Abstract

The aim of this study is to assess and report trace metal contamination of water samples of Balu River, collected from four stations which was sampled every three months covering the upstream and downstream sites of major industrial area of Tajgaon of Dhaka city. The dissolve concentration Iron, Lead, Cadmium, Manganese, Cobalt, Nickel, Chromium, Zinc, Copper of water samples was determined by atomic absorption spectrometry and were found to range from 1.79 to 50.15 mg/L, <17.96 to 28.25 μg/L, <3.00 to 3.30 μg/L, 28.28 to 730.79 μg/L, <4.05 to 53.92 μg/L, <10.66 to 19.07 μg/L, <4.05 to 8.44 μg/L, 8.39 to 76.86 μg/L, and 3.81 to 19.99 μg/L. The observed concentrations of the metals varied between sampling sites and also in different season. Metal concentration was higher in the dry (March) than rainy season in most cases. The pollution level is within the limit of Bangladesh standard and below the Environmental Protection Agency and World Health Organization standard except Iron. From this study, it is clear that the water of this river is not an immediate threat to ecosystem but most of the parameters are higher than other rivers of Bangladesh and in future may cause a threat to ecosystem.

 Key words: Trace metal, atomic absorption spectrophotometer, concentration.