Peroxymonosulfate-assisted electrolytic oxidation/ coagulation combined with ceramic ultrafiltration for surface water treatment: Membrane fouling and sulfamethazine degradation

An integrated peroxymonosulfate (PMS)-assisted electrolytic oxidation/coagulation (EO/EC) and ceramic ultrafiltration (UF) process was applied for antibiotic removal in surface water. Stable permeation was achieved in the case of surface water containing sulfamethazine (SMZ) (0–800 μg/L), and the optimum conditions appeared to be an electrical current (I) of 0.2 A, electrolysis time of 60 s, pH 7.5 (nearly 0.56 mg/L Fe²⁺, considering the pH value of the initial solution) and PMS dosage of 100 μM. During the PMS activation process, SMZ and organic matter were degraded by sulfate radicals (SO₄·^-) or hydroxyl radicals (·OH), which was confirmed by electron paramagnetic resonance spectroscopy (EPR), and scanning electron microscopy (SEM) and X-ray energy-dispersive spectroscopy (EDS) indicated that the ceramic UF membrane could effectively retain coagulants containing C, S and Fe. Moreover, PMS-assisted electro-oxidation/coagulation pretreatment could generate larger coagulated aggregates (206–275 μm) regardless of the humic acid (HA) (0–20 mg/L) and kaoline particle (0–100 mg/L) content of surface water, thus significantly decreasing the fouling rate. In particular, this process could achieve stable permeation and retain better filtration performance in the case of high antibiotic and organic matter contents in real surface water treatment. This electrically powered process could be used to treat micro-polluted water in remote regions.