饮用水消毒副产物三氯乙醛去除性质的研究

发布时间：2018-05-03 12:30

本文选题：消毒副产物 + 三氯乙醛　；参考：《哈尔滨工业大学》2014年硕士论文

【摘要】：我国现行的新《生活饮用水卫生标准》(GB5749-2006)中,水质检测项目增添至106项,其中消毒指标被列为常规项目。给水处理末端消毒工艺在灭活水体中的种种致病微生物的同时,也会生成一系列卤代化合物,即消毒副产物。除去三卤甲烷和卤乙酸外,卤乙醛是消毒副产物的又一大组成部分,其中又以三氯乙醛(在水中以水合氯醛的形式存在)为主。考虑到消毒副产物三氯乙醛在水厂出水中的广泛存在,本课题将三氯乙醛作为研究对象,考察了管网条件下其水解、氧化和还原的降解性质,以及非管网条件下三氯乙醛紫外光解、挥发性、超声降解、微波降解、活性炭吸附和反渗透去除的性质。藉此本文完善了三氯乙醛降解去除性质方面的研究,为提高饮用水的安全性提供了一定的科学依据。管网条件下实验结果显示:三氯乙醛的水解反应明显受溶液p H和温度的影响,随p H和温度的提高而加快;三氯乙醛可以被高浓度的余氯氧化,而不能被氯胺氧化;三氯乙醛可以通过脱氯反应被铁粉还原,且在溶液p H为4.0~6.0的范围内有最佳的还原效果。但在实际的管网条件下,受限于p H、温度、余氯量等因素,三氯乙醛的水解、氧化和还原降解效果并不佳。非管网条件下的实验结果显示:三氯乙醛的紫外光解反应明显受溶液p H和紫外灯功率的影响,随溶液p H和紫外灯功率的提高而加快;且在相近的实验条件下,三氯乙醛紫外光解的反应速率明显大于三氯乙醛水解反应的速率。与三氯乙醛水解反应的主要产物(为三氯甲烷)相比,其紫外光解反应的主要产物则是氯离子,降解地更彻底。在干扰物对三氯乙醛紫外光解反应的影响中,I-和NO3-起到促进作用,在同等浓度下,I-的促进效果明显优于NO3-;腐殖酸则起抑制作用;Cl-没有明显地影响。这说明存在紫外吸收峰的物质会影响三氯乙醛的紫外光解反应速率,或促进或抑制。紫外降解法对溶液中的三氯乙醛有较可观的去除效果,且无二次污染。此外,在非管网条件下,对于去除溶液中三氯乙醛,加热/微波煮沸和反渗透法具有快捷、高效的特点,前者能高效去除自来水中的三氯乙醛,而后者能不受p H和初始浓度的影响;吸附法有一定的去除效果,但受吸附剂和流速的影响显著;搅拌法和超声法则基本无效。
[Abstract]:In the current "Sanitary Standard for domestic drinking Water" GB5749-2006, 106 items of water quality testing were added, among which disinfection indexes were listed as routine items. While inactivating various pathogenic microorganisms in water, a series of halogenated compounds, that is, disinfection by-products, are produced by the end disinfection process of water treatment. Apart from trihalomethane and haloacetic acid, halogen acetaldehyde is another major component of disinfection by-products, in which trichloroacetaldehyde (in the form of chloral hydrate in water) is the main component. Considering the widespread presence of disinfection by-product trichloroacetaldehyde in the effluent of a water plant, the degradation properties of chloral in hydrolysis, oxidation and reduction under the condition of pipe network were investigated. The properties of UV photolysis, volatility, ultrasonic degradation, microwave degradation, activated carbon adsorption and reverse osmosis removal of trichloroacetaldehyde under non-pipeline conditions were also discussed. In this paper, the study on the degradation and removal of trichloroacetaldehyde has been improved, which provides a scientific basis for improving the safety of drinking water. The experimental results show that the hydrolysis of trichloroacetaldehyde is obviously influenced by pH and temperature of solution, and accelerated with the increase of pH and temperature, and that trichloroacetaldehyde can be oxidized by high concentration of residual chlorine, but not by chloramine. Trichloroacetaldehyde can be reduced by iron powder through dechlorination, and the best reduction effect is obtained in the range of pH 4.0 ~ 6.0. However, under the actual pipe network conditions, the hydrolysis, oxidation and reduction of trichloroacetaldehyde are not good due to the factors such as pH, temperature, residual chlorine content and so on. The experimental results show that the UV photolysis reaction of trichloroacetaldehyde is obviously affected by the power of solution pH and UV lamp, which is accelerated with the increase of power of solution pH and UV lamp, and under the similar experimental conditions, the UV photodissociation reaction of trichloroacetaldehyde is obviously affected by the power of solution pH and UV lamp. The UV photolysis rate of trichloroacetaldehyde is obviously higher than that of trichloroacetaldehyde hydrolysis. Compared with the main product of the hydrolysis of trichloroacetaldehyde (trichloromethane), the main product of the UV photolysis reaction is chloride ion, which is degraded more thoroughly. I- and NO3- promoted the ultraviolet photolysis reaction of trichloroacetaldehyde, and the effect of I- was better than that of No3 at the same concentration, but humic acid had no obvious effect on it. It is suggested that the UV absorption peak may affect the UV photolysis rate of trichloroacetaldehyde, or promote or inhibit the UV photodissociation of trichloroacetaldehyde. The UV degradation method has a considerable removal effect of trichloroacetaldehyde in the solution and has no secondary pollution. In addition, the heating / microwave boiling and reverse osmosis methods are fast and efficient for the removal of trichloroacetaldehyde from the solution under non-pipe network conditions. The former can effectively remove trichloroacetaldehyde from tap water. The latter can not be affected by pH and initial concentration; adsorption method has a certain removal effect, but is significantly affected by adsorbent and flow rate; stirring method and ultrasonic rule are basically ineffective.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU991.2

【相似文献】