Removal of sulfamethazine antibiotics using Ce-Fe-graphene nanocomposite as catalyst by Fenton-like process

摘要

The presence of sulfonamide (SMT) antibiotics in aquatic environments has received increasing attention in recent years, and they are ubiquitous pollutants which cannot be effectively removed by conventional wastewater treatment processes. In this paper, the nanocomposites Ce~0/Fe~0-reduced graphene oxide (Ce~0/Fe~0-RGO) were synthesized through chemical reduction method, and characterized by Raman and FTIR before and after use. The addition of RGO can prevent the agglomeration of Ce~0 and Fe~0. The elimination of SMT can be divided into adsorption and degradation process. The adsorption of SMT onto the catalyst can enhance its degradation. The effect of pH value, concentration of H_2O_2, catalyst dosage, temperature and initial SMT concentration on the removal efficiency of SMT was determined. When pH = 7, T = 25 ℃, H_2O_2 = 8 mM, Ce~0/Fe~0-RGO = 0.5 g/L, SMT = 20 mg/L, the removal efficiency of SMT and TOC was 99% and 73%, respectively. The stability of the catalysts was evaluated with repeated batch experiments using ethanol, water and acid as solvents to wash the used catalysts, respectively. The surface change of the catalysts after each use was characterized by Raman and FTIR analysis. The intermediates were detected by GC-MS and IC, the possible degradation pathway of SMT was tentatively proposed.