Chemical Properties and Degradation Efficiency of Radio-Frequency Plasmas In Water

To treat contaminated water, advanced oxidation technologies (AOT) utilize various precursors and processes to produce hydroxyl radicals (OH^•); species which are, because of their high oxidation potential, capable of degrading virtually any organic compound in the aqueous solution. However, in some of the AOTs, the production of OH^• can be quite limited depending on, for example, the type of the OH^• precursor (H₂O vs. H₂O₂) and the turbidity of the solution. Thus, there is a requirement for a technology that will overcome the drawbacks associated with the current AOTs and the preliminary results from this study indicate that radio-frequency (RF) plasma in water, a new “type” of plasma formed by low-voltage high-frequency (13.56 MHz) electrical discharge, could be that technology. Compared to the conventional high-voltage streamer-like discharges, the volume of the RF plasma is several times larger and the intensity of the plasma-generated UV light appears to be higher. Thus, the goal of this study is to chemically and spectroscopically characterize RF plasma and asses its efficiency for the degradation of Rhodamine B dye.