Electrochemical technologies coupled with biological treatments

When possible, the bioprocesses should be implemented to treat wastewater for their cost-effectiveness. However, many effluents are composed of biorecalcitrant organic pollutants, especially in industrial wastewaters. Advanced physico-chemical treatments are therefore needed to deal with these pollution levels. Electrochemical processes could be cost-effective solutions. However, the energy required to reach complete mineralization is often high. One promising combination would be to combine electrochemical processes that can remove xenobiotic compounds from effluent with biotechnologies that are able to mineralize the biodegradable fraction. Therefore, this review presents the most recent articles dealing with this combination, by mainly focusing on electrochemical advanced oxidation processes that demonstrated to have high removal efficiency for organic biorecalcitrant compounds. Additional and imperative information about the treatment strategy and the engineering aspects for the upscaling approach are also given. •A combination strategy between electrochemical and bio-processes is proposed.•Combinations between anodic oxidation and bioprocesses are reviewed.•Combinations between Fenton-based treatment and bioprocesses are discussed.•Combinations between electro-coagulation and bioprocesses are considered.•The engineering approach, scale-up studies, and future challenges are exposed.