Decomposition of Organic Compounds in Water by Direct Contact of Gas Corona Discharge:  Influence of Discharge Conditions

Abstract

Water purification experiments to decompose phenol, acetic acid, and Rhodamine B in water were conducted using a direct contact of gas corona discharge to the water surface. It was shown that O2 was important in the gas phase for the degradation process, and the negative corona showed higher degradation rates than the positive corona. It was found that the organic contaminants can effectively be decomposed by the present method without pH adjustment. The experimental results indicated that there were optimized values in the O2 concentration, the gas resident time above the water, and the cathode−anode gap. It was also indicated that the O2/CO2 mixture showed a higher degradation rate than the O2/N2 mixture for the gas phase. As the degradation mechanism, the uncharged short-lived radicals are considered to be important.

Influence of Oxygen and Dissolved Inorganic Additives on the Removal of Gaseous Acetylaldehyde by Use of a Wetted‐Wall Corona Discharge Reactor

“…In contrast, it was found in previous work that HNO 3 does not significantly affect the absorptivity of acetaldehyde [13]. In fact, HNO 3 was produced in water during the corona operation, leading to a decrease in the pH of water [22,23]. When the current is 0.1 mA, the pH of water decreased from around 6±6.5 to 5, corresponding to 10 ±5 mol/L HNO 3 .…”

Characterization of plasma-induced phenol advanced oxidation process in a DBD reactor

“…There is currently much ongoing research to exploit and apply electrical discharges for water purification [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. Many different prototype reactors have been developed, including systems in which the discharge occurs into [2][3][4][5] or above the liquid [6][7][8][9], as well as hybrid reactors, which utilize both gas phase non-thermal plasma and direct liquid phase corona-like discharge in the water [10,11].…”

“…Many different prototype reactors have been developed, including systems in which the discharge occurs into [2][3][4][5] or above the liquid [6][7][8][9], as well as hybrid reactors, which utilize both gas phase non-thermal plasma and direct liquid phase corona-like discharge in the water [10,11]. In addition reactors have been reported in which the solution to be treated is supplied into the discharge area as an aerosol [12] or as a falling-water film [13,14].…”

Promotion of crystal growth rate in aqueous solution by direct contact with gas corona discharge

“…Nowadays, there are a considerable number of researches to use gas discharge to some industrial applications such as plasma chemical deposition [1], surface modification [2], gas purification [3][4][5], and water purification [6][7][8][9][10][11][12]. To achieve these processes, highly-reactive gas radicals induced by reactions of accelerated electrons with gas molecules are important.…”