title: Correlation between fouling propensity of soluble extracellular polymeric substances and sludge metabolic activity altered by different starvation conditions.
abstract: Soluble extracellular polymeric substances (EPSs) cause membrane fouling in membrane bioreactors (MBRs), correlated with MBR sludge characteristics. Effects of F/M ratios on the evolution of soluble EPSs, fouling propensity of supernatants, and sludge metabolic activity were measured in this study in a two-period sequencing batch reactor (SBR). The experimental results show that fouling propensity was directly correlated with soluble-EPS concentration and composition. Sludge that had entirely lost active cells by long-term starvation released 64.4 ± 0.9 mg/L of humic acids, which caused a rapid increase in membrane resistance (40.67 ± 2.24 × 10(11) m(-1)) during fouling tests. During short-term starvation, induced by incubation at a normal to low F/M ratio of 0.05 d(-1), sludge can use previously secreted utilization-associated products (UAPs) to maintain endogenous respiration. Therefore, the strategies of accumulating sludge and prolonging sludge retention time in MBRs may create long-term starvation and promote membrane fouling.
authors.affiliation: Department of Environmental Engineering, National Chung Hsing University, 250 Kuo Kuang Rd., Taichung 402, Taiwan, ROC. siangchen.wu@gmail.com
authors.forename: Siang Chen
authors.initials: SC
authors.lastname: Wu
authors.forename: Chi Mei
authors.initials: CM
authors.lastname: Lee
mesh_terms: D057219:Biofouling; D001704:Biopolymers / Q000737:chemistry*; D019149:Bioreactors / Q000382:microbiology; D005110:Extracellular Space / Q000737:chemistry*; D012722:Sewage / Q000737:chemistry*; D012995:Solubility; D013347:Subcellular Fractions / Q000378:metabolism
chemical_list: D001704:Biopolymers; D012722:Sewage