Application of bioelectrochemical systems for the treatment of wastewaters with sulfur species

Bioelectrochemical systems (BES) are an emerging technology that combines biological and electrochemical processes. Transfer of electrons driven by anode-respiring bacteria has been widely used in microbial fuel cell and microbial electrolysis cell. Recently, a growing interest exists in the use of BES for the treatment and potential elemental sulfur recovery of sulfur-laden wastewaters containing sulfate, sulfide, or other S species. This chapter reviews their application for anodic sulfide and elemental sulfur oxidation, cathodic sulfate reduction, and treatment of other S-containing compounds. The performance achieved with these processes and their interaction with organic matter, heavy metals, or elemental sulfur production is also examined. Clear drivers for the research in this field are the development of processes and its optimization to improve reaction rates, lowering energy requirements, design of new materials with higher catalytic activity, recovery of products as elemental sulfur, and improvement of operational and investment costs.