title: 2,4,6-trichlorophenol (TCP) photobiodegradation and its effect on community structure.
abstract: The mechanisms occurring in a photolytic circulating-bed biofilm reactor (PCBBR) treating 2,4,6-trichlorophenol (TCP) were investigated using batch experiments following three protocols: photodegradation alone (P), biodegradation alone (B), and intimately coupled photodegradation and biodegradation (P&B). Initially, the ceramic particles used as biofilm carriers rapidly adsorbed TCP, particularly in the B experiments. During the first 10 min, the TCP removal rate for P&B was equal to the sum of the rates for P and B, and P&B continued to have the greatest TCP removal, with the TCP concentration approaching zero only in the P&B experiments. When phenol, an easily biodegradable compound, was added along with TCP in order to promote TCP mineralization by means of secondary utilization, P&B was superior to P and B in terms of mineralization of TCP, giving 95% removal of chemical oxygen demand (COD). The microbial communities, examined by clone libraries, changed dramatically during the P&B experiments. Whereas Burkholderia xenovorans, a known degrader of chlorinated aromatics, was the dominant strain in the TCP-acclimated inoculum, it was replaced in the P&B biofilm by strains noted for biofilm formation and biodegrading non-chlorinated aromatics.
authors.affiliation: Department of Environmental Engineering, College of Life and Environmental Science, Shanghai Normal University, 200234, Shanghai, People's Republic of China. zhym@shnu.edu.cn
authors.forename: Yongming
authors.initials: Y
authors.lastname: Zhang
authors.forename: Xuejing
authors.initials: X
authors.lastname: Pu
authors.forename: Miaomiao
authors.initials: M
authors.lastname: Fang
authors.forename: Jun
authors.initials: J
authors.lastname: Zhu
authors.forename: Lujun
authors.initials: L
authors.lastname: Chen
authors.forename: Bruce E
authors.initials: BE
authors.lastname: Rittmann
mesh_terms: D001419:Bacteria / Q000737:chemistry / Q000145:classification / Q000302:isolation & purification / Q000528:radiation effects; D018407:Bacterial Physiological Phenomena; D001673:Biodegradation, Environmental / Q000528:radiation effects; D018441:Biofilms; D019149:Bioreactors / Q000382:microbiology*; D002733:Chlorophenols / Q000737:chemistry / Q000378:metabolism*; D007700:Kinetics; D008969:Molecular Sequence Data; D010782:Photolysis; D012722:Sewage / Q000737:chemistry / Q000382:microbiology; D014466:Ultraviolet Rays
chemical_list: D002733:Chlorophenols; D012722:Sewage; C024564:2,4,6-trichlorophenol