Experiment of Polyester Wastewater Treatment by Aerobic Membrane Bioreactor and an Engineering Application

Abstract

A pilot study was carried out to evaluate the application of aerobic submerged MBR in treating polyester wastewater and a full scale system in which MBR was adopted as the key aspect was put forward to treat the polyester wastewater of Zhuhai Yuhua Polyester co., Ltd., China. The pilot study revealed that HRT could be affected by the influent COD, and a HRT larger than 36h was proposed for treating polyester wastewater by MBR. Volumetric loading rate and sludge loading rate ranged in 0.7-2.0 kgCOD/m3•d and 0.09~0.24 kgCOD/ kgMLSS•d respectively were of small influence on the COD removal. DO in the range of 2.5-4.0 mg/L seemed to be optimal for avoiding limitations due to oxygen concentration and creating an effective turbulence. The modified full scale system which includes anaerobic digesting tank and MBR followed by a stabilization pond was verified to be effective to treat the polyester wastewater in the latest two years. The results illustrated that the effluent water quality could meet the discharge limits of water pollutants (DB 44/26-2001) which was established in Guangdong, China. Observed sludge yield of the system fluctuated between 0.10-0.18 gMLSS/gCOD and averaged at 0.137 gMLSS/gCOD. The membrane permeate at around 10 L/m2h, TMP of less than 0.7bar, and total mixed liquor suspended solids (MLSS) between 6-7g/L were suitable to operate the MBR.