2,4,6-trichlorophenol (TCP) photobiodegradation and its effect on community structure
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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.
KeywordsBiodegradation Biofilm Photolysis Community structure Trichlorophenol
The authors acknowledge the financial support by the National Natural Science Foundation of China (50978164 and 50678102), the Special Foundation of Chinese Colleges and Universities Doctoral Discipline (20070270003), the Shanghai Leading Academic Discipline Project (S30406), and the United States National Science Foundation (0651794).
- American Public Health Association (APHA) (2001) Standard methods for the examination of water and wastewater, 22nd edn. American water works association and water pollution control federation, WashingtonGoogle Scholar
- Boyd S A, Mikesell M D, Lee J (1989) Chlorophenols in soils. In: Reactions and movement of organic chemicals in soils. Soil Science Society of America and American Society of Agronomy, Madison, 209–228Google Scholar
- Chang BV, Chiang CW, Yuan SY (1999) Microbial dechlorination of 2,4,6-trichlorophenol in anaerobic sewage sludge. Environ Sci Health B34:491–507Google Scholar
- Denef VJ, Park J, Tsoi TV, Rouillard JM, Zhang H, Wibbenmeyer JA, Verstraete W, Gulari E, Hashsham SA, Tiedje JM (2004) Biphenyl and benzoate metabolism in a genomic context: Outlining genome-wide metabolic networks in Burkholderia xenovorans LB400. Appl Environ Microbiol 70(8):4961–4970PubMedCrossRefGoogle Scholar
- Gómez-De Jesús A, Romano-Baez FJ, Leyva-Amezcua L, Juárez-Ramírez C, Ruiz-Ordaz N, Galíndez-Mayer J (2009) Biodegradation of 2,4,6-trichlorophenol in a packed-bed biofilm reactor equipped with an internal net draft tube riser for aeration and liquid circulation. J Hazard Mater 161(2–3):1140–1149Google Scholar
- Kazuya W, Maki T, Shigeaki H (1999) An outbreak of nonflocculating catabolic populations caused the breakdown of a phenol-digesting activated-sludge process. Appl Environ Microbiol 65(7):2813–2819Google Scholar
- Ramamoorthy S (1997) Chlorinated organic compounds in the environment. CRC Press, Boca RatonGoogle Scholar
- Reddy MP, Srinivas B, Kumari VD, Subrahmanyam M, Sharma PN (2004) An integrated approach of solar photocatalytic and biological treatment of N-containing organic compounds in wastewater. Toxicol Environ Chem 86(1–4):125–138Google Scholar
- Saw JH, Mountain BW, Feng L, Omelchenko MV, Hou S, Saito JA, Stott MB, Li D, Zhao G, Wu J, Galperin MY, Koonin EV, Makarova KS, Wolf YI, Rigden DJ, Dunfield PF, Wang L, Alam M ((2008)) Encapsulated in silica: genome, proteome and physiology of the thermophilic bacterium Anoxybacillus flavithermus WK1. Genome Biol 9((11)):R161.1–R161.16Google Scholar
- USEPA (1991) Water quality criteria summary, ecological risk assessment branch (WH-585) and human risk assessment branch (WH-550D). Health and Ecological Criteria Division, USEPA, WashingtonGoogle Scholar
- Xia Q, Zhang XH (1990) Manual on water quality standards. Environmental Science Press, BeijingGoogle Scholar