Degradation of chlorpyrifos formulation in water by the UV/H2O2 process: Lumped kinetic modelling of total organic carbon removal

Abstract

The degradation of a commercial chlorpyrifos (CP) formulation solution under the UV/H2O2 process was predicted through a lumped kinetics modelling approach (LKA). The proposed models are based on different reaction schemes that include the hydroxyl radical reaction rate with the Total Organic Carbon (TOC). TOC represents the concentration of the mixture of CP and “unknown organic matter”, both components present in CP formulation. TOC is one of the most practical parameter that can be used to quantify organic pollution in a complex matrix. A one-step model was selected and a second-order reaction rate constant between hydroxyl radical and TOC was obtained by optimization: 1.75 × 107 M−1 s−1. According to computed performance metrics, the chosen model well fitted the concentrations evolution of the reactants (TOC and H2O2). The model could be useful to predict the behaviour of reaction systems with different configuration for wastewater treatment applications.