An effective electrochemical destruction of non-ionic surfactants on bismuth-modified lead dioxide anodes for wastewater pretreatment

Non-ionic surfactants are permanent components of wastewater of various origins, and their removal is necessary for sewage treatment. A new method of electrochemical treatment of wastewater for non-ionic surfactant destruction has been proposed. Effective destruction of both alkoxylated and phenoxylated non-ionic surfactants was performed using β-Pb 1– x Bi x O 2–0.5 x anodes prepared by electrodeposition. The method proposed is based on the generation of active oxygen-containing species (e.g., OH • , HO 2 • ) at the anode followed by chemical interaction between these radicals and organic molecules, which results in the destruction of pollutants. Oxide materials obtained by electrodeposition contained ~ 4.5 % of bismuth and have the β–PbO 2 lattice. The insertion of bismuth into the composition of lead dioxide prepared by electrodeposition resulted in an increase in their specific surface area from 0.66 to 2.5 m 2 g −1 . Modification of β–PbO 2 by bismuth led to the shift of oxygen evolution potentials toward more positive values. Effective electrooxidation of non-ionic surfactants was achieved in the solutions exposed to electrochemical treatment. There were no accumulations of metabolites in the solutions during electrolysis. Chemical oxygen demand decreased from 80 to 5 mg O 2 dm −3 , and total organic carbon (TOC) decreased from 24 to 1.5 ppm during 1 h of the electrochemical treatment. The electrode material was stable under electrolysis conditions. No accumulation of both lead and bismuth species in the solution under electrochemical treatment was found.