【作者】 张红梅；

【导师】 金星龙；

【作者基本信息】 天津理工大学 ， 环境科学， 2012， 硕士

【摘要】 辉光放电等离子体是一种新型的高级氧化技术,具有装置简单、放电电压低、处理效果好和能量效率高的特点。在辉光放电过程中能产生各种活性物质如OH、H、H2O2,其中OH、H2O2具有强氧化性,可以有效降解水溶液中的有机污染物,特别适用于有机废水的处理。本论文主要考察接触式、液下式和隔膜式三种辉光放电反应器产生等离子体过程中的Ⅰ-Ⅴ特征曲线、活性物质H2O2的浓度和以酸性橙(AO)为目标污染物时的脱色效果。本论文系统考察多电极接触辉光放电反应器的优势,利用接触辉光放电电解装置考察多电极对Ⅰ-Ⅴ曲线、H202浓度以及AO脱色效果的影响。结果表明：在2.0g/L的Na2SO4溶液中单电极与多电极对应的临界电压(VD)基本相同,均在490V左右；阳极液中的H2O2浓度和AO脱色率都随着反应时间和阳极数目的增加而升高,且随着阳极数目的增多,相应地能量效率也越来越高；利用不锈钢丝替代铂丝,改进原有的多电极接触辉光放电反应器,AO的脱色率明显加快,为以不锈钢丝为阳极的能量效率均比以铂丝为阳极时高；对于较高浓度的AO溶液,多电极接触辉光放电实验装置也有较好的处理效果。利用液下辉光放电实验装置考察溶液初始电导率和电解质的影响,优化阳极位置、阴极材质和尺寸等实验条件,以及研究多电极对Ⅰ-Ⅴ曲线、H2O2浓度和AO脱色效果的影响。结果表明：临界电压VD随溶液电导率增高而降低,放电处理20min后溶液中H202浓度随溶液电导率升高而增大；当溶液初始电导率相同时,VD受电解质组分的影响较小；阳极水平插入时H2O2的浓度最大,AO的脱色率最高；阴极材质和尺寸对临界电压的影响不大；发现单电极与多电极对应的临界电压基本相同,均在500V左右；阳极液中的H2O2浓度和AO脱色率都随着反应时间和阳极数目的增加而升高,而且随着阳极数目的增多,相应的能量效率也越来越高；对于较高浓度的AO溶液,多电极液下辉光放电实验装置也有较高的脱色效率；随着阳极数目的增加,COD和TOC的去除率都明显增大。利用隔膜辉光放电实验装置优化孔径、电压等实验参数,考察溶液初始电导率对Ⅰ-Ⅴ曲线的影响,及电解质对H2O2浓度和AO脱色效果的影响。结果表明：H2O2浓度和AO脱色率均随着孔径的增大而升高；当溶液初始电导率相同时,相同电解质组分中H2O2的浓度越高相应溶液中AO的脱色率也就越高,电解质组分对H2O2的浓度和AO的脱色率有一定影响,在NaCl溶液中,辉光放电反应过程中H2O2的浓度较低,但AO的脱色率最高。更多还原

【Abstract】 Glow discharge plasma (GDP) is a novel advanced oxidation technology, since many species such as OH, H, H2O2are produced in the discharge process. These radicals can diffuse in the surrounding liquid and be used for the removal of dissolved compounds. Especially, OH, with higher oxidation potential, can break the molecular bonds of organic pollutants. This makes GDP particularly suitable for decontamination. In addition, GDP has many advantages, such as simpler equipment, lower applied voltage and higher energy efficiency. In order to study the onset and active species of GDP, this paper investigated Ⅰ-Ⅴ characteristic curve, concentration of H2O2and discoloration efficiency of Acid Orange (AO) with three kinds of glow discharge reactors.This paper systematically investigated the onset multi-anode contact glow discharge electrolysis (m-CGDE). It was found that the critical voltage of m-CGDE was same to that of single anode. The concentration of H2O2in the anolyte and discoloration rates of AO increased with the increase of treatment time and anode number. It was also demonstrated that improved m-CGDE reactor efficiently accelerated the discoloration process of AO by replacing platinum wire with stainless steel wire. For higher concentration AO solution, m-CGDE also showed higher discoloration efficiency.In addition, this paper investigated the onset of underwater glow discharge. The experimental conditions such as the position of the anode, cathode material and size, voltage were optimized. The results showed that VD decreased with the increasing conductivity of solution. Different electrolytes had insignificant effect on VD. It was found that the critical voltage of multi-anode glow discharge electrolysis (m-GDE) was same to that of single anode. The concentration of H2O2in the anolyte and discoloration rates of AO increased with the increase of treatment time and anode number. For higher concentration AO solution, m-GDE also showed higher discoloration efficiency. COD and TOC removal rate increased with an increase of anode number.Finally, this paper investigated the onset and active activity of diaphragm glow discharge (DGD). It was found that Ⅰ-Ⅴ characteristic was similar to that of CGDE. IThe concentration of H2O2in the anolyte and discoloration rates of AO increased with the increase of hole’s diameter. The discoloration rates of AO increased with the increase of the concentration of H2O2in the same electrolyte. Different electrolytes had effect on the concentration of H2O2in the anolyte and discoloration rates of AO, especially the NaCl solution.更多还原