Assessing the water quality of canals in Dhaka city, Bangladesh

Abstract

Environmental degradation related to hazardous pollutants from economic activity became a major concern in many rapidly developing mega cities of the global South. In this study, the level of selected parameters (pH, TDS, TSS, TS, Alkalinity, Hardness, DO, BOD, COD, Na, Fe, Cr, Ni, Cd, Pb, Cl-, Cu, and SO4-2, NO3- and PO4-2) were measured to find water quality of canals in Dhaka City, Bangladesh. Samples were collected from 17 different canals in and around Dhaka City Corporation (DCC) area. Principal Component Analysis (PCA) and Cluster Analysis (CA) were used to assess the metal contamination of chemical parameters in the canals. Mean, Median, Minimum, Maximum and Standard Deviation were used to assess the variation of results of samples of canals. The analysis shows that in most of the samples physical and chemical parameters of hazardous materials were found. SO4-2, Cr, Cu and Pb were present as major pollutants with high concentration level, while Cl-, Cd, Na and Fe emerged as minor pollutants. Further, TDS, Alkalinity and Hardness were found to increase alarmingly while BOD levels were found below the acceptable limit and rests were unchanged. Finally, data for the presence of metal in the canal sediments shows Cr and Pb levels were higher than the recommended sediment quality by both guidelines of Department of Environment (DoE), Bangladesh and the United States Environment Protection Agency (USEPA). From overall findings it is evident that sustaining environmental quality needs special attention to check hazardous pollutants in the water of canals in Dhaka.