Abatement of odor pollution from municipal waste by dielectric barrier discharge plasma process

Odors mainly containing styrene produced by municipal waste are highly toxic to human health; therefore, their safe elimination is extr emely important. In this paper, a wire-plate dielectric barrier discharge (DBD) reactor was investigated. The parameters used in the evaluation included styrene removal efficiency, specific energy density (SED), carbon balance, products and byproducts distribution. Experimental results indicated that styrene removal efficiency as high as 100% and 89.4% can be achieved at 175J/L with the gas flow rate of 360ml/min and 720ml/min respectively. It was demonstrated that the removal efficiency decreased with increasing the initial styrene concentration and the discharge gap. The optimum humidity was up to 0.5%, which suggested that 0 atom and OH radical from water vapor were related with enhanced apparent styrene conversion. The major gaseous products detected by GC and GC-MS were CO, CO2 and hypnone, as well as minor byproducts such as phenylethanol and phenylacetaldehyde. The behaviors of styrene in DBD reactor were complicated resulting from the oxidation and polymerization reactions occurred simultaneously and competed with each other. Increasing electrical energy density and temperature favor the styrene oxidation, whereas the higher the initial concentration, the higher the probability of polymer formation. A second-order kinetic model expression was developed with respect to the reactive plasma species and contaminant concentration. Degradation rate constant was determined for styrene and experimental data were fitted to the proposed model.