过硫酸盐高级氧化法降解水中草除灵的实验研究

发布时间：2018-01-02 18:14

本文关键词：过硫酸盐高级氧化法降解水中草除灵的实验研究　出处：《江西理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：饮用水源中频繁检测出的除草剂等农药污染物等已经引起人们的广泛关注,且已经威胁到人们的身体健康。过硫酸盐高级氧化技术作为一种新型的水处理技术,是当前的水处理技术中的研究热点。本论文选取除草剂之一的草除灵为去除对象,研究用过硫酸盐高级氧化法降解草除灵。主要研究了基于紫外激活的高级氧化系统和基于热激活的高级氧化系统,从影响因素、动力学模型等角度对比考察了系统对草除灵的降解性能及其机理,为过硫酸盐高级氧化法在实际水处理中的应用提供理论基础。在紫外激活PS和PMS系统和热激活PS系统中均选取了草除灵初始浓度、氧化剂投加量、pH值、腐殖酸浓度作为影响因子进行了研究,并在UV/PS系统和热激活PS系统中研究了水中常见阴离子的影响。研究表明,UV/PS、UV/PMS和热激活PS工艺均能够有效的降解草除灵,并且在UV/PS、UV/PMS和热激活PS的各个工况条件下,草除灵的降解反应总是复合一级反应动力学。所有系统中随着草除灵初始浓度的降低,草除灵的降解率都不断提高,且一级动力学常数kobs值和草除灵初始浓度之间呈指数关系。在所有系统中增加氧化剂的浓度能使草除灵的降解率得到提高,且氧化剂浓度和草除灵的一级降解速率常数kobs值和呈现线性关系。UV/PS系统中,溶液pH为酸性或碱性都对草除灵的降解速率有一定程度提升,在中性条件下的草除灵降解效率最差。在UV/PMS系统中,pH对草除灵的降解速率影响不明显,整体来看在酸性条件的降解率好于中性和碱性条件。对热激活PS系统,中性条件下草除灵的降解速率最慢,而在碱性和酸性条件下降解速率都有上升,而且在碱性条件下的降解效果比酸性条件下要好。在所有系统中高浓度的腐殖酸的存在都会和草除灵的降解产生竞争关系,但是在热激活PS系统中发现低浓度的腐殖酸能促进草除灵的降解。通过向系统中投加TBA和EtOH,发现在UV/PS体系中主要起作用的是OH·,在UV/PMS体系中OH·和SO_4~-·同时起作用。在热激活系统中,酸性条件下系统中存在的自由基主要为SO_4~-·,在碱性条件下系统中存在的自由基主要为OH·。在UV/PS系统和热激活PS系统中,投加不同浓度的Cl~-,NO_3~-,HCO_3~-后均符合一级动力学模型,且投加Cl~-,NO_3~-,HCO_3~-均会在不同程度上抑制草除灵的降解,对草除灵的抑制程度大小符合HCO_3~-Cl~-NO_3~-的规律。
[Abstract]:Pesticide pollutants, such as herbicides, which are frequently detected in drinking water sources, have attracted extensive attention and have threatened people's health. Advanced oxidation technology of persulfate is a new water treatment technology. It is a hot research topic in the current water treatment technology. In this paper, one of the herbicides, Herbicide, is selected as the removal object. In this paper, the advanced oxidation system based on ultraviolet activation and the advanced oxidation system based on thermal activation were studied. The degradation performance and mechanism of the system were investigated from the point of view of kinetic model. In order to provide the theoretical basis for the application of persulfate advanced oxidation method in practical water treatment, the initial concentration and the dosage of oxidant were selected in UV activated PS, PMS system and thermal activated PS system. The pH value and humic acid concentration were used as the influencing factors, and the influence of common anions in water was studied in UV/PS system and thermally activated PS system. Both UV/PMS and heat activated PS process can effectively degrade Herba Chlorophylline, and under the conditions of UV / PSV / PSV / PMS and thermal activated PS under various operating conditions. The degradation rate of Caoziling was increased with the decrease of initial concentration in all systems. There was an exponential relationship between the kobs value of first-order kinetic constant and the initial concentration of Caoziling, and the degradation rate was increased by increasing the concentration of oxidant in all systems. The concentration of oxidant and the kobs value of the first-order degradation rate constant of Caoziling were linearly related. In the system of UV / PS, the pH value of the solution was acidic or alkaline, and the degradation rate of Caozidine was improved to a certain extent. In UV/PMS system, the effect of pH on the degradation rate was not obvious. On the whole, the degradation rate in acidic condition was better than that in neutral and alkaline condition. For thermally activated PS system, the degradation rate of Zaoziling was the slowest in neutral condition, but increased in alkaline and acidic conditions. And the degradation effect in alkaline condition is better than that in acid condition. In all systems, the existence of high concentration of humic acid will be competitive with the degradation of Herba Chlorophylline. However, it was found that the low concentration of humic acid could promote the degradation of Chlorophylline in the thermal activated PS system. By adding TBA and EtOH into the system, it was found that the main action in the UV/PS system was OH 路. In the UV/PMS system, OH 路and SO4- 路work simultaneously. In the thermal activation system, the main free radicals in the acidic system are so _ 4C _ (- 路). In the alkaline system, the main free radicals are OH 路. In the UV/PS system and the thermally activated PS system, different concentrations of Cl-No _ 3- are added to the system. All HCOs were in accordance with the first-order kinetic model, and the addition of Cl-No3C / HCO3- could inhibit the degradation of Chlorophyllum to varying degrees. The degree of inhibition to Caiziling was in accordance with the law of HCO3C- Cl-NO3-.
【学位授予单位】：江西理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X592;X703

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