Devising cost-effective
electrochemical catalyst system for the
efficient degradation of chlorinated aromatic compounds is urgently
needed for environmental pollution control. Herein, a Fe-ZSM-5 zeolite
was used as a suspended catalyst to facilitate the degradation of
lindane as a model chlorinated pesticide in an electrochemical system
consisting of the commercial DSA (Ti/RuO
2
-IrO
2
) anode and graphite cathode. It was found that the Fe-ZSM-5 zeolite
greatly accelerated the degradation of lindane, with the degradation
rate constant more than 8 times higher than that without Fe-ZSM-5.
In addition, the Fe-ZSM-5 zeolite widened the working pH range from
3 to 11, while efficient degradation of lindane in the absence
of Fe-ZSM-5 was only obtained at pH ≤ 5. The degradation of
lindane was primarily due to reductive dechlorination mediated by
atomic H* followed by
•
OH oxidation. Fe-ZSM-5 zeolite
could enrich lindane, H*, and
•
OH on its surface,
thus provided a suitable local environment for lindane degradation.
The Fe-ZSM-5 zeolite exhibited high stability and reusability, and
reduced the energy consumption. This research provides a potential
reduction–oxidation strategy for removing organochlorine compounds
through a cost-efficient Fe-ZSM-5 catalytic electrochemical system.