Degradation of styrene from waste gas stream by advanced oxidation processes

Abstract

Waste-air treatment is experimentally investigated by advanced oxidation processes utilizing UV irradiation combined with ozone and hydrogen peroxide. The effect of operating parameters, such as an initial concentration of styrene and flow rate of gas, on the removal of styrene is studied in a photochemical pilot plant unit. The conversion of styrene decreases with an increasing initial styrene concentration and with a decreasing retention time (higher flow rate) of waste gas. The highest conversion of styrene (87%) is achieved under lower initial styrene concentration (100 ppm) and lower flow rate (42m(3) h(-1)). The energy per order is also calculated for the advanced oxidation process. Electrical energy per order is calculated for all the experimental conditions and it was found that the energy consumption is of about 0.070 kW h m(-3) per order, for the 87% styrene removal at 100 ppm of initial styrene concentration and 42m(3) h(-1) flow rate. The combination of UV irradiation and ozone is significantly more efficient with lower electrical energy need per order in comparison with combination of UV irradiation and hydrogen peroxide. Therefore, the advanced oxidation process represents a promising treatment technology for the management of waste-air and the pilot plant unit designed for high flow rates of waste-gas streams is suitable for an industrial use.