Advanced hybrid electro-separation/electro-conversion systems for wastewater treatment, reuse and recovery: Compromise between symmetric and asymmetric constraints

Abstract

Wastewater treatment with reuse and recovery of value-added compounds for valorization is of rising interest, and the combination of electro-separation and electro-conversion processes could be a promising solution to both environmental and resource availability problems. The more recent concomitant development of both electrochemical advanced oxidation processes and materials with new properties make the older electro-separation technologies regain visibility and interest. The electrofiltration/electrooxidation or electroreduction, electrosorption/electrooxidation, electrocoagulation/electro-Fenton, electroprecipitation/electrooxidation and electrodeposition/electrooxidation have been particularly critically reviewed. The conventional flow-by or flow-through parallel-plate and concentric cylinders design do not suffice to face the antagonist requirements in such simultaneous multiple electroproccesses. Innovative designs are needed and emerging concepts such as reactive electro-mixing are a possibility. Further modeling and scale-up studies based on revised theory are required in the future.