An Evaluation of the Effects of Lead on the Biodegradation of Organic Wastes

Abstract

This study constitutes an additional step in limiting the concentration of lead in wastewater effluent from waste stabilization ponds. The effects of lead on the biodegradation rate of organic wastes were investigated at lead concentrations of 0, 5, 10, 20, 30, 40, 50, 75, 100, 125, 150, 200mg/l in batch cultures. Several runs were in order to determine temperature effects. A model was proposed to predict deoxygenation rate for different concentrations of lead at various temperatures. The model parameters  namely the ultimate BOD, reaction rate constant and lag time were optimized by ordinary least squares (OLS) using the modified Gompertz model. The ultimate BOD and lag time increased as lead concentration was increased. However the deoxygenation rate decreased as lead concentration increased. The deoxygenation rate and ultimate BOD had maximum values at optimum temperature range of 30.15-33.50 ^oC.