Treatment of Soil Washing Solutions by Electrochemical Advanced Oxidation

Soil washing (SW) is one of the excavation techniques widely used to transfer the organic and inorganic pollution from soil matrix to liquid media, as a soil remediation answer. The complex mixture of biorecalcitrant SW solutions makes it difficult to treat with conventional biological and physico-chemical processes. Electrochemical technologies have been proposed to treat this kind of effluent, especially electrochemical advanced oxidation processes (EAOPs) that implement strong oxidizing agents such as hydroxyl radicals (•OH), mainly responsible for the organic compound degradation. The mechanisms, the main impacting parameters, and the treatment efficiency of EAOPs implementing homogeneous or heterogeneous catalysis are described. The efficiency of paired catalysis process as well as transfer competitions and the reactor configurations are also presented as engineering factors to be optimized for upscaling phase.