【作者】 贾丽；

【导师】 姚杰；

【作者基本信息】 哈尔滨工业大学 ， 环境工程， 2011， 硕士

【摘要】 煤气化废水是一种有毒有害的、难生物降解的工业废水,废水中含有大量的酚类物质,具有较高的回收价值。支撑液膜萃取技术是结合了溶剂萃取和膜分离的新型分离技术,具有萃取剂用量小、损失少,萃取效率高、所需级数少,运行成本低、能耗少,二次污染小等优点,具有广阔的研究和应用前景。本论文以磷酸三丁酯（TBP）为萃取剂,以煤油为膜溶剂,以氢氧化钠溶液为反萃取剂,以PVDF为膜材料,采用中空纤维支撑液膜萃取法处理煤气化废水,并回收其中的酚类物质。考察了传质方式、反萃相浓度、相比、两相流速、膜组件装填因子、温度等操作条件对萃取效率的影响,得到了最优操作条件;分析了支撑液膜萃取酚的传质过程,建立了总传质系数模型,计算了传质过程的料液相、膜相和反萃相的分传质系数及总传质系数;并对实验逐步放大,对放大实验的操作条件进行了一定程度的优化。支撑液膜萃取煤气化废水的最优操作条件为:萃取体系为20%TBP-煤油、膜组件竖直放置、并流传质、反萃相浓度为0.1mol/L、相比为0、料液相流速为5L/h、反萃相流速为5L/h、膜组件装填因子为19%、温度为常温,在此条件下,萃取达到平衡所需时间为50min,萃取率为86.2%,出水酚浓度为98.64mg/L。建立了稳态下相应简化的支撑液膜萃取酚过程的总传质系数模型,计算得到稳态下料液相、膜相和反萃相的分传质系数及总传质系数:k_w=7.066×10^-6m/s,k_m=1.383×10^-6m/s,k_s=2.123×10^-5m/s,K_W=4.235×10^-6m/s,说明料液相和膜相传质阻力在总传质阻力中所占比重较大。实验放大过程比较成功,针对250L煤气化废水的处理,实验能达到较好的萃取效果,其最优操作条件为:反萃相浓度0.10mol/L、相比1:200、料液相流速为100 L/h、反萃相流速为60L/h,在此条件下,达到萃取平衡所需时间为240min,萃取率为75.71%,出水中酚浓度为262.73mg/L。更多还原

【Abstract】 Coal gasification wastewater is a kind of toxic and hazardous industrial wastewater, which contains high concentrations of phenolic compounds with high recovery value. Supported liquid membrane extraction technique is a new separation technology combined solvent extraction and membrane separation, with advantages of a small extractant use and low extractant loss, high extraction efficiency, low running costs、energy consumption and secondary pollution, showing broad research and application prospects.Hollow Fiber Supported liquid membrane （HFSLM） extraction was introduced to treat coal gasification wastewater to recover the phenolic compounds, with tributyl phosphate （TBP） as carrier, kerosene as the membrane solvent, sodium hydroxide solution as the stripping agent and PVDF as the membrane material. Many factors having strong impact on the extraction efficiency were studied in detail, including the mass transfer mode, two-phase flow rate, membrane filling factor, temperature and the optimal operating conditions were obtained. On this basis, the mass transfer process of HFSLM extraction of phenol was analyzed, the overall mass transfer coefficient model was stablished and the mass transfer coefficient of feed solution, membrane phase and stripping phase and the sub-total mass transfer coefficient were calculated. The experiments were gradually enlarged and the operating conditions were optimized for a certain degree.The optimum operating conditions of HFSLM extraction of coal gasification wastewater were: extraction system of 20% TBP-kerosene, membrane vertically, and mass transfer, stripping phase concentration of 0.1mol/L, feed solution flow rate of 5L/h, stripping phase flow rate of 5L/h, the membrane component filling factor of 19%, experiment temperature of 300K. Under the optimum operating conditions, the time required to reach equilibrium for the extraction is 50min, extraction rate of phenol is 86.2% and the phenol concentration of effluent is 98.64mg/L.The paper established the mass transfer coefficient model of HFSLM extraction of phenol and calculated the mass transfer coefficient of liquid material, membrane phase and stripping phase and the sub-total mass transfer coefficient: k_w=8.044×10^-6 m/s, k_m=5.333×10^-6m/s, k_s=1.404×10^-5m/s, K_w=4.942×10^-6m/s. It showed that the mass transfer resistance of feed solution and membrane phase share in total mass transfer resistanceThe pilot-scale experiments was carried out successfully and the optimum operating conditions of HFSLM extraction for 250L coal gasification wastewater were: stripping phase concentration of 0.1mol/L, phase ratio of 1:200, feed solution flow rate of 100L/h, stripping phase flow rate of 60L/h. Under the optimal operating conditions, the time required to reach extraction equilibrium is 240min, the extraction rate of phenol is 75.71% and the phenol concentration of effluent is 262.73mg/L.更多还原