Ensuring effluent treatment plants for industries releasing waste
Saturday, 3 July 2010
M S Siddiqui
Chemicals are widely used in production of consumer goods including paper and pulp mills, chemical industry, textile plants, leather industry etc. Bangladesh has a large number of such industries, which have high potential to release dioxins. An estimated 144.340gTEQ/a of dioxins is released. Going by the industry-wise contribution, it is 2.52 gTEQ/a by paper and pulp, 23.58 gTEQ/a by the chemicals industry, 50.85 gTEQ/a by textile plants and 67.38 gTEQ/a by leather plants.
Waste disposals include landfills and waste dumps, sewage and sewage treatment, waste disposal in water bodies and disposal of waste oil. The way in which the waste is handled and disposed off can effect the formation and release of dioxins. Landfill and waste dumps are a common practice in Bangladesh. These cause leachate and contaminate the soil and water.
Bangladesh and other developing countries have been affected by environmental pollution caused by rapid industrialisation in developed countries. Industrialised countries have invested heavily in carbon-intensive technologies, such as coal-fired power plants, massive road systems, and electrical grids. Annual CO2 emission per person from the burning of oil, natural gas and coal in 2003 in the United , Russia, UK, Japan, China, Brazil, India, Senegal and Bangladesh were 20 tonnes, 11.2 tonnes, 9.5 tonnes, 9.4 tonnes, 2.7 tonnes, 2.0 tonnes 1.0 tonne, 0.5 tonnes and 0.2 tonnes respectively.
Since the beginning of the industrial revolution the atmospheric concentration of carbon dioxide has increased exponentially from about 280 parts per million in 1800 to over 380ppm in 2006. The concentration of carbon dioxide and methane in the atmosphere are now at their highest levels in 650,000 years. The level of carbon dioxide in the atmosphere is very closely linked to global temperature. The IPCC has projected that by 2100 atmospheric concentration of carbon dioxide could reach between 540ppm and 970ppm and that, as a result, global surface temperature could rise by between 1.4 degrees C and 5.8 degrees C. Climate change threatens the basic elements of life for people around the world. On current trends, average global temperatures could rise by 2-3°C within the next fifty years or so, leading to many severe impacts, often mediated by water, including more frequent droughts and floods.
According to IPCC in their recently published Fourth Assessment, the following changes have been observed in climate trends, variability and extreme events:
* In Bangladesh, average temperature has registered an increasing trend of about 1°C in May and 0.5°C in November during the 14 year period from 1985 to 1998.
o The annual mean rainfall exhibits increasing trends in Bangladesh. Decadal rain anomalies are above long term averages since 1960s.
o Serious and recurring floods have taken place during 2002, 2003, and 2004. Cyclones originating from the Bay of Bengal have been noted to decrease
since 1970 but the intensity has increased.
o Frequency of monsoon depressions and cyclones formation in Bay of Bengal has increased.
o Water shortages have been attributed to rapid urbanization and industrialization, population growth and inefficient water use, which are aggravated by changing climate and its adverse impacts on demand, supply and water quality.
o Salt water from the Bay of Bengal is reported to have penetrated into 100 km or more inland along tributary channels during the dry season.
o The precipitation decline and drought have resulted in the drying up of wetlands and severe degradation of ecosystems.
A major concern for Bangladesh are climate change victims who are increasing in number every day and seeking refuge due to loss of their homes, land, settlement to river erosion, coastal erosion, and permanent inundation. It is alarming that there is no obligation for states to recognize the internal and external displacement of people due to climate change or other environmental factors. There are four major types of victims of climate change, which can be highlighted. They are victims of riverbank erosion, coastal erosion, permanent inundation and sea level rise.
The number of families and villages who lose their homes permanently to rivers every year are perhaps one of the highest in Bangladesh. It has been reported that many of the slum dwellers in the metropolitan areas are the victims of riverbank erosion. In the decade of 1982 - 1992, over 106,000 hectares of land has been eroded along banks of the three major rivers of Bangladesh (the Ganges, the Brahmaputra and the Meghna) against an accretion of only 19,000 hectares. About 350,000 people were displaced due to riverbank erosion in that decade, who suffered severe economic and social consequences. Substantial numbers are also being displaced from coastal islands, chars, and along the coastline as their settlements are destroyed due to frequent and intense storm surge and tidal bores.
The policies and legislation in Bangladesh to protect water from industrial and other effluent is well constructed and comprehensive.
Conservation rules, and National Water Policy have adequate clauses relating to industrial pollution. This includes water quality protection, effluent discharge monitoring, zoning regulations for new industries and strengthening of the regulatory system for agrochemical pollution control. The two exceptions to this are concerns over the failure to establish the Wetland Policy, which after several years has still not been put before parliament, and the apparent overlap in mandates of the MOEF and The Water Resources Planning Organization (WARPO) (WARPO) and National Water Resources Council (NWRC) in developing and implementing policies regarding water resources development and management. However, such concerns are insignificant in comparison to those in relation to the institutional capacity and capability to enforce them.
In Bangladesh, the concept of effluent water treatment and waste management is relatively new, especially in the textile sector. A common problem is uncertainty as to how exactly to operate the plant post-commissioning of the ETP.
The efficiency and effectiveness of an effluent treatment plant (ETP) depends on several factors. The production capacity of the unit, the volume of effluent produced and over what timeframe and characteristics of effluent are all important factors in ETP design, construction and management. The first steps in ETP construction is to specify the requirements of an ETP with respect to quality of final treated effluent required and to determine the volume and quality of the effluent to be treated. The effluent discharged from the different stages of production process contains different types of chemicals. To obtain the composite value of pollution parameters from all those stages two different approaches were used.
During the project period the project found that most of the textile industry owners are facing problems because of their limited knowledge of effluent treatment processes and ETPs. The project worked with several factories to provide information on ETP design and management.
In the textile dyeing sequence there are several different distinct stages that might be scouring, neutralization, dyeing, acid wash, softening and rinsing. Wastewater discharged from different stages has different characteristics. Some streams are alkaline in nature, some are acidic and some are almost neutral.
According to the characteristics of different waste-stream the textile effluent can be classified into two types: highly polluted streams and less polluted streams. If wastewater from different stages can be segregated in terms of highly polluted and less polluted, then these two streams can be treated according to their characteristics, and that can lower the running cost of the ETP. For example, wastewaters with lower chemical oxygen demand (COD) and biochemical oxygen demand (BOD) can be treated only biologically; on the other hand highly polluted waste-streams are to be treated both physico-chemically and biologically. As example, effluents with high colour and suspended solids need physico-chemical treatment and those with low concentrations of soluble pollutants may only need biological treatment.
These steps are recommended to be treated both physico-chemically and biologically. The rest of the steps are less polluting with relatively low BOD, COD, suspended solids, colour, and a low COD/BOD ratio (suggesting they are relatively degradable) and it should be possible to treat these solely by biological methods at controlled pH (if required).
The tannery owners said they demanded Tk 2.50 billon in compensation for the relocation, but the government has not taken any decision in this regard. It is unlikely to make full-scale relocation by 2010 as it takes at least two and a half years to complete the work on the Common Effluent Treatment Plant (CETP).
There are hundreds of wastewater treatment technologies depending on the type of wastewater to be treated. Some of the most used treatment technologies in our country are based on conventional chemical treatments, which are less effective. But we have to look for a cost-effective wastewater treatment technology. Such wastewater treatment technology can be Ultraviolet Radiation Treatment of wastewater or electron beam radiation treatment. This has been proved to be very cost-effective in treating industrial wastewater.
Feasibility of a radiation induced wastewater treatment plant
Radiation induced wastewater treatment can be potentially beneficial in treating industrial and municipal wastewater in Dhaka city. This decontaminated waster contains nitrogen compound and could be used for irrigation. A laboratory scale plant has been developed in the Radiation and Polymer Chemistry Laboratory of Bangladesh Atomic Energy Commission to treat the textile effluent. The result was promising. Here we can propose wastewater treatment, which involve the integration of biological treatment of the wastewater, with electron beam accelerator.
Radiation treatment technology represents a viable solution to the problem of wastewater treatment. Several countries have already taken the initiative of implementing electron beam in the irradiation of wastewater. Scientists of Bangladesh Atomic Energy Commission are able to design and establish such wastewater treatment plant in our country to save Dhaka city from wastewater pollution.
Two central effluent treatment plants (ETPs) are expected to go into operation next year in the export-processing zones in Dhaka and Chittagong to better manage toxic waste water, officials have said.
Factories in the EPZs will get the facilities to share the centrally installed ETPs for treating waste water before discharge.
The projects will be implemented under a private-public partnership, where Singapore-based D-Water CETP Eco System BD Ltd got the contract for constructing the unique plant in the DEPZ. Chittagong Waste Water Treatment Plants Ltd. will install another in the CEPZ.
The Bangladesh Export Processing Zones Authority (Bepza) in partnership with the Bangladesh Investment Climate Fund (BICF) has initiated the schemes.
The fund, with contribution from British aid agency DFID and the European Commission (EC), is managed by the World Bank's lending arm International Finance Corporation (IFC). (20)
On June 23, the High Court ordered installation of ETPs for all industries, including the tanneries, by June 2010, following a petition by environmental and human rights groups.
The court also directed the industries secretary to ensure that no new industry is set up without effective steps to check environmental pollution.
The central bank in its recent refinance scheme of Tk 2.0 billion included low-interest loans for setting up ETPs.
Wastewater treatment technologies have improved significantly. In developed countries, wastewater is treated as a source of energy. Waste-to-energy has become a sustainable point of view towards wastewater treatment. The more the water is organic, the more energy it contains. So, we can actually think of wastewater as a source of energy.
The writer is a part-time teacher of Leading University. He can be reached at e-mail: shah@banglachemical.com
Chemicals are widely used in production of consumer goods including paper and pulp mills, chemical industry, textile plants, leather industry etc. Bangladesh has a large number of such industries, which have high potential to release dioxins. An estimated 144.340gTEQ/a of dioxins is released. Going by the industry-wise contribution, it is 2.52 gTEQ/a by paper and pulp, 23.58 gTEQ/a by the chemicals industry, 50.85 gTEQ/a by textile plants and 67.38 gTEQ/a by leather plants.
Waste disposals include landfills and waste dumps, sewage and sewage treatment, waste disposal in water bodies and disposal of waste oil. The way in which the waste is handled and disposed off can effect the formation and release of dioxins. Landfill and waste dumps are a common practice in Bangladesh. These cause leachate and contaminate the soil and water.
Bangladesh and other developing countries have been affected by environmental pollution caused by rapid industrialisation in developed countries. Industrialised countries have invested heavily in carbon-intensive technologies, such as coal-fired power plants, massive road systems, and electrical grids. Annual CO2 emission per person from the burning of oil, natural gas and coal in 2003 in the United , Russia, UK, Japan, China, Brazil, India, Senegal and Bangladesh were 20 tonnes, 11.2 tonnes, 9.5 tonnes, 9.4 tonnes, 2.7 tonnes, 2.0 tonnes 1.0 tonne, 0.5 tonnes and 0.2 tonnes respectively.
Since the beginning of the industrial revolution the atmospheric concentration of carbon dioxide has increased exponentially from about 280 parts per million in 1800 to over 380ppm in 2006. The concentration of carbon dioxide and methane in the atmosphere are now at their highest levels in 650,000 years. The level of carbon dioxide in the atmosphere is very closely linked to global temperature. The IPCC has projected that by 2100 atmospheric concentration of carbon dioxide could reach between 540ppm and 970ppm and that, as a result, global surface temperature could rise by between 1.4 degrees C and 5.8 degrees C. Climate change threatens the basic elements of life for people around the world. On current trends, average global temperatures could rise by 2-3°C within the next fifty years or so, leading to many severe impacts, often mediated by water, including more frequent droughts and floods.
According to IPCC in their recently published Fourth Assessment, the following changes have been observed in climate trends, variability and extreme events:
* In Bangladesh, average temperature has registered an increasing trend of about 1°C in May and 0.5°C in November during the 14 year period from 1985 to 1998.
o The annual mean rainfall exhibits increasing trends in Bangladesh. Decadal rain anomalies are above long term averages since 1960s.
o Serious and recurring floods have taken place during 2002, 2003, and 2004. Cyclones originating from the Bay of Bengal have been noted to decrease
since 1970 but the intensity has increased.
o Frequency of monsoon depressions and cyclones formation in Bay of Bengal has increased.
o Water shortages have been attributed to rapid urbanization and industrialization, population growth and inefficient water use, which are aggravated by changing climate and its adverse impacts on demand, supply and water quality.
o Salt water from the Bay of Bengal is reported to have penetrated into 100 km or more inland along tributary channels during the dry season.
o The precipitation decline and drought have resulted in the drying up of wetlands and severe degradation of ecosystems.
A major concern for Bangladesh are climate change victims who are increasing in number every day and seeking refuge due to loss of their homes, land, settlement to river erosion, coastal erosion, and permanent inundation. It is alarming that there is no obligation for states to recognize the internal and external displacement of people due to climate change or other environmental factors. There are four major types of victims of climate change, which can be highlighted. They are victims of riverbank erosion, coastal erosion, permanent inundation and sea level rise.
The number of families and villages who lose their homes permanently to rivers every year are perhaps one of the highest in Bangladesh. It has been reported that many of the slum dwellers in the metropolitan areas are the victims of riverbank erosion. In the decade of 1982 - 1992, over 106,000 hectares of land has been eroded along banks of the three major rivers of Bangladesh (the Ganges, the Brahmaputra and the Meghna) against an accretion of only 19,000 hectares. About 350,000 people were displaced due to riverbank erosion in that decade, who suffered severe economic and social consequences. Substantial numbers are also being displaced from coastal islands, chars, and along the coastline as their settlements are destroyed due to frequent and intense storm surge and tidal bores.
The policies and legislation in Bangladesh to protect water from industrial and other effluent is well constructed and comprehensive.
Conservation rules, and National Water Policy have adequate clauses relating to industrial pollution. This includes water quality protection, effluent discharge monitoring, zoning regulations for new industries and strengthening of the regulatory system for agrochemical pollution control. The two exceptions to this are concerns over the failure to establish the Wetland Policy, which after several years has still not been put before parliament, and the apparent overlap in mandates of the MOEF and The Water Resources Planning Organization (WARPO) (WARPO) and National Water Resources Council (NWRC) in developing and implementing policies regarding water resources development and management. However, such concerns are insignificant in comparison to those in relation to the institutional capacity and capability to enforce them.
In Bangladesh, the concept of effluent water treatment and waste management is relatively new, especially in the textile sector. A common problem is uncertainty as to how exactly to operate the plant post-commissioning of the ETP.
The efficiency and effectiveness of an effluent treatment plant (ETP) depends on several factors. The production capacity of the unit, the volume of effluent produced and over what timeframe and characteristics of effluent are all important factors in ETP design, construction and management. The first steps in ETP construction is to specify the requirements of an ETP with respect to quality of final treated effluent required and to determine the volume and quality of the effluent to be treated. The effluent discharged from the different stages of production process contains different types of chemicals. To obtain the composite value of pollution parameters from all those stages two different approaches were used.
During the project period the project found that most of the textile industry owners are facing problems because of their limited knowledge of effluent treatment processes and ETPs. The project worked with several factories to provide information on ETP design and management.
In the textile dyeing sequence there are several different distinct stages that might be scouring, neutralization, dyeing, acid wash, softening and rinsing. Wastewater discharged from different stages has different characteristics. Some streams are alkaline in nature, some are acidic and some are almost neutral.
According to the characteristics of different waste-stream the textile effluent can be classified into two types: highly polluted streams and less polluted streams. If wastewater from different stages can be segregated in terms of highly polluted and less polluted, then these two streams can be treated according to their characteristics, and that can lower the running cost of the ETP. For example, wastewaters with lower chemical oxygen demand (COD) and biochemical oxygen demand (BOD) can be treated only biologically; on the other hand highly polluted waste-streams are to be treated both physico-chemically and biologically. As example, effluents with high colour and suspended solids need physico-chemical treatment and those with low concentrations of soluble pollutants may only need biological treatment.
These steps are recommended to be treated both physico-chemically and biologically. The rest of the steps are less polluting with relatively low BOD, COD, suspended solids, colour, and a low COD/BOD ratio (suggesting they are relatively degradable) and it should be possible to treat these solely by biological methods at controlled pH (if required).
The tannery owners said they demanded Tk 2.50 billon in compensation for the relocation, but the government has not taken any decision in this regard. It is unlikely to make full-scale relocation by 2010 as it takes at least two and a half years to complete the work on the Common Effluent Treatment Plant (CETP).
There are hundreds of wastewater treatment technologies depending on the type of wastewater to be treated. Some of the most used treatment technologies in our country are based on conventional chemical treatments, which are less effective. But we have to look for a cost-effective wastewater treatment technology. Such wastewater treatment technology can be Ultraviolet Radiation Treatment of wastewater or electron beam radiation treatment. This has been proved to be very cost-effective in treating industrial wastewater.
Feasibility of a radiation induced wastewater treatment plant
Radiation induced wastewater treatment can be potentially beneficial in treating industrial and municipal wastewater in Dhaka city. This decontaminated waster contains nitrogen compound and could be used for irrigation. A laboratory scale plant has been developed in the Radiation and Polymer Chemistry Laboratory of Bangladesh Atomic Energy Commission to treat the textile effluent. The result was promising. Here we can propose wastewater treatment, which involve the integration of biological treatment of the wastewater, with electron beam accelerator.
Radiation treatment technology represents a viable solution to the problem of wastewater treatment. Several countries have already taken the initiative of implementing electron beam in the irradiation of wastewater. Scientists of Bangladesh Atomic Energy Commission are able to design and establish such wastewater treatment plant in our country to save Dhaka city from wastewater pollution.
Two central effluent treatment plants (ETPs) are expected to go into operation next year in the export-processing zones in Dhaka and Chittagong to better manage toxic waste water, officials have said.
Factories in the EPZs will get the facilities to share the centrally installed ETPs for treating waste water before discharge.
The projects will be implemented under a private-public partnership, where Singapore-based D-Water CETP Eco System BD Ltd got the contract for constructing the unique plant in the DEPZ. Chittagong Waste Water Treatment Plants Ltd. will install another in the CEPZ.
The Bangladesh Export Processing Zones Authority (Bepza) in partnership with the Bangladesh Investment Climate Fund (BICF) has initiated the schemes.
The fund, with contribution from British aid agency DFID and the European Commission (EC), is managed by the World Bank's lending arm International Finance Corporation (IFC). (20)
On June 23, the High Court ordered installation of ETPs for all industries, including the tanneries, by June 2010, following a petition by environmental and human rights groups.
The court also directed the industries secretary to ensure that no new industry is set up without effective steps to check environmental pollution.
The central bank in its recent refinance scheme of Tk 2.0 billion included low-interest loans for setting up ETPs.
Wastewater treatment technologies have improved significantly. In developed countries, wastewater is treated as a source of energy. Waste-to-energy has become a sustainable point of view towards wastewater treatment. The more the water is organic, the more energy it contains. So, we can actually think of wastewater as a source of energy.
The writer is a part-time teacher of Leading University. He can be reached at e-mail: shah@banglachemical.com