Role of anodically electrogenerated hydroxyl radicals in minimizing mineral cathodic electroprecipitation in the presence of hard water
Document Type
Article
Publication Date
5-1-2023
Abstract
Electrochemical systems are attracting increasing interest in environmental protection as relatively sustainable processes, particularly in wastewater treatment and reuse. However, cathode scaling in electrochemical pro-cesses for wastewater treatment is a major issue that is often overlooked. It is proposed for the first time to investigate the anodic contribution towards CaCO3 electroprecipitation phenomena under the advanced elec-trooxidation conditions applied to remove organic biorecalcitrant pollutants. The contribution of the reaction of the hydroxyl radical ((OH)-O-center dot) with carbonates, which reduces cathodic scaling at a micrometric interelectrode distance (500 mu m) and at a high current density (16 mA cm(-2)), is described in detail. In addition, the anti-scaling effect of local anodic acidification should be considered. A new kinetic model of electroprecipitation fits the experimental curves well (root mean square error (RMSE) < 0.19 for Ca2+) and confirms this anodic role, combined with the gas hindrance and scale detachment induced by gas bubble electrogeneration at sufficiently high current intensities.
Keywords
Calcium carbonate, Electrooxidation, Electroprecipitation, Microfluidic reactor, Modelling, Wastewater treatment
Divisions
sch_che
Funders
French Ministry of Higher Education, Research and Innovation (MESRI),Carnot ICEEL,LTSER Zone Atelier du Bassin de la Moselle (ZAM),European regional development fund program (CPER SusChemProc)
Publication Title
Electrochemistry Communications
Volume
150
Publisher
Elsevier
Publisher Location
STE 800, 230 PARK AVE, NEW YORK, NY 10169 USA