Application Of Low Temperature Plasma-Degradation Of Phenol Derivatives

Plasma, which consists of positive and negative ions and electrons, as well as neutral species, is commomly called as the fourth state of matter. It exists widely in nature. There are two kinds of plasmas that are basically used in industry and laboratory, i.e. the high-temperature and low-temperature plasmas or gas discharges. In this dissertation, a brief review has been made firstly, then, we put our focus on the application in chemistry fields, such as degradation of phenol derivatives in aqueous, polymerization starter in the reaction of poly (acrylamide-co-acrylic acid) . For improving the efficiency in the practical use, some of setups are designed or modified. The detail contents were submitted to the Chinese Patent. The whole paper includes four parts.Part I ReviewThis part gives a mini-rview of gas discharge plasmas in a broad perspective. Including analytical application (for example, glow discharges, ICPs and microwave discharges). Various types of existing gas discharge plasmas and their working principles were explained, as well as their most important applications were outlined. The basic concept of contact glow discharge electrolysis (CGDE), the possible mechanism affected on chemical process and the future application are also discussed.Part II Modification of contact glow discharge electrolysis reactorContact glow discharge electrolysis [CGDE] was regarded as the most promising technology and was widely investigated in wastewater treatment. Here, a contact glow discharge electrolysis reactor was modified according to the basic principle and a new reactor was re-designed.Using the proposed set-up to treat wastewarter, the operating voltage can be increased and the efficacy of plasma is also improved obviously . Meanwhile, the lifetime of platinum wire electrode used was prolonged. The result was that the better efficient degradation was obtained. The new designed setups and the application technoque have been submitted to Chinese Patent Bureau. The names are listed below:1. The device of degradation of the organic pollutants in aqueous solution induced byplasma. Chinese Patent, application number: 03134546.82. The device of purification of drinking water by plasma. Chinese Patent, application number: 200420086147.93. A polymerization of acrylamide with acrylic acid by plasma. Chinese Patent, application number: 200410073481.5Part III Tradition methods of Chemistry Oxidative DegradationIntroduced six tradition methods of chemistry oxidative Degradation. Part IV Oxidative degradation of nitrophenols in aqueous solution by plasma with submersed glow discharger electrolysis.The oxidative degradation of 4-nitrophenol, 2,4- dinitrophenol, 2,4,6-trinitrophenols in aqueous solution by plasma with submersed glow discharge has been investigated. The reaction intermediates were determined by high performance chromatography (HPLC). Various influencing factors such as the initial pH, the concentrate of nitrophenols and the catalytic action of Fe~2+ ion were examined.The results indicate that the degradation pathways involve two steps. One is that the hydroxyl radicals attack the aromatic ring and open it; the other is the oxidation of the aliphatic compounds. The results also suggested that the reaction was obeyed a pseudo-first order kinetic reaction. It is enough to prove that the proposed method is an efficient way for the litrophenols degradation.Part V Oxidative degradation of chlorophenols in aqueous solution by plasma with submersed glow discharger electrolysis.The oxidative degradation of chlorophenols (CPs) in aqueous solution induced by plasma with submersed glow discharge has been investigated.The results indicate that CPs was eventually degradated into inorganic ion, dioxide carbon and water, the attack of hydroxyl radicals on the benzene rings of CP in initial stage of oxidative reactions was presumed to be key steps. They also suggest that the reaction was obeyed a pseudo-first order kinetic reaction and the proposed method is an efficient way forthe CPs degradation.Part VI The treatment of Brill...