ABSTRACT
A combined plasma photolysis (CPP) reactor that utilizes a dielectric barrier discharge (DBD) plasma and 207 nm UV radiation from discharge-driven KrBr* excimers was designed and constructed. Gas streams containing CS2 were treated with stand-alone DBD and CPP at atmospheric pressure. In comparison to DBD, CPP greatly enhanced the removal efficiency at the same applied voltage, waste gas concentration and gas residence time. Thus the applied voltage could be reduced to a certain extent in the plasma processing of industrial wastes. Influences of the KrBr* radiation, inlet CS2 concentration and gas residence time on CS2 removal by CPP were also studied. In addition, the likely reaction mechanisms for the removal of CS2 by CPP are suggested based on the byproducts analysis. The enhanced removal efficiency and reaction mechanisms implied that the CPP process would probably be suitable for the removal of a large number of gaseous pollutants.
Subject(s)
Air Pollutants/analysis , Air Pollution/prevention & control , Carbon Disulfide/analysis , Air Pollutants/chemistry , Air Pollutants/radiation effects , Atmospheric Pressure , Carbon Disulfide/chemistry , Carbon Disulfide/radiation effects , Electrochemistry , Gases/analysis , Photolysis , Ultraviolet RaysABSTRACT
The rate constants of reactions between the SO4*(-) radical and some common anions in atmospheric aqueous droplets e.g. Cl-, NO3-, HSO3- and HCO3- were determined using the laser flash photolysis technique. Absorption spectra of SO4*(-) and the product radicals were also reported. The chloride ion was evaluated among all the anions to be the most efficient scavenger of SO4*(-). The results may supply useful information for a better understanding of the vigorous radical-initiated reactions in atmospheric aqueous droplets such as clouds, rains or fogs.
