混凝处理饮用水源中NOM-碘离子复合污染的研究

发布时间：2018-09-12 08:21

【摘要】：饮用水源的复合污染及其健康风险控制是当前饮用水水质净化面临的重要难题,其中对饮用水中消毒副产物的控制工作为重中之重。作为消毒副产物的主要前驱物质,水源中碘离子和天然有机物-碘离子复合污染产生的潜在健康危害十分显著。饮用水处理中工艺中,混凝能有效去除水中有机污染物,我国传统水处理工艺中混凝法具有明显的经济可行性优势。本研究以碘离子和NOM(Natural organic matter,天然有机物)-碘离子复合污染为研究对象,采用FeCl_3·6H_2O和HPAC(High poly aluminium Chloride,高聚合氯化铝)这2种混凝剂进行烧杯试验,改变混凝剂投加量、控制pH值、加入共存离子和生物聚合物等条件,考察这2种混凝剂对碘离子和NOM-碘离子复合污染的去除效果,确定相应的最佳投加量和最佳pH值条件,并通过控制混凝剂的投加量和水样的pH值,考察混凝对浊度的去除和Zeta电位的变化,探讨混凝机理。研究发现,混凝剂最佳投加量为0.5mmol/L,低pH值(pH6)有利于去除水样中碘离子且HPAC的去除率高于FeCl_3·6H_2O的去除率,去除NOM-碘离子复合污染的最佳pH值为7。共存离子对去除饮用水源中碘离子及NOM-碘离子复合污染没有影响。生物聚合物有助于去除饮用水中溶解性有机物,其投加量为1mg/L时,混凝去除NOM-碘离子复合污染的效果最佳。在本研究所采用的实验条件下,UV254和TOC(Total organic carbon,总有机碳)之间存在着高度相关关系。混凝过程中发挥主要作用的机理随着操作条件的变化而改变;对于FeCl_3·6H_2O来说,在混凝过程中,不仅电性中和发挥作用,吸附-架桥和网捕-卷扫也同样发挥作用;对于HPAC来说,在混凝过程中,吸附-架桥和网捕-卷扫发挥主要作用。保持水样呈中性有利于达到良好的混凝处理效果。
[Abstract]:The compound pollution of drinking water source and its health risk control are the important problems of drinking water quality purification at present, among which the control of disinfection by-products in drinking water is the most important. As the main precursor of disinfection by-product, the potential health hazard caused by the compound pollution of iodine ion and natural organic-iodine ion in water source is very significant. In the process of drinking water treatment, coagulation can effectively remove organic pollutants in water. In this study, iodine ion and NOM (Natural organic matter, natural organic matter)-iodine ion compound pollution as the research object, using FeCl_3 6H_2O and HPAC (High poly aluminium Chloride, high polyaluminium chloride) two kinds of coagulant to carry on the beaker experiment, change the dosage of coagulant, control the pH value, By adding coexisting ions and biopolymer, the removal effect of the two coagulants on the compound pollution of iodine ion and NOM- iodine ion was investigated, and the optimum dosage and the optimum pH value were determined. By controlling the dosage of coagulant and the pH value of water sample, the removal of turbidity and the change of Zeta potential were investigated, and the coagulation mechanism was discussed. It was found that the optimal dosage of coagulant was 0.5 mmol / L, and the low pH value (pH6) was beneficial to the removal of iodine ion in water samples, and the removal rate of HPAC was higher than that of FeCl_3 6H_2O, and the optimal pH value of removing NOM- iodide compound pollution was 7. Coexisting ions have no effect on the removal of iodine ion and NOM- iodide compound pollution in drinking water source. Biopolymer is helpful to remove dissolved organic compounds in drinking water. When the dosage of biopolymers is 1mg/L, coagulation is the best way to remove NOM- iodide compound pollution. There was a high correlation between UV254 and total organic carbon (TOC) of TOC (Total organic carbon, under the experimental conditions. The mechanism that plays a major role in the coagulation process changes with the change of the operating conditions. For FeCl_3 6H_2O, it is not only electrically neutralized, but also adsorption-bridging and trapping / scrubbing also play a role in the coagulation process; for HPAC, In the coagulation process, adsorption-bridge and net-sweep play a major role. Keeping the water sample neutral is beneficial to the good coagulation effect.
【学位授予单位】：首都经济贸易大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU991.2

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