Comparative studies of microbial efficiency based on different dissolved oxygen (DO) concentration in the tannery effluent

Abstract

A Effluent samples were collected from a tannery in Ambur, Vellore Dist, Tamil Nadu, India. The physiochemical parameters of the effluent viz, colour, odour, pH, Electrical conductivity, TSS, TDS, BOD, COD, total hardness, calcium hardness magnesium hardness, chloride, sulphate and total chromium were determined. The results revealed that almost all the parameters of tannery Effluent were found to be high and exceeding the (CPCB-Central Pollution Control Board) limits. This project work has been focused on the study of enhanced primary treatment of tannery effluent by coagulants which includes analysis of physico-chemical parameters of tannery effluent as well as the treatment efficiency of alum, ferric sulphate and their combination (alum+ferric sulphate). Sample collection and analysis were performed using standard methods for the examination of water and waste water. Tannery effluent has been treated with the coagulants. The influences of pH and coagulant dosages were also studied. Conditions were optimized according to the pollutant removal efficiencies measured in terms of reduction in concentration of total suspended solid (TSS), biological oxygen demand (BOD3), chemical oxygen demand (COD) and Chromium (Cr). The reduced concentrations of pollutants have been analyzed with industrial effluent discharge standards to determine the efficiency of coagulants in enhanced primary treatment of tannery effluent.