Norfloxacin degradation in synthetic human urine using nickel converter slag-laterite heterogeneous Electro-Fenton process

Abstract

Human urine is a point source of environmental antibiotic-related microcontaminants. Thus, developing dedicated treatment technologies for the effective degradation of urine antibiotics is highly desirable in large-scale human urine reuse. This work studied the antibiotic removal in synthetic human urine by the nickel converter slag-laterite (NCS-LA) heterogeneous Electro-Fenton (heterogeneous-EF) process. The objective was to assess the feasibility of this advanced oxidation process (AOP) for antibiotic elimination in synthetic human urine. Results indicated that the artificial aeration mode of 0.5 L/min could reach 95.25 % norfloxacin (NOR) degradation efficiency in synthetic human urine under established conditions (catalyst dosage 60 g/L, initial pH 3, applied current 80 mA). The natural aeration mode (the NOR degradation efficiency was only 9.49 %) was unsuitable for a single chamber undivided reactor with graphite felt (GF) cathode and Ti/RuO2-IrO2 anode. In cycling experiments conducted in synthetic urine, NCS-LA showed excellent reusability and stability. The NOR degradation efficiency decreased by only 5.01 % after six cycles. The leaching concentrations of heavy metals (Fe, Ni, Co and Cu) after each cycle were low (0.01–3.72 mg/L). This strategy is expected to clear the way for the recovery and reuse of urine.