Enhanced removal of emerging contaminants using persulfate activated by UV and pre-magnetized Fe0

Emerging contaminants (ECs) have been frequently detected in the aquatic environment and have adverse effect on the environment. In our present study, four ECs (800 μgL −1 oxytetracycline (OTC) and tetracycline (TC); 400 μgL −1 sulfadiazine (SD) and sulfamethazine (SMT)) spiked into the secondary wastewater effluent (SWE) were treated by novel UV/pre-magnetized Fe 0 /PS process (UV/pre-Fe 0 /PS). TC, OTC and SMT could be completely removed within 30 min and 98.4% SD could be removed within 60 min, while less than 10%, 20% and 60% ECs could be removed by Fe 0 /PS, pre-Fe 0 /PS and UV process within 60 min. Synergetic factor values (6.1–12.3) in UV/pre-Fe 0 /PS were much larger than in UV/Fe 0 /PS (2.3–5.4) to remove various ECs, achieving 0.7 – 2.2 times enhancement in degradation rate constants and 45%–86% reduction in treatment costs. EPR spectra and scavenging tests by tert-butyl alcohol and methanol confirmed that not only faster and more SO 4 − and OH radicals were produced but also their contributions to SMT removal were enhanced. Optimization of dosage of Fe 0 (0 – 0.4 mM) and dosage of PS (0 – 0.4 mM) indicated that 0.2 mM Fe 0 and 0.2 mM PS was the optimal dosage. Meanwhile, this process not only could enhance 0.7–15.8 times degradation rate constant but also could reduce about 14.3–97.9% costs to remove various ECs compared with US/Fe 0 /PS, ozonation, VUV/UV/Fe 3+ and UV/H 2 O 2 process. Moreover, it could enhance 1.4 times of degradation rate constant and reduce about 62% cost to remove SMT in another SWE, indicating the applicability in different wastewaters. Therefore, UV/pre-Fe 0 /PS process is promising and cost-effective to remove ECs in SWEs.