Effect of Fe2+, Mn2+ catalysts on the performance of electro-Fenton degradation of antibiotic ciprofloxacin, and expanding the utilizing of acid mine drainage

In this work, the removal of ciprofloxacin (CIP) was studied by electro-Fenton (EF) technique using different molar ratio of Mn 2+ /Fe 2+ based on a chemically modified graphite felt (MGF) cathode. The CIP removal efficiency reached 95.62% in 30 min and the removal efficiency of total organic carbon (TOC) reached 94.00% in 8 h under optimal conditions (50 mg/L initial CIP concentration, 400 mA applied current, 2:1 M ratio of Mn 2+ /Fe 2+ , and 3 initial pH value). A possible pathway of CIP degradation was supposed according to the analysis of the by-products detected during the EF process. An expanding experiment for CIP removal was also conducted by using acid mine drainage (AMD) rich in iron and manganese to replace the homogeneous solution in EF, and the CIP removal efficiency of 89.00% in 60 min under the optimal conditions may assign new perspectives for organic pollutants removals by utilizing AMD.