PHOSPHORUS REMOVAL FROM DAIRY WASTEWATER IN BATCH SYSTEMS UNDER SIMULTANEOUS AEROBIC/ANAEROBIC CONDITIONS: APPLICATION OF RESPONSE SURFACE METHODOLOGY

The objective of this paper is simultaneous of aerobic and anaerobic process for phosphorus removal from a dairy wastewater. The system consists of a granular sequencing batch reactor (SBR) working under alternating aerobic/anaerobic conditions. In order to analyze the process, four significant variables viz. MLSS, COD/N ratio, aeration time and cycling time and four dependent parameters as the process responses were studied using a central composite design (CCD) under response surface methodology (RSM). The percentage removal of PO43- and amount of SVI, MLSS, MLVSS, in batch runs were 98.34%, 44.03 ml/g, 5646.97 mg/l and 4435.99 mg/l, respectively. This study shows that the high removal of phosphors from dairy wastewater with microbial granules cultivated under the alternating aerobic–anaerobic conditions has been achieved successfully in batch systems.