Degradation of of ortho-chlorophenol, para-chlorophenol, and 2,4-dichlorophenoxyacetic acid by the bacterial community of anaerobic sludge

The bacterial community of anaerobic sludge could degrade o-chlorophenol, p -chlorophenol, and 2,4-dichlorophenoxyacetic acid at concentrations as high as 100 mg/l. The time needed for the degradation of a given chlorinated ph enol derivative increased 1.5- to 2-fold upon a twofold increase in its con centration (from 50 to 100 mg/l). The duration of the adaptation period dep ended on the compound studied and on its concentration. The degradation of 2,4-dichlorophenoxyacetic acid proceeded via 2,4-dichlorophenol and p-chlor ophenol as intermediates; the degradation of o-chlorophenol occurred with t he formation of phenol. The dynamics of p-chlorophenol degradation and chlo ride ion accumulation were studied.