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International audienceThis paper deals with photocatalysis (TiO2 + UV), nonthermal plasma (NTP) and their combinations. These processes have been widely studied for isovaleraldehyde (Isoval) treatment. Isoval removal, selectivity of CO2 and CO, and ozone formation are investigated in order to evaluate the performance of the combined process. The results show that the performance of the process has enhanced and a synergetic effect is observed. On the other hand, this work aims at investigating kinetic modeling of combined process with taking into account the mass transfer step. The model is based on mass balances in three types of region: bulk region, discharge zone and solid phase which contains the photocatalyst. The oxidation in discharge and solid phases is described in two stages. Firstly, the removal of Isoval gives an equivalent intermediate (EI). Secondly, EI is oxidized into carbon dioxide (CO2) and carbon monoxide (CO). This simplified approach of removal allows for an agreement between modeling and empirical data in terms of degradation and mineralization. It also allows for the simulation of NTP and photocatalytic kinetics without knowing the plausible pathway. Moreover, the synergetic effect can be represented correctly by increasing mass transfer constant

The aim of our research is to apply experimental design methodology to the optimization of photocatalytic degradation of indole present in wastewater. Heterogeneous photocatalysis for the oxidation of organic biorecalcitrant pollutants in water is an environmental promising method. We used the response surface methodology (RSM) for the modelization and optimization of the photodegradation of indole in the presence of titanium dioxide. The effect of indole concentration, UV intensity and stirring speed on the yield of indole degradation was determined. According to the mathematic optimization of the process, the optimum point when 100% of degradation is achieved is given by the following values: UV intensity = 250 W/m 2 , stirring speed = 536.36 tr/min and initial indole concentration = 10.10 mg/l.

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