【作者】 姚红娟；

【导师】 王晓琳；

【作者基本信息】 清华大学 ， 应用化学， 2003， 硕士

【摘要】 本文选用NTR7450（Nitto Denko, Japan）和NF270（DOW Chemical Corporation, USA）两种纳滤膜分离工业合成的水溶性荧光染料溶液，选择出透过通量大、除盐效果好和染料截留率高的纳滤膜，对该工业染料原液脱盐和浓缩的间歇渗滤过程进行研究。在温度25℃和压力1.0MPa下，膜对染料截留率达到100％，经过六次加水浓缩的间歇渗滤操作后，料液中NaCl浓度从0.214mol/L降到0.0025mol/L，料液被浓缩了2.6倍。说明纳滤膜的间歇渗滤操作过程能够实现染料溶液的脱盐和浓缩。本文的另一部分工作是对于该荧光染料体系，提出了能够达到脱盐和浓缩目的的三种分离纯化工艺过程，即间歇恒容渗滤过程、预浓缩-连续恒容渗滤-后浓缩组合过程和连续变容渗滤过程，并对这三个过程进行了模拟计算和比较，用于预测过程中各参数的变化，确定过程时间最短和水的消耗量最小时的工艺参数，为工业应用提供理论指导。（1）对于间歇恒容渗滤过程，通过研究不同的浓缩倍数（1.25、2和3）和膜对盐的截留率R对过程参数的影响，发现达到相同的除盐要求和染料纯度时，浓缩倍数较小和R较大时，都会使总的水消耗量较大，过程时间较长。（2）对于预浓缩-连续恒容渗滤-后浓缩组合过程，通过研究不同的预浓缩倍数（1.25、2和3）和R对过程参数的影响，发现达到相同除盐要求和染料纯度时，预浓缩2倍的组合过程所需总过程时间最短，而水的消耗量与预浓缩倍数、R和除盐要求有关。（3）对于连续变容渗滤过程，研究了不同的最终染料浓度、除盐要求和R对过程参数的影响。结果表明，如果最终除盐要求相同而染料浓度越高，需要较长的过程时间和较小的水消耗量；如果相同染料浓度相同而除盐要求越高，需要的较长过程时间和较大的水消耗量。利用以上三个过程进行染料纯化时，达到相同的脱盐和浓缩目标值，间歇恒容渗滤过程和连续变容渗滤过程所需的过程时间和水消耗量相同，说明在达到目标值的过程中，它们的平均透过通量是相同的。预浓缩2倍的组合过程需要较短的过程时间和较小的水消耗量，其水消耗量取决于连续恒容渗滤阶段。更多还原

【Abstract】 Permeation experiments of aqueous industrial fluorescent dye solution were carried out by using the two kinds of NF membranes, which were NF270 (DOW Chemical Corporation, USA) and NTR7450 (Nitto Denko, Japan) membranes, in order to chose the nanofiltration membrane having high permeation flux, low rejection of NaCl component and high rejection of dye. Thus, the NF270 membrane in the operation mode of batch diafiltration was used for the concentration and desalination of aqueous dye solution. Under temperature 25℃ and applied pressure of 1.0MPa, observed rejection of dye component reached 100%. After six-stage batch diafiltration operation, concentration of dye increased 2.6 times, and concentration of NaCl decreased from 0.214mol/L to 0.0025mol/L. The experimental results showed that nanofiltration membrane NF270 in batch diafiltration operation mode was applicable in desalination and concentration of aqueous dye solution. In present dissertation, for the purpose of desalination and concentration of this aqueous dye solution, batch constant volume diafiltration process, combined process of preconcentration phase- continuous constant volume diafiltration phase- post concentration phase and continuous variable volume diafiltration process were studied. These separation and purification processes were simulated and derived to predict the changes of process parameters. The work will provide useful theoretical guide for the engineering application and embody its value. (1) The simulation of batch constant volume diafiltration process was used to determine the effects of the volume concentration factor (1.25, 2, 3) or volumes of adding water （0.2V0 , 0.5V0 , 2/3V0）and rejection of NaCl component on desalting and purifying of dye solution. The simulative results suggested that to obtain the same concentration of NaCl and purity of dye in the retentate, the less volume concentration factor and the higher rejection of salt, the more volume of required adding water. With the increasing of repeated concentration-dilution operation times, the efficiency of removal of salt was descreased. (2) The simulation of combined process of three phases was used to<WP=9>determine the effects of the volume concentration factor in preconcentration phase (1.25, 2, 3) and rejection of NaCl component on the process parameters, and the process time was optimized. For the minimum process time, the optimum value of dye concentration at diafiltration was 11.8%. Thus, to obtain the same concentration of NaCl and dye component in the retentate, the optimum appears to be a combined process where the feed was first preconcentrated about 2 times by nanofiltration, followed by continuous constant volume diafiltration and postconcentration. The required volume of adding water depended on volume concentration factor in preconcentration phase, salt rejection and desired salt concentration in the retentate. (3) The simulation of continuous variable volume diafiltration process was to discuss the effect of final concentration of dye and salt in the retentate and salt rejection on the process performance. The simulative results showed that if the same salt concentration are obtained in the retentate, the higher the dye concentration, the longer the process time and the less volume of required adding water; and if the same dye concentration are obtained in the retentate, the lower the salt concentration, the longer the process time and the more required volume of adding water.When the same dye and salt concentration (Cdye/Cdye,0 = 3, Csalt,0/Csalt = 81) are achieved, these three process were compared. The total process time and required volume of adding water in the batch constant volume diafiltration process were identical with the continuous variable volume diafiltration process, which show that their average permeation fluxes are also same. However, compared with these two processes, the combined process of three phases required the minimum process time when the feed was preconcentrated about 2 times. In the combined process, the required volu更多还原