Sewage Sludge-Derived catalyst for extremely efficient electrocatalytic elimination of organic pollutants in water

Abstract

Electrochemical advanced oxidation processes (EAOPs) are promising technologies for the elimination of organic pollutants in water, but the high cost of the catalysts and treatment process restrict their large-scale application. Herein, highly efficient carbon-based catalysts for EAOPs were obtained by directly pyrolyzing low-cost sewage sludge, over which the elimination rates were up to 98% for methyl orange (MO) and 88% for tetracycline (TC). A precise electrochemical testing system demonstrated that the S-9/Ti electrode with 1.2 g catalyst loading owns the specific energy consumption value for 98% MO (5 mg/L) degradation was only 0.0112 kWh/g, and the value for 88% TC (1*10-4 M) degradation was only 0.0039 kWh/g, in 8 h. Furthermore, active species capture experiments demonstrated that the •OH and •O2– radicals produced over the catalysts were the main oxidants for the elimination of pollutants. This study broadens the horizon for the resource utilization of sewage sludge and provides a strategy to realize the concept of “treating pollution with waste”.