饮用水源中不同粒径颗粒物吸附抗生素特征研究

发布时间：2019-02-12 19:46

【摘要】：各种各样的颗粒物存在于天然水体中,即使饮用水源水中也含有大量小颗粒,尤其是粒径小于1μm的颗粒。这些颗粒粒径较小,但其比表面积却很大,它们往往与污染物相互作用并成为其载体,在饮用水传统处理工艺中亦不能被很好去除,进而随水厂出水进入人体,严重威胁人体健康。为验证小颗粒强大的吸附能力,在分析饮用水厂处理工艺对颗粒物的去除特征后,以1μm为分界点对饮用水源中颗粒进行分级,将其分为粒径大于1μm的大颗粒和0.05-1μm小颗粒。以此为基础进行颗粒物吸附饮用水源中抗生素的特征研究。世界多个地区抗生素滥用现象比较严重,各地水体环境中均检测到了抗生素残留,其进入到水体后会被水体中的颗粒物吸附,进而可能会随着颗粒物进入到饮用水中,严重影响饮用水的水质安全和人类健康。通过查阅文献,选取了四大类抗生素中的四种作为研究对象。通过优化前处理过程和仪器的测定条件,建立了四种抗生素的微波萃取前处理方法及液相色谱与质谱联用技术测定方法。四种抗生素经过不停的吸附解吸过程,均能在360min达到动态平衡,平衡时抗生素有32%-44%分布在颗粒上;除青霉素外,粒径0.05-1μm小颗粒的吸附量又占颗粒总吸附量的56%-70%。天然水体中小颗粒物含量较低,但其吸附能力却很强,残留在水体的抗生素有相当一部分被吸附在颗粒物上。这些颗粒在饮用水处理中难以有效去除,这也使饮用水安全存在着一定的安全隐患。pH对四种抗生素吸附量影响不尽相同。d1μm的大颗粒吸附量随pH变化波动很大,峰值出现在酸性或碱性条件下;0.05-1μm粒径颗粒的吸附量随p H有规律的变化,峰值出现在中性条件下。但是固相吸附量最大值均出现在pH=7处,绝大多数情况下0.05-1μm粒径颗粒的吸附量大于粒径d1μm颗粒。吸附平衡时小颗粒、大颗粒上的吸附位点均未达到饱和。当投加两种相同浓度抗生素时,二者的吸附总量均有不同程度的增加。一般情况下,吸附量的增加程度小于抗生素总量的增加程度。四种抗生素的竞争吸附结果显示,罗红霉素、青霉素G的竞争能力最强,甲氧苄啶次之,萘啶酸的竞争能力最弱。研究结果为饮用水处理中抗生素优先控制种类提供了参考,同时对于饮用水处理工艺的改善及水质提高都有重要意义。
[Abstract]:All kinds of particles exist in natural water bodies. Even drinking source water contains a large number of small particles, especially those smaller than 1 渭 m in size. The size of these particles is small, but their specific surface area is very large. They often interact with pollutants and become their carriers. They can not be well removed in the traditional treatment process of drinking water, and then enter the human body with the effluent from the water plant. It is a serious threat to human health. In order to verify the strong adsorption capacity of small particles, after analyzing the removal characteristics of particulate matter in drinking water treatment process, the particles in drinking water source were classified with 1 渭 m as the boundary point. It can be divided into two groups: large particle size > 1 渭 m and small particle size 0.05-1 渭 m. On the basis of this, the characteristics of the adsorption of antibiotics in drinking water source by particulate matter were studied. Antibiotic abuse is serious in many parts of the world. Antibiotic residues are detected in various water environments, which will be adsorbed by particulate matter after entering the water, and then may be absorbed into drinking water with particulate matter. The safety of drinking water quality and human health are seriously affected. Four of the four kinds of antibiotics were selected as the object of study through literature review. By optimizing the pretreatment process and the determination conditions of the instrument, a microwave extraction pretreatment method for four antibiotics and a method for the determination of four antibiotics by liquid chromatography-mass spectrometry were established. After continuous adsorption and desorption, the four antibiotics could reach dynamic equilibrium in 360min, and 32% -44% of the antibiotics were distributed on the particles in equilibrium. In addition to penicillin, the adsorption capacity of 0.05-1 渭 m small particles accounted for 56- 70% of the total adsorption capacity of the particles. The content of small particles in natural water is relatively low, but its adsorption capacity is very strong, and a considerable part of the antibiotics remaining in the water body are adsorbed on the particles. It is difficult to remove these particles effectively in drinking water treatment, which makes the drinking water safe to some extent. The effects of pH on the adsorption of four antibiotics are different. The adsorption capacity of large particles at d 1 渭 m fluctuates with the change of pH. The peak appeared in acidic or alkaline condition. The adsorption capacity of 0.05-1 渭 m particle changed regularly with pH, and the peak appeared in neutral condition. In most cases, the adsorption capacity of 0.05-1 渭 m particles is larger than that of d1 渭 m particles. When the adsorption equilibrium is small, the adsorption sites on the large particles are not saturated. When two antibiotics of the same concentration were added, the total amount of adsorption increased in varying degrees. In general, the increase in adsorption capacity is less than the increase in the total amount of antibiotics. The results of competitive adsorption of four antibiotics showed that roxithromycin and penicillin G had the strongest competitive power, trimethoprim followed by trimethoprim, and naphthalic acid was the weakest. The results provide a reference for the priority control of antibiotics in drinking water treatment, and are of great significance to the improvement of drinking water treatment process and the improvement of water quality.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU991.2

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