作　　者： ; ; ; ;

机构地区： 湖南大学土木工程学院建筑安全与节能教育部重点实验室

出　　处： 《安全与环境学报》 2013年第3期78-82,共5页

摘　　要： 基于Donnan渗析原理,研究阴离子交换膜分离饮用水中的Cr（Ⅵ）,探讨受体液种类、受体液NaCl浓度、给体液初始pH值以及给体液进水流速对Cr（Ⅵ）分离的影响。结果表明,不同驱动离子条件下给体池中Cr（Ⅵ）的分离去除率从大到小依次为Cl-、HCO3-、SO24-,而离子通量从大到小依次为Cl-、SO24-、HCO3-。驱动离子宜为水合半径较小的单价Cl-,受体液应为相对廉价常见的NaCl溶液。当受体液NaCl浓度由0增加至0.100mol/L时,给体池中Cr（Ⅵ）的分离去除率变化不大,而离子通量由0显著提高至7.34×10-5mg/（cm^2.min）;进一步增加受体液NaCl浓度至0.5 mol/L,给体池中Cr（Ⅵ）的分离去除率和离子通量的增加较小。当给体液初始pH值为1.0时,给体池中Cr（Ⅵ）的分离去除率和离子通量较小,并随给体液初始pH值的增大而增大。该Cr（Ⅵ）分离过程在饮用水常规pH值范围（6.5~8.5）内均能得到较好的效果。当给体液进水流速由1.0 mL/min增加至5.0mL/min时,给体池中Cr（Ⅵ）的分离去除率由89.3%降低至73.5%,离子通量由6.25×10-5mg/（cm^2.min）增加至8.91×10-5mg/（cm^2.min）。饮用水中背景组分对Cr（Ⅵ）分离的影响不大。 This paper intends to introduce a new approach to separate chromium（Ⅵ） from drinking water with anion exchange membrane based on Donnan dialysis. For this purpose, the effect of the receiver phase composition and concentration, initial pH and the flowing rateof feed phase on Cr（Ⅵ） separation have been investigated. The experimental results show that the effect of the three kinds of driving ions on the removing efficiency of Cr（Ⅵ） follows the order of Cl- HCO3-SO2-4, while that of ion flux is found to be Cl-SO2-4 HCO3-. And, in turn, the monovalent chloride has been determined as the best driving ion among all those tested, since it has a smaller hydration radius, And its solution is relatively cheap and common to be chosen as the receiver phase. When increasing the concentration of NaCl solution from 0 to 0.100 mol/L, there would be no change to be found with the removal efficiency of Cr（Ⅵ）, though the ion flux may rise dramatically from 0 to 7.34×10-5mg/（cm^2.min）. However, if the concentration of NaCl solution rose to 0.500 mol/L, both the removal efficiency of Cr（Ⅵ） and the ion flux tends to increase slightly. We have also noticed thatthe removal efficiency and ion flux of Cr（Ⅵ） would come tothe lowest atthe pHof 1.0, and then go up with the increase of the initial pHof the feed phase. Thus, the separation of Cr（Ⅵ） with anion exchange membrane based on Donnan dialysis is likely to bring about a satisfactory separation effect in the range of conventional pHvalue （6.5-8.5） of drinkingwater. However, with the increase of flowing rate of feed phase from 1.0 mL/min to 5.0 mL/min, the removal efficiency would decrease from 89.3% to 73.5%, while the ion flux may increase from 6.25×10-5 mg/（cm^2.min） to 8.91×10-5mg/（cm^2.min）. In addition, further tests demonstrate that the background components of drinking water have only a slight adverse impact on the separation of Cr（VI）.

关 键 词： 市政工程 六价铬 阴离子交换膜 渗析

领　　域： [环境科学与工程]