Facilitated Prediction of Micropollutant Degradation Via UV-AOPs in Various Waters by Combining Model Simulation and Portable Measurement

The degradation of micropollutants in water via ultraviolet (UV)-based advanced oxidation processes (AOPs) is strongly dependent on the water matrix. Various reactive radicals (RRs) formed in UV-AOPs have different reaction selectivities toward water matrices and degradation efficiencies for target micropollutants. Hence, process selection and optimization are crucial. This study developed a facilitated prediction method for the photon fluence-based rate constant for micropollutant degradation (k'p,MP) in various UV-AOPs by combining model simulation with portable measurement. Portable methods for measuring the scavenging capacities of the principal RRs (RRSCs) involved in UV-AOPs (i.e., HO', SO4'-, and Cl') using a mini-fluidic photoreaction system were proposed. The simulation models consisted of photochemical, quantitative structure-activity relationship, and radical concentration steady-state approximation models. The RRSCs were determined in eight test waters, and a higher RRSC was found to be associated with a more complex water matrix. Then, by taking sulfamethazine, caffeine, and carbamazepine as model micropollutants, the k'p,MP values in various UV-AOPs were predicted and further verified experimentally. A lower k'p,MP was found to be associated with a higher RRSC for a stronger RR competition; for example, k'p,MP values of 130.9 and 332.5 m2 einstein-1, respectively, were obtained for carbamazepine degradation by UV/H2O2 in the raw water (RRSC = 9.47 x 104 s-1) and sand-filtered effluent (RRSC = 2.87 x 104 s-1) of a drinking water treatment plant. The developed method facilitates process selection and optimization for UV-AOPs, which is essential for increasing the efficiency and cost-effectiveness of water treatment. (c) 2023 THE AUTHORS. Published by Elsevier LTD on behalf of Chinese Academy of Engineering and Higher Education Press Limited Company. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).