Chlorophenols degradation by pentachlorophenol degrading bacteria Sphingomonas chlorophenolica in batch reactor

Chlorophenols are common environmental contaminants which have been using as the major compositions of wide-spectrum biocides in industry and agriculture. Many chlorophenols tend to persist in the environment, and they may become public health hazards. Among chlorophenols, pentachlorophenol (PCP) is a priority pollutant that has been using widely as a general biocide in commercial wood treatment. PCP is toxic to all forms of life since it is an inhibitor of oxidative phosphorylation. This research had studied the ability of PCP degrading bacterium Sphingomonas chlorophenolica to degrade and dechlorinate other chlorophenols. In addition, the characteristics of Sphingomonas chlorophenolica had also been investigated. The results indicated that Sphingomonas chlorophenolica was able to completely degrade 2,3,6-trichlorophenol (2,3,6-TCP), 2,4,6-trichlorophenol (2,4,6-TCP), 2,3,4,6-tetrachlorophenol (2,3,4,6-TeCP) and PCP within 38.1, 15.1, 11.8 and 11.8 hours, and to release concentration 50.1, 60.9, 63.7 and 58.5 mg/l chloride at the same period of time. Furthermore, the results showed that four kinds of chlorophenols had been dechlorinated approximately 100 % by the cell suspensions. In the presence of supplementary carbon sources (concentration 300 mg/l glucose, pyruvate, sodium acetate and concentration 150 mg/l 2,4,6-TCP, PCP), PCP removal efficiency increased with the presence of glucose or pyruvate, but the removal efficiency of 75 mg/l 2,4-dichlorophenol did not raise with the supplement of carbon sources