title: Effects of hydraulic retention time and bioflocculant addition on membrane fouling in a sponge-submerged membrane bioreactor.
abstract: The characteristics of activated sludge and membrane fouling were evaluated in a sponge-submerged membrane bioreactor (SSMBR) at different hydraulic retention times (HRTs) (6.67, 5.33 and 4.00h). At shorter HRT, more obvious membrane fouling was caused by exacerbated cake layer formation and aggravated pore blocking. Activated sludge possessed more extracellular polymeric substances (EPS) due to excessive growth of biomass and lower protein to polysaccharide ratio in soluble microbial products (SMP). The cake layer resistance was aggravated by increased sludge viscosity together with the accumulated EPS and biopolymer clusters (BPC) on membrane surface. However, SMP showed marginal effect on membrane fouling when SSMBRs were operated at all HRTs. The SSMBR with Gemfloc® addition at the optimum HRT of 6.67h demonstrated superior sludge characteristics such as larger floc size, less SMP in mixed liquor with higher protein/polysaccharide ratio, less SMP and BPC in cake layer, thereby further preventing membrane fouling.
authors: Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology, Sydney, Broadway, NSW 2007, Australia.
authors: Lijuan
authors: L
authors: Deng
authors: Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology, Sydney, Broadway, NSW 2007, Australia.
authors: Wenshan
authors: W
authors: Guo
authors: Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology, Sydney, Broadway, NSW 2007, Australia. Electronic address: h.ngo@uts.edu.au.
authors: Huu Hao
authors: HH
authors: Ngo
authors: School of Resources and Environmental Sciences, University of Jinan, Jinan 250022, PR China.
authors: Bing
authors: B
authors: Du
authors: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
authors: Qin
authors: Q
authors: Wei
authors: Department of Civil and Environmental Engineering, Faculty of Engineering, National University of Singapore, 1 Engineering Drive 2, E1A-02-19, Singapore 117576, Singapore.
authors: Ngoc Han
authors: NH
authors: Tran
authors: Institute of Environmental Engineering and Management, National Taipei University of Technology, No. 1, Sec. 3, Chung-Hsiao E. Rd, Taipei 106, Taiwan, ROC.
authors: Nguyen Cong
authors: NC
authors: Nguyen
authors: Institute of Environmental Engineering and Management, National Taipei University of Technology, No. 1, Sec. 3, Chung-Hsiao E. Rd, Taipei 106, Taiwan, ROC.
authors: Shiao-Shing
authors: SS
authors: Chen
authors: State Key Laboratory of Separation Membranes and Membrane Processes, School of Materials Science and Engineering, Tianjin Polytechnic University, Tianjin 300387, PR China.
authors: Jianxin
authors: J
authors: Li
mesh_terms: D000818:Animals; D057219:Biofouling; D018533:Biomass; D001704:Biopolymers / Q000032:analysis; D019149:Bioreactors; D005427:Flocculation; D008567:Membranes, Artificial; D011134:Polysaccharides / Q000032:analysis; D011161:Porifera; D011312:Pressure; D012722:Sewage / Q000737:chemistry; D012995:Solubility; D013997:Time Factors; D014783:Viscosity; D014835:Volatilization
chemical_list: D001704:Biopolymers; D008567:Membranes, Artificial; D011134:Polysaccharides; D012722:Sewage
keywords: Bioflocculant; Hydraulic retention time; Membrane bioreactor; Membrane fouling; Sponge