【作者】 杨彬；

【导师】 雷乐成；

【作者基本信息】 浙江大学 ， 环境工程， 2004， 硕士

【摘要】 高压脉冲放电技术应用于水处理领域的研究刚刚兴起，本文利用该技术对染料废水进行了较为系统的基础研究。第一部分研究了高压脉沖在水中的放电类型，及其对染料废水降解率的影响及作用机理。第二部分提出了一种新型的放电体系——气、液两相同时放电，初步探讨了该体系对染料废水的降解机理。 第一部分，首先从实验现象上定义了高压脉冲液相放电的三种基本放电类型：电晕放电、混合放电、火花放电等，系统地研究了影响放电类型的条件因素。当输入电压越大、通入气体气量越大、电极间距越小、溶液电导率越低，放电类型越有利于火花放电转化。实验以阳离子红X-GRL为模拟污染物进行了影响因素的正交优化，确定了输入电压和溶液电导率是影响其降解率的两个主导因素。从放电类型角度来看，火花放电更有利于有机物染料的降解，混合放电次之，电晕放电较差。火花放电时，添加一定量双氧水可大幅度提高阳离子红的降解速率和最终降解率。TiO₂的加入并没有明显提高其降解率。实验还考察了溶液电导率对酸性品红降解率的影响。随着水中电导率的上升，放电形式逐渐从火花放电转向电晕放电。火花放电具有较高的能量利用率，其中OH自由基表观产率和光子产率分别为11.57 μmol/L和0.0978 photon/s。高压脉冲液相放电降解染料废水的过程中，OH自由基氧化作用并不占主导因素，随着放电类型从火花放电转向电晕放电，这种作用表现得更加不明显。 第二部分较系统地考察气、液两相同时放电体系降解酸性橙染料废水。研究表明通氧气时，该体系降解酸性橙染料废水具有明显的协同作用，而且对偶氮染料具有普遍的去除性。实验还考察了输入电压、放电电极间距、放电频率等主要操作条件对酸性橙降解率和能量利用率的影响。通过比较不同载气时单独气相、单独液相、气液两相同时放电水中臭氧和双氧水的产率以及酸性橙的降解情况，可认为气相放电产生的臭氧在酸性橙的降解过程中起到了关键性的作用。更多还原

【Abstract】 Over the recent years there has been a growing interest in the development of pulsed high-voltage discharge method for degrading toxic organic contaminants in water. The objective of the present work is to perform a fundamental investigation on degrading organic dyes in water using this method. It was composed of two parts: part one, three kinds of discharge types were produced and effects of them on degradation efficiency were investigated; part two, a novel technique combined with liquid and gas phase discharges for dyes degradation in aqueous solution was developed.Part one, corona, mixed and spark discharges in water were defined by the pulsed high-voltage discharge phenomenon. The discharge types induced by the various operation conditions have been examined. Spark discharge was easily occurred with applied voltage increasing, gas flux increasing, electrode distance decreasing and liquid conductivity decreasing. The conditions such as applied voltage and liquid conductivity have important roles on degradation efficiency of cationic red X-GRL. Higher degradation efficiency of organic dyes has been achieved by spark discharge. The degradation efficiency was greatly enhanced with a dosage of H2O2 addition and was not enhanced with TiO2. The apparent production of OH radicals and quantum yields generated by spark discharge in distilled water were 11.57 umol/L and 0.0978 photon/s, respectively. The processes of degradation showed that the oxidative effects through OH radical oxidation did not play an important role and did weaken with the discharge type changing to corona discharge.Part two, the technique of combined with liquid and gas phase discharges (LGD) using pulsed high voltage was developed. In this system, the apparent synergistic effects for acid orange II (AO) degradation in the presence of oxygen were observed. The enhancement of degradation rate for AO was around 302%. Furthermore, higher energy efficiency can be obtained in comparison with individual liquid phase discharge (LD) or gas phase discharge process (GD). Important operating conditions such as electrode distance, applied voltage, pulse repetition rate, and types of dyeswere also investigated. The AO degradation in the presence of oxygen by LGD may proceed through the direct ozone oxidation and the decomposition of the ozone induced by the liquid phase discharges.更多还原