Modeling and validation of a modular multi-lamp photo-reactor for cetylpyridinium chloride degradation by UV and UV/H2O2 processes

UV-C assisted disinfection processes are among the well-known tertiary processes for water reuse, wastewater reclamation and domestic water disinfection. However, treated wastewaters normally contain several organic compounds and pollutants that can be partially degraded under UV-C irradiation to different by-products, often more toxic than their parent compounds, and/or, for longer treatment times, completely mineralized. For this reason, kinetic modeling of pollutants degradation in UV-C assisted processes is of crucial importance in plants design. This work aims to the characterization of a reactor configuration consisting of 6 lamps placed following a symmetric hexagonal geometry. Specifically, a mathematical model is proposed to estimate the mean optical length and degradation kinetics for UV-C and UV-C/H2O2 processes. The model has been tested with different reference organic compounds and represents a significant characterization of a modular geometric unit used in a great variety of applications. Finally, the characterized reactor was used to estimate the quantum yield of direct photolysis at 254 nm () and kinetic constant of reaction with hydroxyl radical of cetylpyridinium chloride (CPC) , an emerging pollutant of wide interest.