Material balance approach to measure water pollution impact of industrial development in Bangladesh

Abstract

The rapidly developing economy of Bangladesh is mainly driven by its uprising industries over the past few decades. Among these industries Ready Made Garments (RMG) and leather industries are the largest export sectors. In Bangladesh, RMG and leather industries currently have an export value of nearly 28 billion USD and 1 billion USD per year respectively which contributes about 85% of the total export earnings. It is projected that the annual RMG and leather export value will be about 50 billion USD and 5 billion USD respectively by 2021. However, this rapid growth of RMG and leather sector is associated with different environmental issues mostly caused by wastewater generated by textile and tannery industries. Both of these industries consume high volume of water per unit to process fabric and raw salted hide, which may cause depletion of groundwater level at a high rate. Besides, in many cases effluents from these industries are discharged to river or wetlands without proper treatment. Improving conventional technology and adapting cleaner production options may reduce water consumption and effluent volume. However, additional investment, and lack of technological knowhow and awareness are the limiting factors of adapting cleaner production options. To take effective measures for future improvement it is important to develop a nationwide wastewater impact tracking system. In this study, a material balance approach is applied to predict the trend of pollution loads (2011-2021) associated with textile dyeing and tannery industries of Bangladesh. It is estimated that in 2016, textile industries produced about 1.80 million metric tons of fabrics which generated around 217 million m3 of wastewater and leather industries produced 300 million square feet of leather which generated around 12 million m3 of wastewater with a wide range of pollution characteristics in Bangladesh. It is projected that around 403 million m3 of wastewater will be produced in 2021 by textile dyeing and tannery industries using conventional dyeing practices. Gradual adaptation of improved technology and cleaner production options may reduce wastewater volume around 23% for textile process and 50% for leather process by 2021. This projection will help policy makers to take necessary mitigation measures for treatment and pollution management. This analysis will also provide a baseline scenario and open new opportunities for engineers and environmentalists to develop innovative technologies for textile dyeing, leather tanning and effluent treatment.