Dense Medium Plasma-Plasma-Enhanced Decontamination of Water of Aromatic Compounds

Artificially contaminated water with aromatic compounds, including benzene, ethylbenzene, and xylenes, was exposed to dense medium plasma (DMP) environments in the presence of oxygen. This original plasma technique allows the volume exposure of liquid media to nascent plasma species under atmospheric pressure conditions. Analytical data resulting from gas chromatographic/mass spectroscopic evaluations of contaminated and plasma-exposed water, indicated that prior to any optimization the DMP technology can reduce contamination levels of 600–1,000 ppm to ppb values in treatment times as low as 1 min. It is suggested that hydroperoxide molecules generated as a result of the interaction of plasma-activated oxygen and water molecules, might play an essential role through the interaction of nascent OH free radicals with the contaminant molecules in the decontamination process. The reaction products (hydrocarbons and oxidized derivatives) have a significantly lower concentration relative to the starting contaminants (at least two to three orders of magnitude lower concentrations). This original plasma technology opens up new highways for efficient decontamination of water both under batch-type and continuous-flow system modes.