硼特效配位吸附树脂对反渗透海水淡化中硼的吸附研究

发布时间：2018-04-11 22:35

本文选题：Amberlite + IRA-743树脂　；参考：《天津工业大学》2017年硕士论文

【摘要】：水是人类生存之源,生活之基。离开了水,就像离开空气一样,很难坚持多久。进入21世纪,随着经济的发展,社会的进步,如今我们的水资源已经被污染的惨不忍睹,能够被我们引用的淡水资源少之更少,饮用水中的大量无机有机污染物已经检测出来,严重威胁着我们的饮用水和再生水领域。海水淡化是一种新型的造水、节水技术,能够缓解淡水资源严重不足的问题,在世界和中国沿海地区得到广泛的推广、应用,同时也产生大量的浓海水。硼酸是一种特殊的污染物,由于其分子量比较小,在反渗透海水淡化中能够像水分子一样自由地透过反渗透膜,影响了出水水质。一般反渗透海水淡化的水中硼酸的浓度在0.9mg/L,我国的水质标准是0.5mg/L,因此为了达到我国的饮用水标准,需要与其它方法联合起来。本文是选用的AmberliteIRA-743树脂,通过扫描电镜、红外光谱分析了其表面结构和内部所含的官能团,选用的Amberlite IRA-743树脂的投加量是4g,吸附时间为200min。实验结果表明,在1mg/L的硼酸溶液中,Amberlite IRA-743树脂为4g时,对硼的去除效果能够达到90%以上。其次,分别从吸附热力学、吸附动力学、吸附再生性三个方面探讨了Amberlite IRA-743树脂对反渗透海水淡化中硼的去除研究。从Amberlite IRA-743树脂吸附硼的热力学分析得出,吸附等温线符合Freundlich吸附等温线模型,其R2达到0.999以上;从吸附动力学研究发现,Amberlite IRA-743树脂吸附硼的动力学吸附结果研究符合准二级动力学;根据Amberlite IRA-743树脂的再生和多周期吸附硼酸的实验可得,其离子交换的贡献稍微大于微孔吸附,大概占到整个吸附过程的55%,微孔吸附占45%左右,物理吸附也占有一大部分。另外,还对温度和pH值的变化影响Amberlite IRA-743树脂吸附硼酸的效果进行了研究。结果发现,温度对于Amberlite IRA-743吸附硼的过程影响不大,升温并没有加快加大树脂的吸附效果;pH越高吸附率就越高,pH在8～11时对硼的吸附容量最大,达到85%以上。由于对出水pH有一定的要求,所以选择pH为8～9之间最佳。最后,本次实验还考虑到了腐殖酸(HA)的存在对Amberlite IRA-743树脂对反渗透海水淡化中硼的去除效果的影响。在天然水体中,腐殖酸是一种典型的有机物。研究发现,HA自身对硼酸有一定的吸附作用,但是在HA的存在下,Amberlite IRA-743树脂对硼的去除不但没有促进作用,而且还有一定的抑制作用。
[Abstract]:Water is the source of human existence and the basis of life.Leaving the water is like leaving the air. It's hard to hold out for long.In the 21st century, with the development of our economy and the progress of our society, our water resources have been polluted, the fresh water resources that we can quote are even less, and a large number of inorganic organic pollutants in drinking water have been detected.It is a serious threat to our drinking and reclaimed water fields.Seawater desalination is a new water-making and water-saving technology, which can alleviate the serious shortage of fresh water resources. It has been widely used in the world and coastal areas of China, and has also produced a large amount of concentrated seawater.Boric acid is a special pollutant. Because of its small molecular weight, boric acid can permeate the reverse osmosis membrane as freely as water molecules in reverse osmosis seawater desalination, which affects the effluent quality.The concentration of boric acid in general reverse osmosis seawater desalination is 0. 9 mg / L, and the water quality standard in China is 0. 5 mg / L, so in order to reach the drinking water standard of our country, it is necessary to combine with other methods.The surface structure and functional groups of AmberliteIRA-743 resin were analyzed by scanning electron microscope and infrared spectroscopy. The dosage of Amberlite IRA-743 resin was 4 g and the adsorption time was 200 min.The experimental results show that the removal efficiency of boron can reach more than 90% when the amberlite IRA-743 resin is 4 g in the boric acid solution of 1mg/L.Secondly, the removal of boron from reverse osmosis seawater desalination by Amberlite IRA-743 resin was studied from three aspects: adsorption thermodynamics, adsorption kinetics and adsorption regeneration.The thermodynamic analysis of boron adsorption by Amberlite IRA-743 resin shows that the adsorption isotherm accords with the model of Freundlich adsorption isotherm, and its R2 is more than 0.999. From the study of adsorption kinetics, it is found that the kinetic adsorption results of boron adsorbed by IRA-743 resin agree with the quasi-second-order kinetics.According to the regeneration of Amberlite IRA-743 resin and the experiment of multi-period adsorption of boric acid, the contribution of ion exchange is slightly greater than that of micropore adsorption, accounting for about 55% of the whole adsorption process, about 45% of micropore adsorption, and a large part of physical adsorption.In addition, the effect of temperature and pH on the adsorption of boric acid by Amberlite IRA-743 resin was studied.Due to the certain requirement of effluent pH, the optimum pH value is between 8 and 9.Finally, the effect of the presence of humic acid on the removal of boron in reverse osmosis seawater desalination by Amberlite IRA-743 resin was considered.Humic acid is a typical organic substance in natural water.It was found that the boric acid could be adsorbed by the HA itself, but the removal of boron by Amberlite IRA-743 resin was not only not promoted, but also inhibited to some extent in the presence of HA.
【学位授予单位】：天津工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P747

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