Prediction of Chemical Oxygen Demand from Turbidity Measurement of Tannery Effluents: An Empirical Relation

Abstract

A linear relation form of chemical oxygen demand (COD) [COD = a * (Turbidity) + b] is being proposed to predict the values of chemical oxygen demand as a function of turbidity for the tannery effluents. By fitting this relation to the available data, the values of the empirical constants are found to be a as 5.96 and b as 670.23, when chemical oxygen demand and turbidity are expressed as mg L^-1 of oxygen and nephelometric turbidity unit (NTU), respectively. The observed chemical oxygen demand of effluent samples collected from different tannery industries are compared statistically with predicted values and the proposed empirical relation shows fairly good agreement.