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-Pb1–xBixO2–0.5x anodes prepared by electrodeposition. The method proposed is based on the generation of active oxygen-containing species (e.g., OH•, HO2•) 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–PbO2 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 m2 g−1. Modification of β–PbO2 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 O2 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.