无机稀土基吸附剂对饮用水中氟、砷的吸附研究

【作者】 焦中志；

【导师】 丁蕴铮； 杨敏；

【作者基本信息】 东北师范大学 ， 环境科学， 2002， 硕士

【摘要】 面对越来越引起人们的关注的饮用水中砷与氟的污染，研究饮用水中砷与氟的去除方法成为当前研究的热门话题。本文在综合大量资料的基础上，依据当前研究的现状发现高效吸附材料是当前水质净化处理的可行的方法及高技术环节，研发高效的吸附材料。根据稀土元素独特的物理化学性质：独特的4f电子结构，与其他元素形成稀土化合物时，配位数可在3-12之间变化，化合物的晶体结构多样化等特点研发了三种稀土基无机化合物吸附剂：水合氧化锆，水合氧化铈，CTA吸附剂。并对其物理化学特征、吸附性能、以及吸附机理进行探讨。结果表明：(1)pH值对吸附剂的吸附容量影响较大，在酸性范围有利于吸附，而在碱性范围吸附容量降低很大，在pH值为11以上时几乎没有吸附；(2)采用Freundlich型与Langmiur型吸附等温模式能够很好的描述吸附剂对氟和砷的吸附行为；(3)吸附速度快；(4)脱附简单，采用合适浓度的氢氧化钠便可将已吸附的物质洗脱，且吸附剂的重复利用性好：(5)与常用的吸附剂——活性氧化铝进行吸附比较，结果表明这三种稀土基无机化合物吸附剂对砷、氟的吸附能力要强、去除效果好、适应的pH范围广；(6)通过柱式动态模拟试验摸索出适合现场试验的吸附条件及吸附容量。 采用红外光谱、扫描电镜、X-射线衍射、电位滴定等现代分析测试手段对吸附剂的吸附机理进行了推测，结果表明：吸附剂本身具有羟基以及水合后的羟基对水中砷、氟的去除起重要作用； 考虑到实际应用，将粉末吸附剂成型，成型后的吸附剂进行试验室动态模拟试验，结果表明：稀土基无机化合物吸附剂对氟、砷吸附容量大，运行周期长，去除效果好，再生容易等优点，所以它们是具有高效、经济性的吸附材料。更多还原

【Abstract】 Arsenic pollution and fluorine pollution in drinking water attract more and more people’s attention. Research and develop new effective adsorbent is the focus for the present. This dissertation compiled many data, we find that high effective adsorbent is practical in water purification, and that to develop this adsorbent need high technique. According to character of rare earth’s specific physical chemistry, such as specific electron composition, large atom magnetic torque, ligand range from 3 to 12 when combined with other elements, diversity of compound crystal structure, we develop three adsorbent: hydrous Zirconium, hydrous Cerium and CTA. We made expriment on their physical chemistry character, adsorbent property and adsorbent mechanism. The experiment results: 1. impaction of pH is very large on adsorption capacity, in acid water it conducive to adsorption but in alkli it declines capacity and when pH value is higher than 11 the adsorbent can hardly adsorb; 2.we adopt Freundlich Equation and longmiur equation to depict adsorbent’s adsorption. 3.high adsorption speed 4.it is simple to desorpt and use proper sodium hydroxide; 5.we compared with alumigel and find that the three adsorbent can adsorb arsenic and fluorine very large and effectively and they can use in wide pH value range. 6.Through column experiment we grope the proper condition and adsorption capacity.By virue of contemporary analytical machine such as infrared analysis, EMS, XRD, and potentiometric titration, we speculated the adsorption mechanism: the adsorbent proper hydroxyl plays an important role in eliminating arsenic and fluorine.To make pratical material we made a further step to mould the powder into granule to imitate on- the -spot experiment. The result showed that rare earth based adsorbent can adsorb well, eradicate effectively and regenerate easily, so they are effective and economical adsorbent.更多还原