Industrialisation Scenario at Sreepur of Gazipur, Bangladesh and Physico-chemical Properties of Wastewater Discharged from Industries

Abstract

This study was conducted to explore the present trend and pattern of industrial growth with spatial distribution of industries and seasonal extent of physicochemical characteristics of wastewater at Sreepur of Gazipur, Bangladesh. The wastewater samples were collected from 5 locations in three seasons viz. pre-monsoon, monsoon and dry season. A total of 120 medium to large industries were surveyed, among those 52 were in red category, 53 were in orange-B category, 13 were in orange-A and only 2 were in green category. In 1995, there were only three industries, which gradually increased to a total of 29 in 2005. Among them, 11 were in red category and 18 were in orange-B category. But from 2006-2010, a total 59 industries were developed and most of them were in red and orange-B categories. Similarly, during the period of 2011 to March 2013, a total 16 industries were developed, among them 8 industries were in red and 3 were in orange-B category. Major types of wastewater discharging industries were textile, dyeing, washing and printing. Among the surveyed industries about 33% didn’t have any effluent treatment plant (ETP). The mean value of pH, EC, DO, BOD, COD and TDS of wastewater were 7.28, 2.64, 1.62 mg L-1, 82.0 mg L-1, 217.31 mg L-1 and 1380 mg L-1, respectively during pre-monsoon; 6.7, 1.15, trace, 8.0 mg L-1, 152.4 mg L-1 and 539.58 mg L-1, respectively during monsoon and 7.7, 1.82, 0.74 mg L-1, 48.8 mg L-1, 204.8 mg L-1 and 993.6 mg L-1, respectively during dry season. Average DO concentrations in all seasons and sites were significantly low, while BOD and COD contents were higher in pre-monsoon and dry seasons than the DoE permissible limit. The study concluded that the area is now a hub of polluting industries which are mostly liable to pollute the surrounding environment.