Evaluation of accelerated dechlorination of p,p′-DDT in acidic paddy soil

The reductive dechlorination and behavior of p,p′-dichlorodiphenyltrichloroethane (p,p′-DDT) was investigated in a paddy soil. Treatment with 5% (w/w) metallic iron (Fe0) resulted in sharp decrease of p,p′-DDT, whereas there was no extra effect when 2% (w/w) aluminum sulfate (Al2(SO4)3) was added to the Fe0 treatment. These results suggest that Fe0 could effectively promote the reductive dechlorination of p,p′-DDT and its metabolites while Al2(SO4)3 did not show any effect on those processes. Furthermore, p,p′-DDT and its daughter compounds inhibited holistic soil respiration greatly at first but could be metabolized by certain species of indigenous microorganisms after a period of adaptation time in the soil. When treated with Fe0, the polluted soil produced much less CO2 while the addition of Al2(SO4)3 counteracted its negative effect to much extent.