Quantifying evolving toxicity in the TAML/peroxide mineralization of propranolol

Yogesh Somasundar; Abigail E Burton; Matthew R Mills; David Z Zhang; Alexander D Ryabov; Terrence J Collins

doi:10.1016/j.isci.2020.101897

Quantifying evolving toxicity in the TAML/peroxide mineralization of propranolol

iScience. 2020 Dec 7;24(1):101897. doi: 10.1016/j.isci.2020.101897. eCollection 2021 Jan 22.

Authors

Yogesh Somasundar¹, Abigail E Burton¹, Matthew R Mills¹, David Z Zhang¹, Alexander D Ryabov¹, Terrence J Collins¹

Affiliation

¹ Institute for Green Science, Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA 15213, USA.

Abstract

Oxidative water purification of micropollutants (MPs) can proceed via toxic intermediates calling for procedures for connecting degrading chemical mixtures to evolving toxicity. Herein, we introduce a method for projecting evolving toxicity onto composite changing pollutant and intermediate concentrations illustrated through the TAML/H₂O₂ mineralization of the common drug and MP, propranolol. The approach consists of identifying the key intermediates along the decomposition pathway (UPLC/GCMS/NMR/UV-Vis), determining for each by simulation and experiment the rate constants for both catalytic and noncatalytic oxidations and converting the resulting predicted concentration versus time profiles to evolving composite toxicity exemplified using zebrafish lethality data. For propranolol, toxicity grows substantially from the outset, even after propranolol is undetectable, echoing that intermediate chemical and toxicity behaviors are key elements of the environmental safety of MP degradation processes. As TAML/H₂O₂ mimics mechanistically the main steps of peroxidase catalytic cycles, the findings may be relevant to propranolol degradation in environmental waters.

Keywords: Chemical Engineering; Environmental Chemical Engineering; Environmental Chemistry; Green Chemistry.