Efficiency of polyethene non-woven fibre filter for treating institutional waste water by membrane bio reactor process

Abstract

Treatment of waste water involves a variety of Advanced Oxidation Process. The most advanced one is Membrane Bio Reactor (MBR). The unique features of MBR are higher order MLSS in the range of 12,000 mg/l and reduces the sludge production. This process is efficient in removing Total Solids in waste water. Due to the fact that the membrane being too costly, an alternative approach was taken which featured Polyethylene Non-woven Fibre Filter that gave promising results. A laboratory scale Membrane reactor is fabricated for treatment of Institutional Waste water. A small scale reactor is formed by scaling with the treatment plant of capacity 3MLD in the ratio 1:4000. The process involves combination of activated sludge process and membrane filtration. The waste water is pumped to the aeration tank by peristaltic pump from the collection tank. The water is filled in the tank by leaving the freeboard space. The air is supplied by reverse process of peristaltic pump for 2.5 hrs (HRT). After the aeration process, the water is passed over the membrane for filtration. The organic impurities which are present in the membrane after treatment are returned to the aeration tank for the next process (3hrs HRT).The process is continued until the maximum removal efficiency is achieved by varying the run time. The BOD and Turbidity is tested for the treated water at various runtime The Hydraulic Retention Time (HRT) is varied in the range 2.5 - 6 hrs. The maximum BOD removal efficiency obtained was 98% and turbidity removal efficiency was 97% in the 6 hrs HRT. The MBR system offers many benefits, such as higher MLSS rate, exclusion of sedimentation unit, less sludge production compared to Activated Sludge Process. Various studies of MBR technology has compared with conventional activated Sludge process in terms of removal of pollutants from waste water. The drawback of MBR process is high installation and operation cost. Thus an alternative approach of replacing the membrane by Polyethylene non woven fibre membrane is used which gave the promising results.