Water quality assessment in terms of water quality index: a case study of the Halda River, Chittagong

Abstract

Water quality index is like a grade which represents overall water quality of a location and time based on several water quality parameters. To achieve the aim, the Weighed Arithmetic Index method was applied on the analytical results of the parameters to obtain a single value that was used to rank the river at each of the sampling station. An exertion has been made to develop water quality index (WQI), using eight physicochemical parameters of water including pH, dissolved oxygen, biochemical oxygen demand, electrical conductivity, nitrate, chloride, turbidity, total dissolved solid(TDS) measured at five different location along the Halda river. Halda river is the one and only carp breeding ground in Bangladesh. It is also one of the major sources of water supply in Chittagong city . The WQI of Halda River during Monsoon period found (15 – 38.5) and during Non-Monsoon period (6 – 13). Which shows some interesting result, generally the water quality in Monsoon period is good but here is not good rather than Non-Monsoon period. It was observed from the study that the effect of industrial waste disposal without any treatment and human activities in the river was severe on most of the parameters.