Study of hydroxyl and nitrite radicals concentration in plasma-activated water by photoluminescence spectroscopy

Abstract

Abstract The atmospheric pressure plasma in water has numerous applications, including utilizing reactive species in the dye degradation process for polluted water remediation. In the current study, an air plasma jet generated atmospheric pressure plasma, transporting reactive oxygen and nitrogen species (RONS) onto the solution surface, such as OH and NO2 radicals, which immediately developed in an aqueous solution. The identification and concentration of radicals are determined using photoluminescence spectroscopy (PL) and irradiation over the surface of an aqueous solution. Based on the reaction between hydroxyl ions and terephthalic acid, fluorimetric methods for hydroxyl ions determination are developed. In addition, 2,3-diamino naphthalene was selected for the nitrite reaction. The jet nozzle-to-solution-surface distance, treatment time, and carrier air flow rate substantially impacted determining the radical’s concentration in aqueous solution.