ANAEROBICALLY TREATED EFFLUENTS: B.O.D. EVALUATION

Abstract

Quantity and quality of wastewater from industries and domestic wastes vary, depending on the product and process selected. Biological treatment methods are preferred to physico-chemical methods for safe disposal due to their cost effectiveness and efficient treatability of wastes. Anaerobic digestion of the organic waste is known to reduce the pollution load and simultaneously produce biogas, which is a valuable byproduct. Wastes with high BOD: COD ratios are studied in a batch anaerobic scale study with acclimatized seed sludge. In the present study an attempt has been made to evaluate the efficiency of anaerobic treatment of batch type anaerobic waste for synthetic wastewater. Continuous monitoring of parameters likes BOD, COD, pH, ORP were carried out to evaluate the performance of anaerobic treatment method. The study is carried out for five different organic synthetic waste ranging from 385 to 900 mg/L as COD. In the study pH was found in the range of 6.8 to 8.8. O.R.P was found to vary in the range of 130 to —150. Anaerobic condition was generated with the help of Na2SO3 in varying proportions. . In the present study ORP is used as a major tool to study the anaerobic treatment phenomenon, From the present study one can find the change in the available D.O. (Oxygen availability) of the sewage at any particular stage of treatment. The studies revealed that BOD increases with the decrease in ORP. It signifies that a substrate BOD can be decreased to a satisfactory level of effluent discharge to the streams or any natural system. In the present study ORP is used as a major tool to study the anaerobic treatment phenomena.