Physico-Chemical Characterization of Dry-Weather-Flow Wastewater and Assessment of Treatment Plants in Nitte and Environs, India

Abstract

The effective treatment of a given wastewater depends largely on its characteristics. Physico-chemical parameters constitute indispensible analytes in wastewater. In two pre-monsoon months when there was Dry-Weather-Flow (DWF), this study characterized the wastewater in Nitte, India based on the physical and chemical properties. It also assessed efficiency of its domestic and industrial Wastewater Treatment Plants. Fourteen samples were collected from domestic and industrial wastewater in the environment, sources of which include:hostels, laundry, mechanical and auto-workshop effluent, foundry, WTP influent, and landfill leachates. Parameters measured are: colour, odour, temperature, turbidity, pH, electrical conductivity, chloride, nitrate, sulphate, phosphate, Chemical Oxygen Demand, Copper, Lead, Magnesium, Chromium, Nickel, Zinc, Manganese, Cadmium and Phenols, using Standard Methods. Findings show that the main physico-chemical parameters that are of pollution concern in the domestic wastewater of the study area include conductivity, chloride, COD, phenols, phosphate, Cu, Pb and Mg. Pollutants in the industrial wastewater encompass Cr and Zn in addition to those of domestic wastewater, while Cd is a key pollutant in leachates aside those identified in domestic and industrial wastewater samples. Domestic WTP is more suitable in remediating turbidity, sulphate, nitrate and phosphate unlike industrial one that is more efficient in treating chloride, Ni and Zn. Both reduced COD, with domestic WTP being of better performance but also not to a pollution-free concentration level. Both WTPs are found to be incapable of treating phenols in the samples.Further treatment methods like bioremediation, ion-exchange and adsorption are therefore recommended in addition to the existing WTPs in the study area.

Keywords: Pollution, Remediation, Trace metals, Wastewater, Concentration, Pollution,