Removal of atorvastatin in water mediated by CuFe2O4 activated peroxymonosulfate

Atorvastatin (ATV) has been widely detected in wastewater treatment plant and aquatic environment. Limited mineralization ratio of ATV in current wastewater treatment processes may result in the accumulation of its transformation intermediates in effluent and cause additional ecological risk to the environment. In this study effectiveness of peroxymonosulfate (PMS) activated by CuFe2O4 on the degradation of ATV in water were examined. Complete removal of ATV was achieved by using 40 ppm CuFe2O4 and 25 mu mol dm(-3) PMS. Eight intermediates were identified and four degradation pathways were proposed. The distribution of major intermediates ATV lactone (P-541), hydroxylated ATV lactone (P-557) and the pyrrole ring-open intermediate (P-416) were monitored with different PMS dosages. As PMS concentration increased from 25 to 150 mu mol dm-3, the main intermediates accumulated were evolved from P-541 and P-557 to P-557 and P-416, and all intermediates were completely degraded with 750 mu mol dm(-3) PMS. 61.72% TOC removal was achieved at pH 7.0 with 100 ppm CuFe2O4 and 3 m mol dm(-3) PMS, which indicated that ATV could be well mineralized if PMS and CuFe2O4 dosages were reasonably used. Overall, this study provided practical knowledge for ATV removal by CuFe2O4/PMS at ambient temperature.