次氯酸钠氧化降解水杨酸的反应研究

发布时间：2018-07-14 08:35

【摘要】：近年来药品和个人护理用品(PPCPs)类污染物向环境中的排放量越来越大,而传统污水处理的工艺对这类污染物的降解效果并不明显,导致了PPCPs类物质在水体环境的中的含量一直在增长,呈现出了一种假持续性现象,从而受到了人们的关注。水杨酸具有许多药理作用,可以消炎抗菌,可以作为防腐剂,在医药和化妆品等行业中被广泛的使用,目前于多种水环境中均已检测出水杨酸类的污染物。水杨酸对眼睛有刺激性,皮肤如果持续性的接触到高浓度水杨酸可能会被灼伤,短时间内反复接触水杨酸也可能引发皮炎。水杨酸也可以刺激人体呼吸系统,引发咳嗽或着肺部和胸部的不适;当人体摄入水杨酸时,会对肠胃与粘膜产生刺激;水杨酸可以和机体内的白蛋白质产生反应,引发水杨酸中毒,导致肾损害等。次氯酸钠是一种具有强氧化性的氧化剂,使用方便安全,易于储存,被广泛的用于有机物氧化和污水消毒。本文主要探讨次氯酸钠氧化水杨酸的降解反应,以及反应的影响因素和产物毒性。本文研究了以次氯酸钠作为氧化剂来氧化水杨酸的氧化降解效果,结果显示,次氯酸钠可以有效地氧化降解水杨酸。分别以水杨酸与次氯酸钠作为单一变量时,次氯酸钠氧化去除水杨酸的反应均显示为假一级反应,既其氧化过程可以近似的看作符合二级反应的动力学模型。增大次氯酸钠有效氯的浓度有利于加快反应的进行,然而增大水杨酸的浓度,表观反应速率常数会减小。p H对该反应有着非常大的影响,反应速率常数会随着p H值的减小而增大。反应体系的温度对于整个反应的过程有着较大的影响,其影响符合范特霍夫规则,次氯酸钠氧化降解水杨酸反应的表观活化能Ea=43.22 k J·mol-1,反应温度越高,氧化降解去除效果越好。通过测定反应过程的TOC发现,水杨酸被次氯酸钠氧化降解生成CO2、H2O以及一部分难以矿化的有机物。明亮发光杆菌的毒性测试,其结果表明,在整个反应的过程中,反应系统的毒性是在不断变化的,初始样品的抑制率高,毒性最强;,反应进行到最后,抑制率很低,毒性很小;中间过程中随着时间的推移毒性的强弱会产生波动。论文同时还研究了水中共存物质对次氯酸钠氧化水杨酸的影响。结果表明,亚硝酸根离子会同次氯酸钠发生反应,从而降低水杨酸的降解反应,水杨酸的降解速率随着NO2-浓度的增加而减慢。锌离子和硫酸根离子以及吐温-80对于该反应没有明显效果,基本上不影响反应的降解速率。铜离子和溴离子可以影响该反应,当溶液中含有一定浓度的铜离子和溴离子时,反应速率会加快,且反应速率常数随着Cu2+和Br-浓度的增加而增大。腐殖酸的存在会抑制次氯酸钠氧化水杨酸的反应,且抑制效果随着其浓度的增大而增加。十二烷基苯磺酸钠(SDBS)对于此反应会产生一定的影响:在低浓度范围内的SDBS可以促进次氯酸钠氧化水杨酸的反应,反应速率常数会随着SDBS的浓度的升高而变大,在SDBS浓度达到一定的大小后,其对反应的促进效果会减小甚至没有促进效果。
[Abstract]:In recent years, the emission of drugs and personal care products (PPCPs) pollutants to the environment is increasing, and the degradation effect of traditional sewage treatment technology is not obvious, which leads to the increase in the content of PPCPs in the water environment. Salicylic acid has many pharmacological effects. It can be used as antiseptic and antiseptic. It can be used as a preservative and is widely used in pharmaceutical and cosmetic industries. The salicylic acid has been detected in a variety of water environment. Salicylic acid is irritating to the eyes. If the skin is continuously exposed to high concentration of salicylic acid, it may be burned. Injury, repeated exposure to salicylic acid in a short time may also cause dermatitis. Salicylic acid also stimulates the body's respiratory system, triggers a cough or discomfort in the lungs and chest; when the body takes in salicylic acid, it stimulates the stomach and mucous membrane; salicylic acid can react with white egg white matter in the body and cause salicylic acid poisoning and cause kidney damage. Sodium hypochlorite is a kind of oxidizing agent with strong oxidation. It is easy to use, safe and easy to store. It is widely used in organic oxidation and sewage disinfection. This paper mainly discusses the degradation reaction of sodium hypochlorite oxidation salicylic acid, the influence factors of the reaction and the toxicity of the product. This paper studies the oxidation of water with sodium hypochlorite as an oxidizing agent. The results of oxidation degradation of salicylic acid show that sodium hypochlorite can effectively oxidize and degrade salicylic acid. When salicylic acid and sodium hypochlorite are used as a single variable, the reaction of sodium hypochlorite to salicylic acid by oxidizing sodium hypochlorite is a pseudo first order reaction, and the oxidation process can be considered approximately as a kinetic model conforming to the two stage reaction. The concentration of the effective chlorine of sodium hypochlorite is beneficial to the acceleration of the reaction. However, increasing the concentration of salicylic acid, the apparent reaction rate constant decreases the effect of.P H on the reaction, and the reaction rate constant will increase with the decrease of the P H value. In accordance with the van t Hof rule, the apparent activation energy of the reaction of salicylic acid by sodium hypochlorite is Ea=43.22 K J. Mol-1, the higher the reaction temperature, the better the effect of oxidation degradation. By the determination of the TOC of the reaction process, the salicylic acid is oxidized and degraded by sodium hypochlorite to produce CO2, H2O, and a part of the organic matter which is hard to mineralized. The toxicity test shows that the toxicity of the reaction system is constantly changing during the whole reaction process, the inhibition rate of the initial sample is high and the toxicity is the strongest. The inhibition rate is very low and the toxicity is very small at the end of the reaction. In the middle process, the toxicity of the reaction will fluctuate with time. The paper also studies the coexistence in the water. The effect of the quality on sodium hypochlorite oxidation of salicylic acid showed that the nitrite ion would react with sodium chlorate, thus reducing the degradation reaction of salicylic acid. The degradation rate of salicylic acid slowed with the increase of NO2- concentration. Zinc ions and sulfate ions and Twain -80 had no obvious effect on the reaction, and basically did not affect the reaction. The degradation rate. Copper ions and bromine ions can affect the reaction. When the solution contains a certain concentration of copper ions and bromine ions, the reaction rate increases, and the reaction rate constant increases with the increase of Cu2+ and Br- concentration. The addition of twelve alkyl benzene sulfonate (SDBS) has a certain effect on this reaction: the SDBS in the low concentration range can promote the reaction of sodium hypochlorite oxide salicylic acid. The reaction rate constant will increase with the increase of the concentration of SDBS, and the effect on the reaction will be reduced after the concentration of SDBS is reached to a certain size. It doesn't even promote the effect.
【学位授予单位】：河南师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X703

【参考文献】