Chlorophenol removal from soil suspensions : effects of a specialised microbial inoculum and a degradable analogue

Two soils of different contamination history were tested in slurry for their self-remediability towards mono-, diand trisubstituted chlorophenols. The landfill soil showed poor ability in removing the compounds. Instead, the soil from the golf course, treated for many years with a 2,4,6-trichlorophenol derivative (Prochloraz), remediated different concentrations of the same 2,4,6TCP, 2,4-dichlorophenol and monochlorophenol isomers, singly and in mixtures, at varying degradation rates. Ralstonia eutropha TCP, a specialised microorganism capable of degrading 2,4,6TCP, proved highly efficient in removing the compound from both tested soils. The same microbial inoculum allowed total removal of the ternary mixture of monochlorophenol isomers from the golf course soil, but it did not accelerate the removal of the same compounds when singly supplied. The addition of phenol as a degradable analogue was more effective in co-metabolically removing not only the single monochlorophenols,but also their mixtures, the removal occurring faster and independently of the presence of the microbial inoculum. From the golf course soil, a microorganism, phenotypically and genetically identical to R. eutropha TCP, was isolated and classified as R. eutropha TCP II.