Removal of Fluticasone Propionate and Clobetasol Propionate by Calcium Peroxide: Synergistic Effects of Oxidation, Adsorption, and Base Catalysis

Ai Zhang 1

Xueyan Yin 1

Xue Shen 1

Yanan Liu 1, 2, Email

1 College of Environmental Science and Engineering, Donghua University, 2999 North Renmin Road, Shanghai 201620, China
2 Shanghai institute of pollution control and ecological security, Shanghai 200092, China

Abstract

Performance of calcium peroxide (CaO2 ) in fluticasone propionate (FP) and clobetasol propionate (CP) removal was investigated. The removal mechanisms in CaO2 treatment were explored. Specifically, degradation intermediates of FP and CP in CaO2 treatment were firstly identified. CaO2 treatment can be a practical and effective technology for FP and CP removal because of its synergistic effects in oxidation, adsorption, and base catalysis. Over 99.4% and 84.4% of FP and CP could be removed in 0.5 min at CaO2 dosage of 0.1 - 4 g L-1 at initial pH of 7, respectively. HO• was the dominant radicals responsible for FP and CP degradation in CaO2 oxidation while •O2 - also accelerated the removal. The suitable increase of solution pH (< 9) by Ca(OH)2 released from CaO2 and the adsorption effects of CaO2 particles also contribute to FP and CP removal. CaO2 treatment remained effective in complex water matrix with the presence of humic acid (HA) and common anions except for HCO3 -. Moreover, nine intermediates were revealed for the first time during CaO2 treatment indicating the decrease of glucocorticoid toxicity by CaO2 treatment.

Removal of Fluticasone Propionate and Clobetasol Propionate by Calcium Peroxide: Synergistic Effects of Oxidation, Adsorption, and Base Catalysis