title: Impact of a metabolic uncoupler, 2,4-dichlorophenol on minimization of activated sludge production in membrane bioreactor.
abstract: This study investigated the effects of 2,4-dichlorophenol on reduction of activated sludge in membrane bioreactors. Significant inhibition on sludge growth and slight reduction in COD removal were observed at higher 2,4-dichlorophenol dosages. The deviation between relative specific COD removal rate (q/q0) and relative specific growth rate (μ/μ0) suggested that a minimum 2,4-dichlorophenol concentration was required for uncoupling of anabolism and catabolism. With the increase of the dosage of 2,4-dichlorophenol, stepwise improvement of biomass bioactivity and the reduction in activated sludge production were achieved simultaneously. Compared with the control bioreactor, the peak distribution of floc size in the 2,4-dichlorophenol added bioreactor shifted to a range of smaller floc size. Besides, addition of 2,4-dichlorophenol caused little variation of microorganism community structure and SVI value of the sludge. After 24-hour operation, the residue 2,4-dichlorophenol concentration in the bioreactors was reduced to a negligible level.
authors.affiliation: College of Architecture and Environment, Sichuan University, Chengdu 610065, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Song
authors.forename: Jiang
authors.initials: J
authors.lastname: Wenju
authors.forename: Tang
authors.initials: T
authors.lastname: Qiong
authors.forename: Li
authors.initials: L
authors.lastname: Yaozhong
mesh_terms: D001420:Bacteria, Aerobic / Q000254:growth & development* / Q000378:metabolism; D019149:Bioreactors / Q000382:microbiology*; D002733:Chlorophenols / Q000032:analysis / Q000737:chemistry*; D004579:Electron Transport; D004734:Energy Metabolism; D008567:Membranes, Artificial; D008855:Microscopy, Electron, Scanning; D012722:Sewage / Q000032:analysis* / Q000382:microbiology*; D013997:Time Factors; D014475:Uncoupling Agents / Q000032:analysis / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*
chemical_list: D002733:Chlorophenols; D008567:Membranes, Artificial; D012722:Sewage; D014475:Uncoupling Agents; C004762:2,4-dichlorophenol