An innovative strategy integrating the use of biosurfactant (BS) and persulphate activated by chelated
iron for the decontamination of soil from an emerging
pollutant chlorophene was studied in laboratory down-flow columns along with other persulphate activation
aids including combined application of persulphate and
hydrogen peroxide, and persulphate activation with
sodium hydroxide. Although BS addition improved
chlorophene removal by the persulphate treatment, the addition of chelated
iron did not have a significant influence. Combined application of persulphate with
hydrogen peroxide resulted in a significant (p≤.05) overall improvement of
chlorophene removal compared with treatment with persulphate only. The highest removal rate (71%) of
chlorophene was achieved with the base-activated persulphate, but only in the upper part (of 0.0-3.5 cm in depth) of the column. The chemicals at the applied dosages did not substantially influence the Daphnia magna toxicity of the effluent.
Dehydrogenase activity (DHA) measurements indicated no substantial changes in the microbial activity during the persulphate treatment. The highest oxygen consumption and a slight increase in DHA were observed with the BS addition. The combined application of persulphate and BS at natural soil pH is a promising method for
chlorophene-contaminated soil remediation.
Hydroquinone was identified among the by-products of
chlorophene degradation.