Kinetics modeling of a mixture of pollutants in water using UV/H2O2 process

M.L. MARIANI; R. BRANDI; A. CASSANO; C.S. ZALAZAR

Rio de Janeiro

Encuentro; VI Encontro sobre Aplicações Ambientais de Processos Oxidativos Avançados; 2011

We report a mathematical model for representing the time evolution of a mixture of pollutants in water using the UV/H2O2 process. The employed reactants were dichloroacetic acid (DCA) - a typical by product of chlorine disinfection - and formic acid, a very simple model compound. The kinetic model must be independent of the shape, size and configuration of the laboratory reactor in order to be apt for scaling up purposes.The experimental device consists of a cylinder sealed with two parallel, flat windows made of quartz. Irradiation was produced with low-pressure mercury vapor lamps (253.7 nm). The reactor is placed inside a recycle with includes: i) the centrifugal pump ii) a heat exchanger for temperature control iii) a storage tank (VTank=2000 cm3).Experiments where carried out changing the following variables: (i) hydrogen peroxide/pollutant mixture initial concentration ratio, ii) initial DCA and Formic Acid concentration, iii) incident radiation at the reactor wall. Using de mass action law and the micro steady state approximation, a kinetic model was developed. This is the first step for the proposal of a sounded mathematical modeling for the degradation reaction kinetics of more complex mixtures.