title: The effect of solids retention times on the characterization of extracellular polymeric substances and soluble microbial products in a submerged membrane bioreactor.
abstract: In this study, the effect of solids retention times (SRTs) on extracellular polymeric substances (EPS) and soluble microbial products (SMPs) were investigated in a membrane bioreactor (MBR) at SRTs of 10, 5 and 3 days. The results showed that more carbohydrates and proteins were accumulated at short SRT, which can due to the higher biomass activity in the reactor. The molecular weight (MW) distribution analysis suggested that macromolecules (MW>30 kDa) and small molecules (MW<1 kDa) were the dominant fraction of EPS and SMP, respectively. The reactor at shorter SRT had more small molecules and less macromolecules of carbohydrates. The MW distribution of total organic carbon (TOC) suggested that other organic moieties were exuded by microbes into the solution. The shorter SRT had more undefined microbial by-product-like substances and different O − H bonds in hydroxyl functional groups.
authors.affiliation: State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, PR China; Department of Civil and Environmental Engineering, University of California, Berkeley, CA 94720-1710, USA.
authors.forename: Liang
authors.initials: L
authors.lastname: Duan
authors.affiliation: State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, PR China. Electronic address: songyh@craes.org.cn.
authors.forename: Yonghui
authors.initials: Y
authors.lastname: Song
authors.affiliation: State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, PR China.
authors.forename: Huibin
authors.initials: H
authors.lastname: Yu
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, 1239 Siping Rd., Shanghai 200092, PR China.
authors.forename: Siqing
authors.initials: S
authors.lastname: Xia
authors.affiliation: Department of Civil and Environmental Engineering, University of California, Berkeley, CA 94720-1710, USA; National High-End Foreign Experts of China Program, Tongji University, 1239 Siping Rd., Shanghai 200092, PR China.
authors.forename: Slawomir W
authors.initials: SW
authors.lastname: Hermanowicz
mesh_terms: D019149:Bioreactors; D008567:Membranes, Artificial; D008970:Molecular Weight; D011108:Polymers / Q000737:chemistry*
chemical_list: D008567:Membranes, Artificial; D011108:Polymers
keywords: Extracellular polymeric substances; Membrane bioreactor; Molecular weight distribution; Solids retention times; Soluble microbial products