PERFORMANCE STUDY FOR TREATMENT OF INSTITUTIONAL WASTEWATER BY ACTIVATED SLUDGE PROCESS

Treatment of waste water involves a variety of methods. Biological treatment using aerobic activated sludge process has been in practice over a century. Conventional Activated Sludge Process (ASP) is the most common and oldest bio treatment process used to treat municipal and industrial wastewater. Typically wastewater after primary treatment i.e. suspended impurities removal is treated in an activated sludge process based biological treatment system comprising aeration tank followed by secondary clarifier. The aeration tank is a completely mixed bioreactor where specific concentration of biomass (measured as mixed liquor suspended solids (MLSS) is maintained along with sufficient dissolved oxygen (DO) concentration (typically 2 mg/l) to effect biodegradation of soluble organic impurities measured as biochemical oxygen demand (BOD 5 days). The Hydraulic Retention Time (HRT) is varied in the range 3 - 8 hrs. The maximum BOD removal efficiency obtained was 93.7% and turbidity removal efficiency was 87.6% in the 8 hrs HRT.