Thin film microfluidic reactors in electrochemical advanced oxidation processes for wastewater treatment: A review on influencing parameters, scaling issues, and engineering considerations

The use of microfluidic electrochemical reactors has been introduced several decades ago, but their application in the field of wastewater treatment is more recent (2010). The parallel development of electrochemical advanced oxidation processes (EAOPs) as promising technologies for effluent treatment make them good candidates to be implemented as thin film cells. This allows favoring the mass transfer, which is particularly interesting for heterogenous electro-oxidation. Moreover, the energy requirement is reduced, while there is possibility to treat low-conductivity solutions. This review intends to provide instructions on the main operating parameters to be optimized during the EAOPs treatment. Directions on engineering aspects have been given to overcome the main drawbacks of microreactors, such as fouling, scaling, and low treatment capacity, based on recent encouraging results given in literature. The promising development of hybrid processes that combine electroseparation with electroconversion would also benefit from such reactor designs. Flow chart presenting the influencing parameters with the associated advantages (blue) and drawbacks (red) in microfluidic electrochemical reactor for the treatment of water and wastewater.image