Development of an Ambient Air Flow Rotating Arc Jet for Low-Temperature Treatment

Abstract

For low-temperature atmospheric pressure plasma treatment applications, we developed a novel rotating arc jet operated using various gases, including ambient air. We demonstrate the operation of plasma via the injection of various gas mixtures and tune operation parameters to achieve a low-temperature gas output from the arc jet. The rotating arc jet has an efficiency two orders of magnitude higher in the generation of reactive oxygen and nitrogen species than commercially available conventional nonequilibrium atmospheric pressure plasma jets operated with He or Ar gases. The high concentration of reactive species and use of ambient air as a process gas is promising for biomedical and agriculture applications. This work is a step toward the commercial use of plasma jets operated with ambient air. INDEX TERMSReactive oxygen and nitrogen species (RONS), Rotating arc jet, atmospheric-pressure plasmas, UV absorption, Escherichia coli.

Direct Treatment of Liquids Using Low-Current Arc in Ambient Air for Biomedical Applications

“…Recently, treatment of liquids using various atmospheric pressure plasmas has attracted much attention owing to its wide range of possible applications, such as synthesis of nanocarbons and nanoparticles, sterilization of microorganisms, growth enhancement of plants, plasma farming, cancer therapy, and water purification [1][2][3][4][5][6][7][8][9][10][11][12][13]. Typically, low-temperature nonequilibrium atmospheric pressure plasma jets (NEAPPJs) or dielectric barrier discharges (DBDs) are used for activation of liquids by plasma [5,[12][13][14][15][16].…”

“…The low efficiency, the requirement of pure gases, and the limited volume of liquid that can be treated make plasma-treated water (PTW) expensive and its use in medicine and agriculture impossible. The most promising method for effective and low-cost production of PTW is treating liquids with high-density plasma generated by using air as a process gas [3,18,[23][24][25][26]. Furthermore, it may be possible to scale up production and reduce the cost of PTW by applying plasmas generated in ambient air to treat a continuous flow of liquid.…”

“…For that reason, thermal and warm plasmas could be used for irradiation of medium following the cooling of PTM and use in biomedical applications. Considering the high efficiency of arc or gliding arc discharges in the decomposition of CO 2 and other gases and the effective production of RONS, this type of discharge could also be employed for the effective generation and fast delivery of RONS to the target liquid [3,25,33,34]. There are many works on the generation of arc and discharges and other types of plasmas inside or on the surface of highly conductive liquids using various configurations and experimental conditions, however, generation of high-density plasma transferred to the surface of deionized water (DI) or other liquids with low electrical conductivity in ambient air is still challenging owing to the relatively high electric currents required for the stable generation of the discharge [10,11,18,23,[35][36][37][38][39].…”

Scalable Treatment of Flowing Organic Liquids Using Ambient-Air Glow Discharge for Agricultural Applications

“…− , NO 3 − , and dissolved oxygen O 2aq . All of these species have strong absorption in the deep ultraviolet and absorption spectrum of the liquid at a wavelength range between 190 and 400 nm, and could provide information about the concentrations of each species, as was reported elsewhere [32,33,45]. An additional advantage of DUV absorption spectroscopy is the short time required for measurement (below 5 min), and the possibility of sample analysis without special preparation (e.g., filtering in the case of HPLC).…”

“…Low energy efficiency, the requirement of noble gases, and the limited volume of liquid that can be treated make a plasma-activated medium (PAM) expensive, and its use in practical agriculture applications impossible [18]. Considering the cheapest price of ambient air compared to other gases, and the high concentration of nitrogen and oxygen required for RONS production, the most effective way to reduce the cost of plasma treatment is the use of ambient-air high-density plasmas for liquid treatments [16,[40][41][42][43][44][45][46][47][48][49]. Energy-effective treatment could be achieved by employing the plasma treatment of electrosprayed liquid; however, the reported flowrate for this system is below 1 L/min, which could result in problems with scaling PAM production [16].…”