磁场强化电动修复三氯生污染土壤的研究

发布时间：2018-05-31 19:47

本文选题：三氯生 + 土壤污染　；参考：《江苏大学》2017年硕士论文

【摘要】：目前土壤污染日益突出,成为一个严重的问题,因而土壤修复也就成为了环境领域中具有发展前景的研究领域。个人护理产品和药物逐渐成为一种新兴的土壤污染物,而这些污染物由于其在最初的使用领域具有低浓度,急性毒害小的特点不被关注。本文的研究对象为三氯生,其作为一种广谱抗菌剂,大量使用于系列个人和家庭产品中,如香皂、纺织物、玩具和涂料中。现在,三氯生已经被认定为土壤环境中广泛存在的十大有机污染物之一。尽管三氯生的极性毒性并不高,但是其在环境中难以降解,易干扰人体内分泌,影响细胞基因的表达,是一种新型环境污染物。目前土壤修复技术不断发展,传统的土壤修复技术大致可划分为三类,即物理修复、化学修复以及生物修复。随着科技发展和研究的不断深入,一些复合修复技术也逐渐兴起。复合修复技术是指由两种或者两种以上的修复方法共同作用的治理污染土壤的修复技术。本研究设计开发了基于磁场强化的电动复合修复技术,用于三氯生污染土壤的修复研究,其作为一种高效、低成本、无污染的修复技术具有良好的发展前景。本试验构建了新型的磁场强化的电动修复土壤的修复系统,并深入研究其对三氯生污染土壤的修复效果,取得了主要研究成果如下:⑴首先,建立了土壤中三氯生的回收和检测方法,同时开展了三氯生的吸附动力学研究。试验结果表明1.0g土壤用50mL的甲醇两次超声萃取后,三氯生回收率在92.17%~96.45%之间,281nm检测波长,取得良好出峰效果;土壤对三氯生的吸附在1000分钟内即可完成;三氯生的解吸试验结果表明三氯生在土壤中的吸附过程是不可逆的。⑵其次,研究了含水率和电极形状对磁强化电动修复的影响,确定试验过程中土壤含水率为35.0%,采用石墨片状电极。正交优化试验结果表明,电势梯度和磁场强度增大对修复效果提高都有促进作用,污染物浓度越低,这种促进作用越明显。当试验中电压梯度为3v/cm,磁场强度设置为80mT,污染物浓度为1000mg/kg时,污染物三氯生取得最大去除率50.7%。⑶最后,分析了磁强化电动修复试验对土壤的pH、含水率、电导率以及温度等理化性质的影响。试验中每隔10小时记录一次土壤的温度,试验结束后测量了土壤的pH、含水率、电导率。土壤pH在阳极区降低,阴极区升高,这是由于水电解反应在电极区产生了大量的氢氧根和氢离子,pH分布结果表明磁场促进了酸碱中和面向阴极迁移;土壤室的土壤含水率分布均匀,与初始状态比呈稳定状态,温度变化波动范围也较小;电极槽内土壤含水率和土壤温度呈周期性波动,这是由于电极槽内电解液采用周期性投加;土壤区含水率从阳极向阴极区逐渐升高;土壤区的电导率呈两端高中间低的现象,即电导率在阳极区和阴极区较高,中间区最低。
[Abstract]:Soil pollution has become a serious problem, so soil remediation has become a promising research field in the field of environment. Personal care products and drugs have gradually become a new soil pollutant, which is not concerned because of its low concentration in the field of initial use. As a broad-spectrum antimicrobial agent, triclosan is widely used in a series of personal and domestic products, such as soap, textiles, toys and paints. Now, triclosan has been identified as one of the ten most widespread organic pollutants in the soil environment. Although the polar toxicity of triclosan is not high, it is difficult to degrade in the environment, easy to interfere with human endocrine and affect the expression of cell genes, so it is a new environmental pollutant. At present, soil remediation technology is developing continuously. The traditional soil remediation technology can be divided into three categories: physical remediation, chemical remediation and bioremediation. With the development of science and technology and the development of research, some composite repair technology is also rising. Composite remediation technology refers to the remediation of contaminated soil by two or more remediation methods. In this study, an electric composite remediation technology based on magnetic field was designed and developed, which can be used in the remediation of trichlorogenic contaminated soil. As a highly efficient, low-cost and pollution-free remediation technology, it has a good prospect. In this experiment, a new magnetic field enhanced electric remediation system for soil was constructed, and its remediation effect on trichlorogenic contaminated soil was studied in depth. The main research results are as follows: 1. A method for the recovery and detection of triclosan in soil was established, and the adsorption kinetics of triclosan was studied. The results showed that the recovery rate of triclosan was 92.17% ~ 96.45% after twice ultrasonic extraction with 50 mL methanol in 1.0 g soil, and the detection wavelength of 281nm was obtained, and the adsorption of triclosan on soil could be completed within 1000 minutes. The desorption test of triclosan showed that the adsorption process of triclosan in soil was irreversible. Secondly, the effects of water content and electrode shape on magnetically enhanced electrokinetic remediation were studied. The soil moisture content was determined to be 35.0 and graphite sheet electrode was used. The results of orthogonal optimization test show that the increase of potential gradient and magnetic field intensity can promote the improvement of remediation effect, and the lower the concentration of pollutants, the more obvious this effect is. When the voltage gradient was 3 v / cm, the magnetic field intensity was set to 80 Mt, and the pollutant concentration was 1000mg/kg, the maximum removal rate of trichloroethylene was 50.7.3. Finally, the pH and moisture content of the soil were analyzed. Effects of electrical conductivity and temperature on physical and chemical properties. The soil temperature was recorded every 10 hours. The pH, water content and conductivity of the soil were measured after the experiment. The pH of soil decreased in the anode region and increased in the cathode area, which was due to a large amount of hydroxide and hydrogen ion pH distribution in the electrode region produced by the water electrolysis reaction. The results showed that the magnetic field promoted the migration of acid and base and toward the cathode. The distribution of soil moisture content in soil chamber is uniform, and the ratio of soil moisture content to initial state is stable, and the range of temperature fluctuation is small, and the soil moisture content and soil temperature in electrode tank fluctuate periodically. This is due to the periodic addition of electrolyte in the electrode cell, the increase of soil moisture content from anode to cathode, and the phenomenon that the conductivity of soil area is high and low at both ends, that is, the conductivity is higher in the anode and cathode area, and the lowest in the middle zone.
【学位授予单位】：江苏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X53

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