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 (Fe(0)) resulted in sharp decrease of p,p'-DDT, whereas there was no extra effect when 2% (w/w) aluminum sulfate (Al(2)(SO(4))(3)) was added to the Fe(0) treatment. These results suggest that Fe(0) could effectively promote the reductive dechlorination of p,p'-DDT and its metabolites while Al(2)(SO(4))(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 Fe(0), the polluted soil produced much less CO(2) while the addition of Al(2)(SO(4))(3) counteracted its negative effect to much extent.