Roles of H2 evolution overpotential, materials porosity and cathode potential on mineral electro-precipitation in microfluidic reactor – New criterion to predict and assess interdependency

The influence of cathode materials including carbonaceous electrode on the cathodic mineral scaling behavior in a context wastewater treatment is investigated for first time and particularly thin film microfluidic reactors. kinetics CaCO3 Mg(OH)2 electro-precipitations were evaluated with different (with distinct porosities, electroactive surface area (Selec) hydrogen (H2) evolution overpotential (HEP)) by varying applied current densities interelectrode distances (delec). Three tested, carbon paper (porosity = 89%; Selec 175 cm2), graphite 15%; 85 stainless steel 0%; 80 cm2). An optimal condition to minimize deposition could be found configuration (100 µm delec) using material being able increase potential (EC) so decrease OH− production. At higher delec, led less electro-precipitation compared graphite. These results newly highlight that rate strongly depends EC values, which vary density as well properties (porosity, Selec, HEP). A new criterion, namely EC/HEP, has been introduced assess interdependency those parameters. Interestingly, maximal was noticed at EC/HEP ≈ 1.3 porous non-porous materials. This further announces possibility predict range required according objective, crucial real applications electrolysis treatment.