Sulfate contamination can cause substantial environmental and health problems including a potential contribution to methylation of mercury, sulfide toxicity and eutrophication. High-strength sulfate wastewaters are generated by various industrial activities such as pulp and paper milling and mining operations. Bioelectrochemical systems have promising potential to clean up a variety of contaminants including high levels of sulfate. We have developed a novel bioreactor to stimulate and sustain biological sulfate reduction and simultaneously facilitate the subsequent removal of the reduced sulfide by applying iron electrolysis under low electrical potential. In this work, flow-through sediment bioelectrochemical reactors with stainless steel electrodes were used to test this system. The efficacy of sulfate reduction and sulfide precipitation was tested in systems inoculated with either a sediment microbial consortium or a pure culture of a strain of <i>Desulfovibrio.</i> A synthetic mine water media with 1000 mg/L sulfate was treated with 0-2V electric potential producing cathodic hydrogen and anodic iron dissolution. Open circuit reactors were used as a control. The matrix materials in the reactors were examined with scanning electron microscopy and x-ray diffraction to identify solid phase mineral formation. A mathematical model was developed and validated with the system, which will be used for process optimization. This study will result in a proof of concept application of electrical potential to provide electron donor substrates to biological sulfate treatment with simultaneous sulfide removal in a controlled manner.

Enhanced biological sulfate reduction coupled to iron electrolysis in a flow-through bioelectrochemical reactor

255th National Meeting (2018)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.