Quantifying evolving toxicity in the TAML/peroxide mineralization of propranolol

Area of Science:

• Environmental Chemistry
• Toxicology
• Water Treatment Technologies

Background:

• Oxidative water purification of micropollutants (MPs) can generate toxic intermediates.
• Assessing the evolving toxicity of chemical mixtures during degradation is crucial for environmental safety.

Purpose of the Study:

• To develop and demonstrate a method for projecting evolving toxicity based on pollutant and intermediate concentrations.
• To analyze the TAML/H2O2 mineralization of propranolol as a case study.

Main Methods:

• Identification of key intermediates using UPLC/GCMS/NMR/UV-Vis.
• Determination of catalytic and noncatalytic oxidation rate constants via simulation and experiment.
• Conversion of predicted concentration-time profiles to evolving composite toxicity using zebrafish lethality data.

Main Results:

• The method successfully projected evolving toxicity during propranolol degradation.
• Toxicity increased significantly from the start, persisting even when propranolol was undetectable.
• Intermediate chemical behavior is a critical factor in the environmental safety of MP degradation.

Conclusions:

• The developed approach provides a framework for assessing the environmental safety of oxidative MP degradation processes.
• Findings are relevant to propranolol degradation in environmental waters, particularly concerning TAML/H2O2 systems mimicking peroxidase cycles.