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Aromatic volatile organic compounds (VOCs) proved to have enhanced polluting behavior upon the atmosphere and human health. Their catalytic destruction is an alternative for environmental pollution reduction in the case of gaseous emissions with low contents of VOC. In this paper, an experimental study is presented, concerning the conversion of benzene and its mono-halogenated derivatives on SCR-DeNOx (V 2 O 5 -WO 3 /TiO 2 ) commercial catalyst, specific for the reduction process of nitrogen oxides. The catalytic oxidation was carried out at temperatures ranged between 423 0 K -623 0 K in different reaction environments (air, water vapors and halogenated acids) and for low concentrations of aromatic organic pollutants (< 100 ppm). The catalytic conversion of aromatic organic volatile compounds increases with temperatures and is influenced by the presence of water vapors and halogenated acids. It can reach values of above 75%, for a temperature of 623 0 K. The reaction of catalytic oxidation is incomplete and leads to CO formation.

Monolithic reactors play an important role in the integrated approach to environmental protection, especially in air pollution abatement. Mathematical modelling of catalytic reactors has become a key procedure in the design, development and optimisation of many industrial processes. The objective of this study was the modelling and simulation of the catalytic oxidation of volatile organic compounds by a commercial V2O5-WO3/TiO2 honeycomb catalyst, specific for the SCR-DeNOx process in high-dust flue gases from stationary incineration. The mathematical model is developed for the numerical simulation of a tubular plug flow reactor, using mass balance equation to predict results for benzene conversion under isothermal conditions.

In recent years, the release of volatile organic compounds (VOCs) has received much attention. Catalytic oxidation of VOCs, found in small concentration in industrial gas emissions constitutes an alternative for environmental pollution reduction. In this paper, a comparative study regarding the non-catalytic and catalytic oxidative destruction of non-halogenated or halogenated C 6 hydrocarbons (C 6 H 14 , C 6 H 12 , C 6 H 6 , Cl-C 6 H 5 , Br-C 6 H 5 ), is presented. Catalytic oxidation was studied in the presence of industrial V 2 O 5 -WO 3 /TiO 2 (0.53 %wt. V 2 O 5 ) catalyst, specific for SCR-DeNOx processes in high-dust system. Oxidative destruction was carried-out at 150 -350 0 C in dry and, respective, humid air stream (5 %vol. H 2 O), for low concentration of hydrocarbons in gas phase (< 100 ppm). The catalytic oxidation of hydrocarbons is partial, apart of CO 2 , also CO being detected at the end of the reaction. Study of noncatalytic oxidation of hydrocarbons showed that independent of the presence of water vapors, aromatic hydrocarbons do not react in gas phase. The acyclic hydrocarbons react in gas phase starting with the temperature of 300 0 C.

Refractory organic compounds (priority pollutants) are difficult to remove from industrial wastewaters by conventional methods and, especially in the case of biological treatment, these compounds may slow down or even stop the microorganisms activity. Heterogeneous photocatalysis may be considered a viable alternative for the removal of refractory organics due to several important advantages such as: complete mineralization or formation of more readily biodegradable intermediates when complex organic compounds are treated, no need of auxiliary chemicals, no residual formation, easily operation and maintenance of the equipment. This paper presents a literature survey of the research conducted in the field of heterogeneous photocatalysis, providing information on the possibilities and efficiencies encountered in the application of this process for industrial wastewater treatment for the removal of different types of refractory organic compounds. The basic fundamental principles are described, as well as the influence of the main parameters governing the heterogeneous photocatalytic process such as: wavelength, mass of catalysts, type and initial concentration of refractory organic contaminants, type of charge-trapping species, initial pH, temperature, light intensity. The possibilities to oxidise the organic compound from different industrial wastewaters are also reviewed in order to identify the active catalysts and the operating conditions, but also to investigate the correlations between all factors influencing the photocatalytic process.