饮用水消毒副产物稳定性机理的研究

发布时间：2018-06-28 22:20

本文选题：消毒副产物 + 三氯乙酸　；参考：《山西大学》2015年硕士论文

【摘要】：目前我国的生活饮用水净化处理过程大多采用氯化消毒方式,然而氯消毒剂在净化水质的同时很容易与水体中的一些有机物作用产生消毒副产物,卤乙酸就是其中一类较为常见的有机污染物,具有很强的“三致”效应,对环境和人体健康有很大危害,而三氯乙酸在氯消毒过程产生的卤乙酸中所占的比例最大,因此,本论文主要是以三氯乙酸为目标污染物,针对饮用水中卤乙酸的稳定性和降解规律的研究。本研究主要是通过测定饮用水中三氯乙酸在一系列影响因子(温度、pH、金属离子和活性炭)作用下的去除效果来确定三氯乙酸去除的最佳条件进而初步探讨以三氯乙酸为代表的卤乙酸转化和控制等方面的机理,为采取相应方法、工艺和设备控制消毒副产物的危害提供了依据,主要研究内容和结果如下：(1)热处理对水中的三氯乙酸(TCAA)有较好的去除效果。随着温度的升高和热处理时间的增加三氯乙酸的去除率均提高,该实验组设定条件下,三氯乙酸的去除率在煮沸60min时达到最大,为80.6%；水样处于室温状态0-30min时,空白组三氯乙酸自身的降解速率最高；热处理后的水样可检测出低浓度二氯乙酸(DCAA)其浓度随着温度的升高和持续时间的增加呈现上升趋势。(2)随着pH值的升高,三氯乙酸的浓度并没有明显变化。(3)与空白组相比,热处理条件下,引入钙离子后三氯乙酸的去除效果明显增强。加入钙离子的实验组,三氯乙酸的浓度随温度的升高和煮沸时间的增加呈下降趋势,水样刚达到沸点时,三氯乙酸的去除率为82.7%,随着煮沸时间增加到60min,三氯乙酸的去除率可达89.6%,明显高于空白组。(4)煮沸条件下,铁离子对三氯乙酸去除率的影响很大,引入铁离子的实验组水样中三氯乙酸的浓度明显下降,随着煮沸时间和加入的铁离子浓度的增加,三氯乙酸的去除率均不断提高；煮沸相同的时间,加入铁离子的实验组三氯乙酸的去除率和降解速率均略微高于加入钙离子的实验组。(5)颗粒活性炭对三氯乙酸的去除影响研究表明,活性炭对三氯乙酸有很好的去除效果。加入1g/L的活性炭作用1h后,三氯乙酸的去除率为78.6%,随着活性炭作用时间增加到4h,三氯乙酸的去除率可以提高到96.3%。此外,针对活性炭去除三氯乙酸的机理进行了初步探讨,研究发现,活性炭与三氯乙酸作用的过程中,随着活性炭作用时间的增加,水样中氯离子浓度明显上升,因此可以判断活性炭对三氯乙酸不仅具有吸附作用还有降解的作用。
[Abstract]:At present, the purification process of drinking water in our country mostly adopts chlorination disinfection method. However, chlorine disinfectant can easily produce disinfection by-products while purifying water quality and interacting with some organic compounds in water body. Haloacetic acid is one of the most common organic pollutants, which has a strong "three cause" effect, which is harmful to the environment and human health. However, trichloroacetic acid accounts for the largest proportion of halogenated acetic acid in the process of chlorine disinfection. In this paper, trichloroacetic acid is used as the target pollutant to study the stability and degradation of haloacetic acid in drinking water. The purpose of this study was to determine the optimal removal conditions of trichloroacetic acid by determining the removal effect of trichloroacetic acid in drinking water under a series of influencing factors (temperature pH, metal ion and activated carbon), and to discuss the application of trichloroacetic acid to the removal of trichloroacetic acid. The mechanism of conversion and control of haloacetic acid represented by acetic acid, The main contents and results are as follows: (1) Heat treatment has better removal effect of trichloroacetic acid (TCAA) in water. With the increase of temperature and heat treatment time, the removal rate of trichloroacetic acid increased. The removal rate of trichloroacetic acid reached the maximum of 80.6 at boiling 60min under the set conditions of the experimental group, while the water sample was in 0-30min at room temperature. In the blank group, the degradation rate of trichloroacetic acid was the highest, and the concentration of DCAA increased with the increase of temperature and duration. (2) with the increase of pH value, the concentration of dichloroacetic acid (DCAA) increased with the increase of pH value, and the concentration of dichloroacetic acid (DCAA) increased with the increase of temperature and duration. The concentration of trichloroacetic acid did not change obviously. (3) compared with the blank group, the removal efficiency of trichloroacetic acid was obviously enhanced after the introduction of calcium ion under heat treatment. The concentration of trichloroacetic acid decreased with the increase of temperature and boiling time, and when the water sample reached boiling point, the concentration of trichloroacetic acid decreased with the addition of calcium ion. The removal rate of trichloroacetic acid was 82.7%. With the boiling time increasing to 60 min, the removal rate of trichloroacetic acid reached 89.6, which was significantly higher than that of the blank group. (4) under boiling condition, iron ions had a great effect on the removal rate of trichloroacetic acid. The concentration of trichloroacetic acid in the water sample of the experimental group with the introduction of iron ions decreased obviously, and the removal rate of trichloroacetic acid increased with the increase of boiling time and the concentration of iron ion added. The removal rate and degradation rate of trichloroacetic acid in the experimental group with iron ions were slightly higher than those in the experimental group with calcium ion. (5) the effect of granular activated carbon on the removal of trichloroacetic acid showed that activated carbon had a good effect on the removal of trichloroacetic acid. The removal rate of trichloroacetic acid was 78.6 after adding 1 g / L of activated carbon for 1 h, and the removal rate of trichloroacetic acid could be increased to 96.3 with the increase of activated carbon time to 4 h. In addition, the mechanism of removal of trichloroacetic acid by activated carbon was preliminarily discussed. It was found that the concentration of chlorine ion in water increased with the increase of activated carbon time during the reaction of activated carbon with trichloroacetic acid. Therefore, it can be judged that activated carbon not only adsorbs but also degrades trichloroacetic acid.
【学位授予单位】：山西大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：R123.6

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