Chemical and Biochemical Characteristics of Waste Stabilization Ponds Effluent for Unrestricted Irrigation

This research investigation was aimed at demonstrating the technical feasibility of waste stabilization ponds performance for unrestricted irrigation. A pilot plant was constructed at the Karachi University Campus for the treatment of domestic waste water. An intensive programme was followed for fourteen months for evaluating ponds performance efficiency with respect to National Environmental Quality Standards (NEQS) and the potential of pond effluent for unrestricted irrigation, The algal bacterial symbiotic system performed satisfactorily and provided effluent characteristics well within the permissible limit compared to NEQS The Study also demonstrated that high BOD(5) loading of 500 kg/ha d was possible without deteriorating the ponds performance. It was particularly observed that the wind velocity had a pronounced effect on the overall performance of the pond system. The study proves that Such system of waste water treatment is strongly feasible for this region where the scarcity of fresh water is increasing at an alarming rate.