Bioelectrochemical Dechlorination of 1,2-DCA with an AQDS-Functionalized Cathode Serving as Electron Donor

In the present study we describe a simple method to immobilize the redox mediator anthraquinone-2,6-disulfonate (AQDS) at the surface of graphite electrodes, by means of a commercial anion exchange membrane. Cyclic voltammetry experiments confirmed the efficacy of the immobilization protocol and the long-term (over 70 days) electrochemical stability of the AQDS-functionalized electrode. Potentiostatic (-300 mV vs. SHE) batch experiments proved the capability of the electrode in accelerating the bioelectrochemical reductive dechlorination of the groundwater contaminant 1,2-dichloroethane (1,2-DCA) to harmless ethene by a mixed microbial culture, by serving as electron donor in the process. Considering the reported broad range of anodic and cathodic reactions catalyzed by AQDS, the herein described functionalized electrode has a remarkable potential for application in the environmental and industrial sector.