Peroxymonosulfate activation by low-cost modified rubber during contact electrification for antibiotics efficient degradation at circumneutral pH: Mechanism and toxicity assessment

Contact electrification is known as a traditional phenomenon widely used in the green energy field, but its application in water pollution control is rarely reported. Herein, a new strategy to activate peroxymonosulfate (PMS) by contact-electro-catalysis (CEC) for antibiotics degradation was proposed and a series of contact-electrocatalysts was prepared by modified low-cost ethylene-propylene-diene-monomer rubber (EPDM). In CEC system, the optimized contact-electro-catalysts (S-EPDM/Fe-5) could degrade 91.38 % of 10 ppm TC within 30 min at a PMS dosage of 0.5 mM and pH of 6.9. O-1(2) and SO4-center dot radicals were demonstrated as main active substances for tetracycline degradation. Based on HPLC-MS results and DFT calculation, tetracycline degradation path in CEC system was proposed. The toxicity evaluation results showed that acute toxicity and bioaccumulation factor of intermediates during tetracycline degradation were significantly reduced. This work provides a new strategy and low-cost catalysts for PMS activation to promote its application in water treatment.