液膜分离技术在金属离子分离方面的应用研究

【作者】 余晓皎；

【导师】 周孝德； 姚秉华；

【作者基本信息】 西安理工大学 ， 环境工程， 2001， 硕士

【摘要】 工业废水中重金属离子以其自身的污染特点对环境造成的巨大危害而倍受环保部门的高度重视。由于传统的处理方法处理过程复杂，费用高而难以使其废水得到有效治理，因此，开发高效节能且具有环境效益和经济效益的工业废水处理技术势在必行。 液膜分离作为一项简单、快速、高效、选择性好、经济节能的新兴分离、浓缩技术，被广泛用于工业废水中重金属离子的处理研究，实现了工业废水中重金属离子的提取与分离，但在工业化应用中受到了一定的限制。一方面由于液膜自身的构型缺陷如乳化液膜的制乳与破乳矛盾、支撑液膜的膜稳定性问题没有得到很好解决；另一方面是由干液膜分离的载体种类较少，选择性不高等。因此，本论文在前人研究的基础上，针对目前普遍关注的环境中重金属污染问题，籍助选择性好、荤取率高的有机磷酸化合物，在进行革取平衡研究的同时，针对乳化液膜和支撑体液膜分离存在的问题，选择大块液膜分离体系，对铜、铅金属离子的液膜传输过程进行研究。 烷基磷酸是一种高效革取剂。本论文首先针对革取溶剂对烷基磷酸苹合物组成的影响，研究了则(NH4)2SO4 介质中二(o－乙基己基)磷酸──NaphtezoI M 溶液对Cu(Ⅱ)和Zn(Ⅱ)的萃取平衡，测得其半萃取pH(1/2)值分别为2.24和3.73。籍助斜率分析和数值计算确定了萃合物的组成分别为(ZnR2·2HR)2，(ZnR2·6HR)2，(CuRo·2HR)2和(CuR2·6HR)2，并计算了相应的萃取平衡常数。其次，自行设计制作液膜分离装置，以2－乙基己基磷酸单－2－乙基己基酯(PC－88A)为膜载体，三氯甲烷作膜溶剂，分别对铜、铅金属离子的液膜迁移行为、迁移速率及影响迁移的各种因素进行了较为系统的研究，测定了不同载体浓度下的半迁移pH(1/2)值。根据液膜迁移方程，利用斜率分析法分别测定了不同温度条件下铜、铅离子的渗透系数，以及有关的热力学参数，确定了液膜分离铜、铅金属离子的最佳工艺条件。更多还原

【Abstract】 In recent years, environment scientists pay much attention to the environmenteffects of the heavy metal ions in industrial wastewater because some of metal ions cancause the heavy damages to the health of human and biological balance. Therefore, it isvery necessary to develop a new wastewater treating technique with high efficiency,saving energy and environment protection.The separation technique with liquid membrane containing a mobile carrier is anovel technique with simple, high efficiency and good selective, which has been widelyapplied to the separation and concentration of metal ions, removal of phenol fromwastewater, and biological application such as anificial Kidney. Howevef, the techniquemeet some limitations such as the structure defects and membrane carrier loss ofsupported liquid membranes, and the conflict between emulsion and de-emulsion ofemulsion membranes. Therefore, the bulk liquid membrane containingorganophosphorus acid was applied to the transfer investigations of copper(Ⅱ) andzinc(Ⅱ), and avoided effectively the problems above in this work. The experimentalresults are described as below:(1) The extraction behavior of copper(Ⅱ) and zinc(Ⅱ) from 1.0 mol dm(-3)ammonium sulfate solution into Naphtezol M containing bis (2-ethylhexyl )phosphinicacid has been studied as a function of pH and extractant concentration. The pH(1/2) valueswere determined to be 2.24 and 3.73 for Zinc(Ⅱ) and Copper(Ⅱ), respectively. The datehave been analyzed numerically to determine the stoichiometry of extracted specieswere found to be (ZnR2·2HR)2 and (ZnR2·6HR)2 for Zinc(Ⅱ) and (CuR2·2HR)2 and(cuR2· 6HR)2 for coPPer(Ⅱ), resPectively.(2) The transfer rate of coPPer(Ⅱ) and lead(Ⅱ) from aqueous feed sulfate solutionto inorganic acid strip soluton through a bulk liquid membrane consisting2-ethylhexylphosphonic acid mono-2-ethylhexyl ester(PC-88A) as membran carrierand CHCl3 as membrane solvent, was studied, respectively. The influence of the pHvalues in external aqueous phase, PC-88A carrier concentrations, experimentaltemperatures and the concentrations of inorganic acid in internal aqueous, wasinvestigated. The half-transfer pH(1/2) values were determined under differentconcentrations of the carrier. The permeability coefficients and the values ofthermodynamics functions Δhθ and Δsθ of copper(Ⅱ) and lead(Ⅱ) through bulk liquidmembrane have been experimentally measured.更多还原