막분리 활성슬러지법에서 초음파의 영향

Abstract

The Membrane bioreactor(MBR) has now become an attractive option for the treatment of waste waters, as evidenced by their constantly rising numbers and capacity. It combines activated sludge treatment with a membrane separation process. For the sewage treatment, MBR is excellent for the treatment of COD(Chemical oxygen demand), SS(Suspended solid) and microorganisms. But, sludge concentration is increased in a bioreactor over a long operation time. When sludge concentration is increased, membrane fouling occurs. This study focused on the evaluation of performance of the MBR combined with a ultrasonic sysytem, ultrasonic system for the advanced treatment of sewage in terms of COD, SS and . The laboratory scale with capacity of 28.8 had operated for fifty days with two operational patterns, namely Mode1(non-Ultrasonic) and Mode2(combined ultrasonic). Mode1's membrane fouling occurred, because Mixed Liquor Suspended Solid(MLSS) is increased. So membrane's surface scrubbed. Due to the ultrasonic operate that Mode2's MLSS is decreased. So membrane contamination slacken. Also the COD's processing ratio of Mode1 and Mode2 were excellent over 95%. However, the COD was increased 2.8 by ultrasonic treatment. MBR needs an aerobic process and anaerobic process for phosphorus treatment. In this study, Mode1's phosphorus processing ratio was 38%, because only aerobic process was performed. Mode2's phosphorus was increased by ultrasonic treatment, because ultrasonic splits sludg. So phosphorus was dissolved in sludge. This study demonstrates that the combination of MBR and ultrasonic process is an excellent technology as membrane fouling and COD treatment. But, this process needs phosphorus treatment process.