饮用水中铊污染的净化技术研究

发布时间：2018-04-05 22:25

本文选题：饮用水　切入点：铊　出处：《广东工业大学》2013年硕士论文

【摘要】：铊具有强蓄积性毒性,可以通过呼吸、饮用水和食物等途径进入人体,造成人体的急性或慢性铊中毒,造成永久性损害。由于操作失误或管理不善等原因,我国一些城市还经常出现一些突发性的饮用水污染事件,这些突发性水污染事件常常会影响到饮用水的安全。因此对自来水厂水源水发生突发性它污染时,如何在水厂内部通过适当的处理技术,使铊污染得到有效去除并符合国家标准,保证人民群众的饮用水安全,是当前迫切需要研究解决的一个课题。本课题分别采用吸附法和氧化絮凝法去除饮用水中的铊。 (1)以羧甲基壳聚糖和膨润土为原料,制备羧甲基壳聚糖-膨润土复合吸附剂,并将其用于对水中铊的吸附,研究了吸附时间、溶液pH和温度等对铊吸附性能的影响。结果表明,羧甲基壳聚糖-膨润土复合吸附剂对废水中铊的吸附,随废水pH值升高而增大；当水温低于50℃时,升温对吸附有利,当水温高于50℃时,再进一步升温,会导致吸附剂对铊的平衡吸附量减小；吸附剂对铊的吸附容量与铊的浓度关系密切,当铊的初始浓度为100mg/L,吸附平衡时铊的浓度为48.54mg/L,对应的吸附容量为15.43mg/g。通过改变吸附剂的用量可以达到控制出水铊浓度的目的。 (2)氧化絮凝法基本上是对自来水厂现有工艺各操作单元进行重新组合形成的一种新工艺：氧化-混凝-沉淀-过滤-消毒。在水环境中,铊一般以一价和三价态的形式存在。其中,T1的一价化合物稳定性很高,不易沉淀,而T1的三价化合物不稳定,易沉淀。因此,在除铊前把一价氧化为三价是除铊的有效途径。从处理效果看,次氯酸钠-聚合硫酸铁/聚合氯化铝和漂白粉-聚合硫酸铁/聚合氯化铝四种组合工艺对铊的去除率达到90%以上。其中,50mL铊浓度为3.03mg/L的溶液中,加入0.6g漂白粉,pH=10,2mL聚合氯化铝的时,铊的浓度降到了0.05μg/L,达到国家规定的排放标准,去除率达到99.998%。
[Abstract]:Thallium has strong accumulative toxicity, which can enter human body through breathing, drinking water and food, causing acute or chronic thallium poisoning and permanent damage.As a result of misoperation or mismanagement, some unexpected incidents of drinking water pollution often occur in some cities of our country, which often affect the safety of drinking water.Therefore, how to remove thallium pollution effectively and accord with the national standard in the water plant through appropriate treatment technology, and ensure the safety of drinking water for the people, when the source water of the water works occurs sudden pollution, so as to ensure the safety of the drinking water of the people.It is an urgent problem that needs to be studied and solved at present.In this paper, the removal of thallium in drinking water by adsorption method and oxidative flocculation method respectively.1) Carboxymethyl chitosan and bentonite were used as raw materials to prepare carboxymethyl chitosan-bentonite composite adsorbent and used to adsorb thallium in water. The effects of adsorption time, solution pH and temperature on the adsorption properties of thallium were studied.The adsorption capacity of the adsorbent on thallium is closely related to the concentration of thallium. When the initial concentration of thallium is 100 mg / L, the concentration of thallium is 48.54 mg / L when the initial concentration of thallium is 100 mg / L, the corresponding adsorption capacity is 15.43 mg / g.The concentration of thallium in effluent can be controlled by changing the amount of adsorbent.(2) Oxidation flocculation is a new process, namely, oxidation-coagulation, precipitation-filtration and disinfection, which reassembles the existing operation units of waterworks.In water environment, thallium generally exists in the form of monovalent and trivalent state.The monovalent compounds of T _ 1 are stable and difficult to precipitate, while the trivalent compounds of T _ 1 are unstable and easy to precipitate.Therefore, oxidation of monovalent to trivalent prior to thallium removal is an effective way to remove thallium.The removal rate of thallium was more than 90% by the combined processes of sodium hypochlorite polyferric sulfate / polyaluminum chloride and bleaching powder polyferric sulfate / polyaluminium chloride.
【学位授予单位】：广东工业大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU991.2

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