Curbing chlorine disinfection byproduct formation with a biomimetic FeTAML oxidation catalyst

Abstract

We demonstrate, by bench-scale chlorination of local tap water containing phenol (16 μM, 1.5 ppm) as a model organic micropollutant, that the [Fe(TAML)]⁻ catalyst (TAML = tetra amido macrocyclic ligand) increases the rate of phenol decomposition and suppresses the build-up of chlorophenol disinfection byproducts. Specifically, significantly lower concentrations of trihalomethanes (1.0–2.1 ppb) were formed in the presence of [Fe(TAML)]⁻ compared to those formed in the absence of the catalyst (39–78 ppb). Hydrophobic disinfection byproducts (1–2000 ppb) were monitored in real-time and without any sample preparation using membrane inlet mass spectrometry. This work encourages the incorporation of biomimetic iron catalysts into existing chlorine disinfection processes to harness the oxidative power of chlorine through oxygen- or hydrogen-atom transfer reactions instead of the problematic halogenation reactions which yield disinfection byproducts.