무산소/호기(A/O)형 MBR-RO공정에 의한 폐수처리에 관한 연구

Abstract

A membrane bioreactor (MBR) is an effective tool for wastewater recycling and treatment. MBR process has several advantages over conventional activated sludge process (ASP); reliability, compactness, and quality of water. The resulting high-quality and disinfected effluent suggests that MBR process can suitable for the reuse and recycling of wastewater. An anoxic/oxic (A/O) MBR was applied to simultaneous removal of carbon and nitrogen components in sewage. In this study, at first, the efficiency of submerged MBR was investigated using hollow fiber microfiltration membrane with a constant flux of 10.2 L/m2·h at different solids retention time (SRT). Results show that protein/carbohydrate ratio increased and total extracellular polymeric substances (EPS) remained constant with SRT. Inorganic nitrogen removal efficiency increased with SRT due to a higher biomass concentration while phosphate was hardly removed. The removal efficiency of chemical oxygen demand (COD) was considerably high (over 80%) throughout the experiment. Secondly, a lab-scale A/O MBR with reverse osmosis (RO) membrane was applied to treat the municipal wastewater. The A/O MBR-RO process is better than the conventional ASP in terms of consistent product quality including COD, inorganic nitrogen and total nitrogen. For the treatment of organic materials in municipal wastewater, the A/O MBR-RO process superior to the ASP. However, both processes showed little efficiency of phosphate removal because dissolved oxygen (DO) concentration in A/O MBR process was too high.