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反萃分散组合液膜体系和支撑液膜体系迁移和分离金属离子的研究

Study of Transport and Separation of Metal Ions with Strip Dispersion Hybrid Liquid Membrane and Supported Liquid Membrane

【作者】 谷淑湘

【导师】 何鼎胜;

【作者基本信息】 湖南师范大学 , 分析化学, 2007, 硕士

【摘要】 液膜分离技术具有传质速度快、选择性好、分离效率高、操作简便和易于实现自动化等特点,在分离和富集废水中的金属离子和有机污染物方面,展示了优良的性能。本文回顾了液膜的发展简史,介绍了液膜的分类、分离机理和特点。通过讨论液膜两种基本构型即支撑液膜和乳化液膜的形成、应用、不足以及对该两种液膜的不稳定性所作的改进,阐述了在科研和工业中发展液膜新构型的必要性,并设计了几种典型的反萃分散组合液膜(SDHLM),考察了它们在废水处理中的实用性。具体工作包括以下几个方面:1、系统地研究了四个反萃分散组合液膜体系,即三正辛胺—仲辛醇—煤油—CH3COONH4体系迁移镉和镉锌分离;PMBP—OT—液体石蜡—二甲苯—HCl体系迁移铜和铜锌分离;TRPO—P204—液体石蜡—煤油—NaOH体系同时迁移镉和氰离子;N902—煤油—HCl体系分离铜锌。在不同的体系中考察了载体浓度,料液pH值,反萃剂浓度,反萃分散相体积比,料液流量,反萃分散相流量以及金属离子浓度等各种条件对迁移和分离的影响,优化了实验条件参数。2、与支撑液膜(SLM)在上坡迁移、金属离子分离、膜液中载体的流失等方面进行了系统地比较。3、研究了反萃分散组合液膜体系中双载体对Cd2+和CN-的同时迁移作用。由以上工作得出:反萃分散组合液膜体系中的膜溶液可以对支撑体微孔中膜液的损失进行补充,增加膜的稳定性,减小支撑液膜的液膜相从支撑体微孔中的流失,延长膜的使用寿命;反萃分散组合液膜体系中有机相与水相反萃液的搅拌混合提供了反萃过程中的极大传质表面积,因而使反萃效率大为提高,这种高效反萃提高了金属离子迁移通量,同时得到高浓度溶质的反萃液;反萃分散组合液膜体系中没有使用乳化剂和破乳装置,减少操作费用和初期投资,同时简化了操作步骤。实验表明,SDHLM在膜选择性、膜的使用寿命以及膜的渗透速度等方面都优于SLM。

【Abstract】 Liquid membrane separation technology has exhibited excellent characters on separation and enriching metal ions and organic pollutant in the industrial wastewaters due to their fast mass transport, great selectivity, high separation efficiency, convenient operation, and easy automatization. This text briefly looked back the development history of the liquid membrane and introduced the classification, separation mechanism and the characteristics of the liquid membrane. By discussing the formation, applications, shortages and the improvement to the instability of supported liquid membrane and emulsion liquid membrane, the experimenters expounded the necessity of developing new configuration of liquid membrane, in scientific research and industry operation, and designed some new types of strip dispersion hybrid liquid membrane (SDHLM), and investigated their practicality in industrial wastewater treatment.The concrete work includes:(1)Four strip dispersion hybrid liquid membrane systems were studied systematically. They are: transport of Cd2+ and separation of Cd2+ from Zn2+ with tri-n-octylamine-secondary octyl alcohol( )-kerosene-CH3COONH4 system, transport of Cu2+ and separation of Cu2+ from Zn2+ with PMBP-OT-paraffine -xylene-HC1 system, separation of Cd2+ and CN- at same time with TROP-P204-paraffine -kerosene -NaOH system, and separation of Cu2+ from Zn2+ with N902-kerosene-HC1 system. These factors of carrier concentration, pH in feed solution, stripping solution concentration, volume ratio of strip dispersion, flux of the feed solution, and flux of the strip dispersion that influence on ions transport and separation were investigated in different system, and optimized experimental conditions.(2)The study made the comparision between strip dispersion hybrid liquid membrane and supported liquid membrane (SLM), as in uphill transport, ions separation, carrier loss in membrane phase.(3)The simultaneous separation of Cd2+ and CN- was investigated with double carriers in strip dispersion hybrid liquid membranes.From the above work, we drew the following conclusions: the strip dispersion hybrid liquid membrane system can constantly supply the loss of the carrier to the microporous support, and enhanced the stability of membrane. The mixed stirring between the organic phase and the strip phase provided an extra mass transfer surface in addition to the surface given by the microporous film, thus greatly improving the efficiency of stripping.The high efficience of stripping increases ions transport flux. Transport and recovery of ions from industrial wastewaters are proved practical with the strip dispersion hybrid liquid membrane. In the experimental comparison of transport flux, permeability coefficient; recovery percentage or oncentration of solute in stripping solution, efficiency of uphill transport, loss of membrane solution, and separation efficiency of embrane for two types of liquid membrane, SDHLM has superiority over SLM.

  • 【分类号】TQ028.8
  • 【下载频次】64
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