Investigation of the impacts of industrial towns on urban rivers through physicochemical analysis of water quality and the water quality index (WQI)

Abstract

The present study was undertaken to assess the pollution status of Erai and Zarpat rivers flowing through industrial Chandrapur City, Maharashtra, India.  The obtained data of physicochemical parameters were processed to calculate Water Quality Index (WQI). The obtained data revealed that the physicochemical parameters such as turbidity (20.2-28.7 NTU), hardness (236-276 mg/l), total dissolved solids (1586-1730 mg/l), nitrates (49-53 mg/l), phosphate (0.7-0.9 mg/l), chemical oxygen demand (53.2-69.2 mg/l) and biochemical oxygen demand (19-22 mg/l) were beyond the permissible  limits of Bureau of Indian Standard (BIS).The concentrations of toxic metals viz. cadmium (0,006-0.008 mg/l), lead (0.03-0.05 mg/l), arsenic (0.0-0.03 mg/l) and molybdenum (0.05-0.07 mg/l) in river water were also recorded higher than permissible limits of BIS. The WQI values of both the rivers at different sampling stations ranged from 144 to 220 indicating poor to very poor water quality. The sources of pollution in both the rivers were disposal of fly ash, mining, disposal of treated and untreated domestic and industrial effluent due to lack of sewage treatment plants (STPs), effluent treatment plant (ETP), and common effluent treatment plant (CETP). Therefore, there is a need of construction of STP, ETP, CETP, proper disposal of fly ash, and desludging of rivers at regular intervals.