Saturated Resin Ectopic Regeneration by Non-Thermal Dielectric Barrier Discharge Plasma

Abstract

Abstract:Textile dyes are some of the most refractory organic compounds in the environment due to their complex and various structure. An integrated resin adsorption/Dielectric Barrier Discharge (DBD) plasma regeneration was proposed to treat the indigo carmine solution. It is the first time to report ectopic regeneration of the saturated resins by non-thermal Dielectric Barrier Discharge. The adsorption/desorption efficiency, surface functional groups, structural properties, regeneration efficiency, and the intermediate products between gas and liquid phase before and after treatment were investigated. The results showed that DBD plasma could maintain the efficient adsorption performance of resins while degrading the indigo carmine adsorbed by resins. The degradation rate of indigo carmine reached 88% and the regeneration efficiency (RE) can be maintained above 85% after multi-successive regeneration cycles. The indigo carmine contaminants were decomposed by a variety of reactive radicals leading to fracture of exocyclic C=C bond, which could cause decoloration of dye solution. Based on above results, a possible degradation pathway for the indigo carmine by resin adsorption/DBD plasma treatment was proposed.

Degradation of Indigo Carmine in Alkaline Dye-Mediated Direct Carbohydrate Fuel Cell

“…Significant work has been performed demonstrating the oxidative chemical pathways and catalytic removal of indigo carmine from water streams. [38][39][40] Isatin sulfonic acid is the first likely product produced during the oxidation of reduced indigo carmine. [38][39][40] Following that initial reaction, the isatin sulfonic acid undergoes oxidation, resulting in an isatin molecule and a sulfate ion liberating two electrons (Fig.…”

“…[38][39][40] Isatin sulfonic acid is the first likely product produced during the oxidation of reduced indigo carmine. [38][39][40] Following that initial reaction, the isatin sulfonic acid undergoes oxidation, resulting in an isatin molecule and a sulfate ion liberating two electrons (Fig. 8).…”

“…Isatin oxidative degradation pathways have been shown to produce phthalic anhydride, anthranilic acid, and oxamic acid and benzene, depending on the oxidation scheme and catalysts used. [38][39][40] In this case, given the high affinity of platinum for amines and the energetic favourability (−6.75 kJ.mol −1 ), it is likely that isatin breaks down into ammonia and phthalic anhydride. 31 The phthalic anhydride is likely then broken down further into smaller molecules of various stoichiometries.…”

Photocatalysts for Organics Degradation

“…Integrated systems able to solve the aforementioned issues in a single step could be less expensive and more efficient, but their development requires advancements from the point of view of both materials and the process. In this Issue, a system consisting of integrated resin adsorption/Dielectric Barrier Discharge (DBD) plasma regeneration was proposed to treat some textile dyes, showing that the DBD plasma could maintain the efficient adsorption performance of the resin while degrading the adsorbed dye [1]. Some AOPs imply the presence of catalyst, especially in photocatalytic processes: the goal of photocatalysis is to find efficient and stable materials (under the reaction conditions), which are able both to stabilize excitons (i.e., the generated electron/hole pairs) and to exploit solar light.…”