Effect of various reagents on the decomposition of endocrine disruptors by ozonation: A detailed study

Estrogenic hormones and hormone-mimics are chemical compounds widely used in the pharmaceutical and petrochemical industries. They present in the aqueous environment with increasing concern due to their adverse impact on aquatic life, and long-term risk to human health. This study investigates the decomposition of two estrogenic hormones progesterone (P4) and 17? estradiol (E2) and a hormone-mimic bisphenol A (BPA) by ozonation. For the first time, this study reveals the catalytic role of phosphate ions in triggering ozone side reactions with interfering oxidants, reductants, and organic components, resulting in a diminished selectivity of the ozone towards direct reaction with the target compounds. Complete mineralization of the studied compounds was confirmed by GC?MS and TOC measurements. A novel relative activity determination tool was developed and applied to show sequential reduction in the relative estrogenic activity with increasing ozone concentrations, until ultimately achieving near complete inactivation of the studied compounds. The studies of decomposing the targets in wastewater showed that the rate constants and removal efficiencies are moderately reduced, and complete removal is still achieved with higher doses. The findings of this study will provide important insights and directions to water treatment agencies and future large scale studies.

Automated summary

Estrogenic hormones and hormone-mimics pose a threat to aquatic life and human health in aqueous environments. Ozonation has been shown to effectively degrade these compounds, with phosphate ions playing a catalytic role. A novel relative activity determination tool can assess near complete inactivation of the target compounds with increasing ozone concentrations.