title: [2, 4, 6-Trichlorophenol Mineralization Promoted by Anaerobic Reductive Dechlorination of Acclimated Sludge and Extracellular Respiration Dechlorination Pathway].
abstract: In anaerobic conditions, the acclimation of activated sludge was studied with sodium lactate as the electron donor and 2,4,6-trichlorophenol as the electron acceptor. Metabolic characteristics of dechlorination were the focus of this study. The result showed highly efficient dechlorination on 2, 4, 6-trichlorophenol that the conversion rate reached to 100% in 9 - 24 h when initial concentrations of sodium lactate and 2,4, 6-trichlorophenol were 20 mmol x L(-1) and 40 - 80 μmol x L(-1), respectively. The intermediate product 2,4-dichlorophenol was found in low concentration (< 4.22 μmol x L(-1)). And 4-chlorophenol and phenol were the main products. Ortho chlorophenol (2, 4, 6-trichlorophenol, 2, 4-dichlorophenol) can be converted rapidly by acclimated sludge, while the further conversion of 4-chlorophenol and phenol was limited. The residues of anaerobic metabolism were degraded by aerobic sludge, among which 4-chlorophenol (initial concentration of 33 mol x L(-1)) removal rate was up to 100% under aerobic conditions. The acclimated bacteria can rapidly transfer Fe(III) and humus (AQDS) into reductive Fe(II) and AQH2DS which indicated that the dissimilatory iron reducing bacteria was enriched in the acclimated sludge. The electron mediator [Fe(III) and AQDS] significantly accelerated the dechlorination rate. The acclimated sludge could perform extracellular respiration dechlorination with electron mediators.
authors: Jia-xiu
authors: JX
authors: Song
authors: Ling
authors: L
authors: Li
authors: Fan-fan
authors: FF
authors: Sheng
authors: Cui-xiang
authors: CX
authors: Guo
authors: Yong-ming
authors: YM
authors: Zhang
authors: Zu-yuan
authors: ZY
authors: Li
authors: Tian-li
authors: TL
authors: Wang
mesh_terms: D001673:Biodegradation, Environmental; D002733:Chlorophenols / Q000737:chemistry*; D005290:Ferric Compounds; D054879:Halogenation; D010636:Phenols; D012722:Sewage / Q000737:chemistry*
chemical_list: D002733:Chlorophenols; D005290:Ferric Compounds; D010636:Phenols; D012722:Sewage; C029107:4-chlorophenol; C030683:2-chlorophenol; C024564:2,4,6-trichlorophenol; C004762:2,4-dichlorophenol