This work deals with the photocatalytic oxidation of toluene at room temperature and atmospheric pressure in the gas phase. The differential equations of the reactor model are solved numerically with simultaneous estimation of the model parameters. Estimation of the kinetic data is performed using a modified differential method of data analysis and a Nelder–Mead method of nonlinear optimization for parameter estimation. The reaction is performed in an annular photoreactor using UVA black light blue fluorescent lamp. The experiments are carried out at different total flow rates of the reaction feed (20–160 cm3 min−1), two different inlet concentrations of toluene (2.67 and 5.24 g m−3) and at constant relative humidity (25%). A good agreement between the experimental data and theoretical predictions is obtained, supporting the applicability of the proposed models to describe the investigated process performed in laboratory annular photoreactor.
Antioxidant and free radical scavenging activities of the extracts of sumac (Rhus coriaria) fruits and cassia (Cinnamomum cassia) cortex were studied. Plant samples were extracted with methanol:water (80:20) and an aliquot of each extract was fractionated using n-hexane and ethyl acetate. Antioxidant activities of n-hexane, ethyl acetate and water fractions were measured using Fe+2 induced linoleic acid-TBA-peroxidation reaction and the Rancimat methods. Free radical scavenging activities of the fractions were determined on 2,2-diphenyl-1-picrylhydrazyl radical (DPPH). Results were compared with those for butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT). The ethyl acetate fraction of plant materials exhibited a marked antiradical activity on DPPH.