Ahmed, Zubair Cho, Jinwoo Lim, Byung-Ran Song, Kyung-Guen Ahn, Kyu-Hong 2024-01-21T01:34:46Z 2024-01-21T01:34:46Z 2021-08-31 2007-01-15 0376-7388 https://pubs.kist.re.kr/handle/201004/134740 In this study, the effect of sludge retention time (SRT) on membrane bio-fouling was investigated in a membrane bioreactor (MBR) equipped with a sequential anoxic/anaerobic reactor. Specific cake resistance (alpha), trans-membrane pressure (TMP), mixed liquor suspended solids (MLSS), particle sizes, extracellular polymer substances bound in sludge (bound-EPS) and their correlations with membrane bio-fouling were studied at different SRTs. As SRT decreased to 20 days, the bound-EPS per unit of biomass increased, and consequently, the value of a increased, which resulted in the rise of TMP. However, the reduction of the bound-EPS content was relatively small as compared to a significant decrease in the value of alpha at longer SRTs (above 60 days). These observations suggest that colloidal particles significantly contribute to membrane bio-fouling. In addition, the diversity of the microbial community structure of activated sludge in the MBRs was observed using the respiratory quinone profile. The ubiquinone species containing UQ-8, belonging to the class beta-Proteobacteria type were the major constituents of the microbial community structure. The mole fraction of menaquinone MK-6, -7 and -8(H2) increased as SRT increased. Thus, the results of this study indicate that growth of microorganisms belonging to the delta- and epsilon-subclass of Proteobacteria as well as the members of the Cytophaga-Flavobacterium cluster increased at longer SRTs. (c) 2006 Elsevier B.V. All rights reserved. English ELSEVIER SCIENCE BV WASTE-WATER TREATMENT QUINONE PROFILE METHOD ACTIVATED-SLUDGE RESPIRATORY QUINONES SP-NOV. PERFORMANCE FILTRATION OPERATION SEWAGE SYSTEM Effects of sludge retention time on membrane fouling and microbial community structure in a membrane bioreactor Article 10.1016/j.memsci.2006.10.036 1 JOURNAL OF MEMBRANE SCIENCE, v.287, no.2, pp.211 - 218 JOURNAL OF MEMBRANE SCIENCE 287 2 211 218 scie scopus 000243815100007 2-s2.0-33845435205 Engineering, Chemical Polymer Science Engineering Polymer Science Article WASTE-WATER TREATMENT QUINONE PROFILE METHOD ACTIVATED-SLUDGE RESPIRATORY QUINONES SP-NOV. PERFORMANCE FILTRATION OPERATION SEWAGE SYSTEM membrane bioreactors (MBR) membrane bio-fouling sludge retention time (SRT) microbial community structure quinone profile