Enhanced Biotransformation of Dinitrotoluene by Mediator-Functionalized Polypyrrole Composites

Abstract

The continuous dosing and discharge of water soluble redox mediators such as biologically recalcitrant compounds will result in the secondary contamination. The immobilized redox mediator prepared by incorporation of anthraquinonedisulphon-ate (AQDS) during the electropolymerization of pyrrole monomer on active carbon felt (ACF), AQDS/PPy/ACF, was used for catalyzing bioreduction of 2,4-dinitrotoluene(2,4-DNT) in this study. The results showed that the morphology of the PPy films deposits on ACF are characterized by some globular structure; AQDS/PPy/ACF exhibited good catalytic activity and stability for 2,4-DNT, the enhanced reduction rates obtained in the incubations with AQDS/PPy/ACF was about 5 times that without AQDS/PPy/ACF, the corresponding first-order reduction rate constant k reached 0.045 h-1; 2,4-DNT was reduced to be 2,4-diaminotoluene via 2-amino-4-nitrotoluene and 4-amino-2-nitrotoluene in the system.