title: Influence of solids retention time on membrane fouling: characterization of extracellular polymeric substances and soluble microbial products.
abstract: The objective of this study was to investigate the influence of solids retention time (SRT) on membrane fouling and the characteristics of biomacromolecules. Four identical laboratory-scale membrane bioreactors (MBRs) were operated with SRTs for 10, 20, 40 and 80 days. The results indicated that membrane fouling occurred faster and more readily under short SRTs. Fouling resistance was the primary source of filtration resistance. The modified fouling index (MFI) results suggested that the more ready fouling at short SRTs could be attributed to higher concentrations of soluble microbial products (SMP). Fourier transform infrared (FTIR) spectra indicated that the SRT had a weak influence on the functional groups of the total extracellular polymeric substances (TEPS) and SMP. However, the MBR under a short SRT had more low-molecular-weight (MW) compounds (<1 kDa) and fewer high-MW compounds (>100 kDa). Aromatic protein and tryptophan protein-like substances were the dominant groups in the TEPS and SMP, respectively.
authors.affiliation: a State Key Laboratory of Environmental Criteria and Risk Assessment , Chinese Research Academy of Environmental Sciences , Beijing , P.R China.
authors.forename: Liang
authors.initials: L
authors.lastname: Duan
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Tian
authors.forename: Yonghui
authors.initials: Y
authors.lastname: Song
authors.forename: Wei
authors.initials: W
authors.lastname: Jiang
authors.forename: Yuan
authors.initials: Y
authors.lastname: Tian
authors.forename: Shan
authors.initials: S
authors.lastname: Li
mesh_terms: D057219:Biofouling; D019149:Bioreactors; D005374:Filtration; D008567:Membranes, Artificial; D011108:Polymers / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods
chemical_list: D008567:Membranes, Artificial; D011108:Polymers
keywords: extracellular polymeric substances; membrane bioreactor; membrane fouling; solids retention time; soluble microbial products