an uneven colour across the fabric. Buyers don’t like that because the dye can rub off the fabric.’
(Dr Matthew Chadwick, Stockholm Environment Institute)
A vital part of reducing the amount of pollution released into Bangladeshi waters is convincing the textile industry of their social and environmental responsibility, as well as making it clear that it does not necessarily increase their costs. The BEEL (Bangladesh Enterprises Effluent Limitation) Project, initiated by the Stockholm Environment Institute, is working towards this end by rallying the community and engaging the industry in a process of negotiation.The causes of pollution are addressed by working with industrialists to introduce changes to production processes, to substitute chemical inputs for less harmful or more efficient ones and to treat waste. The project works with industry to establish new, and to improve existing, mitigation measures. Also with industry, and with the local communities, it works to establish appropriate community-based monitoring of pollution levels. It aims to better inform buyers of the environmental criteria they should be asking factories to meet. There is collaboration with the Department of the Environment to develop a cost-effective means of determining effluent outflow from factories, and to work with factories to reduce their pollution loads.
A Tough Decision
For communities in Bangladesh, the textile industry provides them with a paradox. On the one hand, they have proved to be major employers and have contributed to spurts of wealth and prosperity for both the immediate locality and the country as a whole. On the other hand, it is up to local communities and employees of textile firms to produce collective action that makes textile firms more socially responsible. This means making the firms more aware of their impact on the local waters. It requires dedication from local communities and the institutional framework to support them. Without support from local and national government, the communities and workers affected by the textile industry will remain powerless.
United Nations Environment Programme. (2001). Bangladesh State of the Environment Report.
UNIDO and UNEP. Guidance and Training Manual: How to Establish and Operate a Cleaner Production Centre. Paris: UNEP
World Bank. (1998). Pollution Prevention and Abatement Handbook: Textiles. Washington: World Bank Environment Department.
Bangladesh Centre for Advanced Studies www.bcas.net
Stockholm Environment Institute www.sei.se
University of Leeds – Department of Colour and Polymer Chemistry www.colour.leeds.ac.uk
Donor and Supporting Organisations
Department for International Development (DFID) www.dfid.gov.uk
World Bank www.worldbank.org
Bangladesh Institute for Development Studies www.bids-bd.org
ITDG Technical Briefs answers.practicalaction.org
UN Sustainable Development Networking Programme: Bangladesh www.sdnbd.org/links.htm
Relevant Hands On case studies
Private Eye – England