3D Fe/Cu-PEROVskites for electrochemically assisted TREATment of wastewaters – PEROV-TREAT

PEROV-TREAT aims at integrating perovskite-based porous materials in an electrochemical process for wastewater treatment in order to improve the treatment of persistent micropollutants and the management of antibiotic resistance, with the objective of reusing treated wastewaters. The application will focus on the tertiary treatment of wastewaters, an effluent from the pharmaceutical industry and a hospital effluent. The effectiveness of the process will be assessed using relevant indicators for micropollutants (ng/L ou µg/L) and occurrence of antibiotic resistant bacteria and genes. The Swiss micropollutant plan will be used for the selection of targeted micropollutants (carbamazepine, benzotriazole, irbesartan, hydrochlorothiazide). The main objective of this project is to obtain an optimal trade-off between (i) the reactivity for removing target compounds (degradation, mineralization), (ii) the minimization of by-product formation related to the organic/inorganic matrix (ClO3-, ClO4-, BrO3-, AOX), (iii) the stability of the electrocatalytic material for long-term applications. In this context, the use of perovskite-based materials appears currently as promising. They are used in various other processes for their stability features, while their catalytic properties allow for the activation of oxidants (H2O2, persulfates) for degradation of a large range of micropollutants, also through non-radical mechanisms.

Therefore, the project combines the expertise of 4 laboratories: LGE (U. Eiffel), specialized in electrochemical processes for water treatment, which coordinates the project; UCCS (U. Lille), specialized in the synthesis and shaping of heterogeneous catalysts; IC2MP (U. Poitiers), specialized in the study of catalyst reactivity and reaction mechanisms; IEM (U. Montpellier) specialized in the conception and monitoring of innovative processes for water treatment at pilot scale.

The novelty of the project is based on the integration of perovskite-based porous materials in an electrochemical process, and the improvement of the understanding of relations between material structure and (electro)catalytic properties for water treatment. Different perovskites will be synthesized for tuning their reducibility of transition metals composition (Fe/Cu) and the concentration of ionic vacancies. Shaping as porous materials using polystyrene templating or impregnation of commercial porous electrodes (UCCS) will be performed, with targeted pore size between 10 and 100 µm for improving mass transport conditions while limiting issues related to pressure drop and fouling. A multi-scale methodology will thereafter be implemented for studying the relations between material structures and (electro)catalytic properties, using measurements of reducibility and mobility of oxygen by isotopic exchange (IC2MP). LGE will assess the influence of the nature of catalysts and process configuration on (i) the formation of reactive species and reaction mechanisms, (ii) the formation of undesired by-products, (iii) the stability of (electro)catalysts. The most promising materials will be then integrated at IEM in an electrocatalytic microfiltratation process at laboratory pilot-scale (5 L/h). The pilot-scale design will be based on modeling results of reactive transport in order to optimize mass transport conditions for the treatment of low concentrations of micropollutants. The pilot-scale experiments will allow for the evaluation of process performances for the treatment of real effluents (municipal, hospital, pharmaceutical industry wastewater) using relevant indicators directly related to current priorities (micropollutants, PFAS, antibioresistance).