Application of Anaerobic Membrane Bioreactor to the Treatment of Low-Strength Municipal Wastewater

Abstract

An anaerobic membrane bioreactor (AnMBR) was employed for the treatment of low-strength municipal wastewater in this study. The membrane filtration performance and pollutant removal efficiency were investigated. A series of measurements, i.e., three dimensional excitation-emission matrix (EEM) analysis, gel filtration chromatography (GFC), Fourier transform infrared (FTIR) analysis, characterization of membrane foulant components, were systematically carried out. Test results showed that the AnMBR could achieve good chemical oxygen demand (COD) removal. Total nitrogen (TN) was also eliminated by 25-30% by the reactor. Under temperature above 20 ℃, the AnMBR could be successfully operated for 86 days without any cleaning at membrane flux 5-10 L/(m 2 h). It was also found that the membrane fouling was mainly caused by the sludge cake layer formed on membrane surfaces. The major components of foulants were sludge particles; however, the biopolymers, such as proteins, polysaccharides, humic substances, etc., especially organic matters with high molecular weight (MW), also played an important role in the membrane fouling.

Developments and future potentials of anaerobic membrane bioreactors (AnMBRs)

“…In submerged AnMBRs, the cake formation was identified as a dominant feature contributing to the deterioration of membrane performance (Lin et al 2010). Wang et al (2010) mentioned that membrane fouling was mainly caused by the sludge cake layer formed on membrane surfaces which includes sludge particles and biopolymers such as proteins, polysaccharides and humic substances. However the contribution from sludge particles was recognized as the major biofouling over the biopolymers (Wang et al 2010).…”

“…Wang et al (2010) mentioned that membrane fouling was mainly caused by the sludge cake layer formed on membrane surfaces which includes sludge particles and biopolymers such as proteins, polysaccharides and humic substances. However the contribution from sludge particles was recognized as the major biofouling over the biopolymers (Wang et al 2010). The studies of Lin et al (2011aLin et al ( , 2011b indicates the significance of smaller flocs having higher filtration resistance over the bulk sludge due to 1.5 times higher bound EPS and significant variations of microbial community structure in smaller flocs.…”

“…The successful operations of AnMBRs indicates the operational fluxes of 5-20 L/m 2 h for longer periods of time (Wang et al 2010, Lin et al 2011b. However compared to aerobic MBRs (Le-Clech et al 2006, Chang et al 2002 where the operating fluxes are much higher, the AnMBR needs improvements.…”