Degradation of N,N-diethyl-m-toluamid (DEET) on lead dioxide electrodes in different environmental aqueous matrixes.

This study investigates the electrochemical degradation of N,N-diethyl-m-toluamide (DEET) on PbO2 and Bi-PbO2 anodes. The difference in electrode crystalline structure was responsible for the better DEET degradation and TOC removal on PbO2 than on Bi-PbO2. In 1 M Na2SO4, the degradation efficiency and apparent rate constant (kapp) of DEET oxidation on PbO2 increased with the increase in current density or temperature (activation energy=24.4 kJ mol(-1)). The kapp values in DEET-spiked environmental matrixes (municipal wastewater treatment plant secondary effluent (MWTPSE), groundwater (GW), and river water (RW)) were the same (6.05×10(-4) s(-1)), but significantly smaller than that in 1 M Na2SO4 (2.23×10(-3) s(-1)). The TOC removal efficiency was better in MWTPSE than in RW and GW; however, the mineralization current efficiencies in MWTPSE and RW were similar but higher than that in GW. During electrolysis, the aromaticity was lower in GW than in RW.