| Plasma, the fourth state of matter, consists of a collection of radicals, active atoms and molecules, free-moving electrons, and other species. Some components in plasma are very active species, which can induce novel chemical reactions. Energy is needed to strip electrons from atoms to produce plasma. The energy can be of various origins: thermal, electrical, or light (ultraviolet light or intense visible light from a laser). Low-temperature glow discharge plasma was sustained by d.c. glow discharge between the anode and the surface of the electrolyte. Its remarkable characteristic was the strong deviation of the chemical yields from that expected on the basis of Faraday's law.In the reaction zone within the plasma around the anode, H2O vapor molecules was ionized or activated, and then bombard each other to break up by charge transfer. The ultimate result was the production of ·OH radicals and sometimes ·H radicals. On the other hand, in the liquid-phase reaction zone near the plasma-anolyte interface, several liquid H2O molecules broke up into ·H,·OH and HO2· by being bombarded by each H2O+gas from the anodic plasma. As a mixture of the active species ·OH, ·H, H2O2 and H2O+gas diffused out of the primary zone that was called plasma layer and into the bulk electrolyte, they could interact among themselves and with any active substrate in the solution. Since ·OH is one of the strongest oxidants that could oxidize many organic pollutants into fatty acids, carbon dioxide or simple inorganic compound, low-temperature glow discharge plasma can be applied in the treatment of organic contaminants in aqueous solution.On the basis of above facts and ideas, a series of research work have been carried out, concerning the low-temperature plasma degradation of organic contaminants. All of these researches and the relevant results are reported in the following five parts.Chapter I Review on plasma, its application and chemical effectsThe application and chemical effects of low-temperature glow discharge plasma in different mediums are described in this part. The discharge characteristics and themechanisms on chemical process about glow discharge plasma are also reviewed. And the perspective of low-temperature glow discharge plasma was discussed to the point.Chapter II Plasma degradation process of ((Naphthol in aqueous solutionDegradation of ((naphthol induced by plasma in aqueous solution was investigated. Some predominant products were analyzed by high performance liquid chromatography (HPLC). A path of ((naphthol disappearance caused by plasma was proposed according to the detected intermediate products. The plasma degradation of ((naphthol proceeded in a pathway as follows: hydroxylation of naphthol ring; oxidative ring scission resulting in o-phthalic acid; removing carboxyl from o-phthalic acid leading to o-hydroxylbenzoic acid; further ring cleavage forming dicarboxylic acid; and ultimate oxidation to inorganic carbon. Under normal conditions, the degradation of o-phthalic acid was more difficult than ((naphthol. Chapter III The kinetic behavior of plasma degradation of acridine orange with contact glow discharge electrolysis The kinetic behavior of plasma degradation of acridine orange (AO) with contact glow discharge electrolysis (CGDE) was investigated under different mediums, pH, and voltages. From the variation of AO concentration with the reaction time, it was demonstrated that the oxidation would be the first-order reaction. The applied voltage was the most predominant factor. The rate constant increased with the increase of applied voltage. And the rising of temperature increased the rate constant slightly. The concentration and pH (5.00-8.00) had no appreciable effect on the rate constant in the degradation process of AO. And Fe2+ had the remarkable catalytic effect on it.Chapter IV Oxidative degradation of cationic red induced by plasma with contact glow discharge electrolysisThe Oxidative Degradation of Cationic Red (GTL) with contact glow discharge electrol...
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