Efficient removal of trace-level bisphenols in drinking water using the Mn(VII)/CaSO₃ process

Area of Science:

• Environmental Chemistry
• Water Treatment Technologies

Background:

• Bisphenols are emerging pollutants found in drinking water at ng/L to μg/L levels.
• Previous studies on bisphenol degradation used much higher concentrations (mg/L), limiting real-world applicability.
• Effective removal of bisphenols at environmentally relevant concentrations remains a challenge.

Purpose of the Study:

• To investigate the efficacy and mechanism of removing 18 trace-level bisphenols from drinking water.
• To evaluate a calcium sulfite (CaSO3)-coupling permanganate (Mn(VII)/CaSO3) process for bisphenol removal.
• To assess the process's performance under environmentally relevant conditions.

Main Methods:

• Utilized a calcium sulfite (CaSO3)-coupling permanganate (Mn(VII)/CaSO3) process.
• Tested the removal of trace-level bisphenols (1.0 μg/L) at pH 6.0-8.5.
• Employed quantitative structure-activity relationship (QSAR) analysis and identified reactive manganese species.

Main Results:

• The Mn(VII)/CaSO3 process effectively removed trace-level bisphenols (1.0 μg/L) within pH 6.0-8.5.
• Bisphenol degradation rates positively correlated with average polarizability.
• Reactive manganese species were identified as the primary agents of bisphenol degradation.
• The process demonstrated resistance to water matrix interference and effectiveness in real water samples.

Conclusions:

• The Mn(VII)/CaSO3 system is a promising pre-oxidation process for controlling trace-level bisphenols in drinking water.
• The process effectively reduces potential risks associated with bisphenol contamination.
• This method offers a viable solution for bisphenol removal at environmentally relevant concentrations.