透析膜辅助氧化石墨烯分散液吸附分离水中低浓度稀土离子的研究

发布时间：2018-03-15 02:10

本文选题：氧化石墨烯分散液　切入点：稀土分离　出处：《南昌大学》2015年硕士论文　论文类型：学位论文

【摘要】：本论文针对当前南方稀土矿山废水中低浓度稀土离子高效分离技术的瓶颈,特别是应用纳米吸附剂普遍存在的二次污染问题,基于大分子氧化石墨烯胶体的超强吸附功能和透析膜的筛分性能,创造性地提出了氧化石墨烯胶体与透析膜组合用于低浓度稀土离子的吸附分离的方法,系统研究了时间、pH值、温度、离子强度、氧化石墨烯的片径对吸附平衡的影响,建立了吸附过程的热力/动力学模型,研究了脱附过程主要影响因素,如pH值、离子强度、脱附时间等,并对稀土离子透过透析膜在氧化石墨烯上的脱附进行了动力学分析,最后评价了氧化石墨烯的再生循环使用性能。研究表明,在pH=5.9±0.1,T=303K的条件下,微米氧化石墨烯(MGO)对Gd3+、Y3+、Eu3+和Tb3+的最大吸附量分别是281.03 mg/g、179.86 mg/g、267.91 mg/g和265.62 mg/g,远高于文献报道的其他吸附材料,而亚微米氧化石墨烯(SMGO)分别为354.91 mg/g、340.54 mg/g、374.32 mg/g和366.82 mg/g。溶液的pH是影响GO吸附稀土离子性能的关键因素。热力/动力学分析显示GO对这4种稀土离子吸附是一个吸热的、自发的单层吸附过程,符合拟二级动力学模型和Langmuir吸附模型。脱附研究表明Gd3+、Y3+、Eu3+和Tb3+在氧化石墨烯上脱附均符合拟二级脱附动力学模型,其中脱附液的pH值是影响脱附的关键因素。在pH=0.9的条件下,Gd3+、Y3+、Eu3+和Tb3+最大脱附率分别为90.00%、92.11%、91.21%和90.09%。有意义的是在连续吸附-脱附4次后,脱附率仍分别达到85.15%、74.26%、76.82%和75.27%,吸附容量仍分别达到220.23 mg/g、138.73mg/g、230.45 mg/g和216.33 mg/g。总之,氧化石墨烯(GO)是一种高性能的、可再生的分离富集稀土离子的吸附剂。特别有意义的是GO与透析膜组合方便地解决纳米吸附剂分离困难造成的二次污染问题,为纳米吸附剂实际应用于水污染处理和资源回收提供了一条新思路。
[Abstract]:This paper aims at the bottleneck of high efficiency separation technology of low concentration rare earth ions in waste water of rare earth mines in southern China, especially the secondary pollution problem of the application of nanometer adsorbent. Based on the super adsorption function of macromolecular graphene oxide colloid and the screening performance of dialysis membrane, the method of combining graphene oxide colloid with dialysis membrane for the adsorption and separation of rare earth ions with low concentration was creatively put forward, and the pH value was systematically studied. The influence of temperature, ionic strength and the diameter of graphene oxide on the adsorption equilibrium was studied. The thermodynamic / kinetic model of the adsorption process was established, and the main factors affecting the desorption process, such as pH value, ionic strength, desorption time and so on, were studied. The desorption of rare earth ions through dialysis membrane on graphene oxide was analyzed, and the regeneration and recycle performance of graphene oxide was evaluated. The results showed that under the condition of pH=5.9 卤0.1 TX 303K, the desorption of rare earth ions on graphene oxide was studied. The maximum adsorption capacity of micron graphene oxide (MGOO) to Gd3 Y3 + EU3 and Tb3 are 281.03 mg / g, 179.86 mg / g, 267.91 mg/g and 265.62 mg / g, respectively, which is much higher than that of other adsorption materials reported in the literature. The submicron graphene oxide (SMGOO) was 354.91 mg / g / g ~ (34) mg / g ~ (-1) ~ (34. 54) mg / g ~ (3 +) and 366.82 mg / g / g respectively. The pH value of the solution was the key factor affecting the performance of go adsorption of rare earth ions. Thermodynamic and kinetic analysis showed that go adsorption of these four rare earth ions was endothermic. The spontaneous monolayer adsorption process was in accordance with the pseudo-second-order kinetic model and the Langmuir adsorption model. The desorption results showed that the desorption of Gd3 _ (3) O _ (3) EU _ (3) and Tb3 on graphene oxide was in accordance with the pseudo-second-order desorption kinetic model. The pH value of desorption solution is the key factor affecting desorption. The maximum desorption rates of Gd3, Y3, EU3 and Tb3 are 91.21% and 90.09% respectively under the condition of pH=0.9. It is significant that the desorption rate is 91.21% and 90.09% respectively under the condition of pH=0.9. The desorption rate is still 85.15% and 74.26% and 75.27%, respectively, and the adsorption capacity is still 220.23 mg / g / g, 138.73 mg / g / g / g, 230.45 mg/g and 216.33 mg / g / g, respectively. In short, graphene oxide is a kind of high performance. Renewable adsorbents for the separation and enrichment of rare earth ions. In particular, the combination of go and dialysis membranes can easily solve the problem of secondary pollution caused by the difficulty of separation of nano-adsorbents. It provides a new idea for the application of nanometer adsorbent in water pollution treatment and resource recovery.
【学位授予单位】：南昌大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ028.8

【共引文献】