Preparation of fluorinated activated carbon for electro-Fenton treatment of organic pollutants in coking wastewater: The influences of oxygen-containing groups

摘要

Electro-Fenton is considered as a promising technology for treating of wastewater from industrial, and its performance can be significantly influenced by the H2O2 production on cathode catalysts. However, the catalysts developed recently suffer disadvantages of either poor H2O2 production activity or high cost for preparing catalysts. A low-cost and high-efficient electrocatalyst with high yield of H2O2 production is desirable for the treatment of real wastewater. In this work, a cost-efficient catalyst was fabricated by fluorination of commercial activated carbon. The fluorinated activated carbon possessed enhanced H2O2 production rate of 37.9 mg L-1 min(-1) (-0.4 V vs. SCE). As a result, nearly 100% of phenol was degraded within 15 min with a kinetic constant of 0.32 min(-1) at pH 3 (-0.4 V vs. SCE). Moreover, the COD of real secondary effluent from coking was decreased from 320 to 92 mg L-1 within 2 h, which met the discharge standard of the coking chemical industry (GB 16171-2012; COD < 100 mg L-1). Based on the XPS results, the oxygen-containing groups of pristine activated carbon played a crucial role in determining the F content and species of fluorinated activated carbon, which significantly influenced the performance of H2O2 production and electro-Fenton activity.