Photocatalytic degradation of indole in a circulating upflow reactor by UV/TiO2 process--influence of some operating parameters.

The present work involves the photocatalytic degradation of indole on a recirculating reactor. The effects of various factors as initial concentration of indole, catalyst-loading, pH, agitation and flow rate of the solution on the photodegradation were examined. The experimental results indicate that the optimal pH for indole elimination is about 6-7; the effect of catalyst loading shows an optimal value (1g/L) which is necessary to degrade indole; the increase of recirculating rate leads to a decrease of degradation rate due to the reduction of the residence time; the agitation speed has a slight influence on the indole degradation by improving the mass transfer step. Finally, L-H model was used to fit experimental results concerning the influence of experimental data. L-H model constants' were determined also.

Optimization of the indole photodegradation on supported TiO(2): influences of temperature, concentration, TiO(2) amount and flow rate.

This work describes the photodegradation of aqueous indole solutions by using TiO(2) supported on cellulose fibres. Four parameters were studied: the indole concentration; the TiO(2) amount; the temperature and the flow rate. Central composite experimental design was used to determine the influences of the parameters on the indole degradation percentage. We demonstrate that in our experimental domain the quasi complete degradation of indole is in all cases reached and more interestingly that it is possible to find unique values of TiO(2) amount and flow rate leading to optimised photodegradation of indole in the studied domains of temperature and indole concentration.