不同价态阳离子盐改性沸石吸附氨氮能力差异

发布时间：2018-01-20 15:20

本文关键词： 沸石盐改性阳离子价态阳离子交换容量氨氮吸附　出处：《湖南大学学报(自然科学版)》2016年06期 　论文类型：期刊论文

【摘要】：采用5种不同价态阳离子盐对天然斜发沸石进行改性,通过SEM,EDS,ICP以及氮吸附分析仪等测试手段对改性前后的沸石颗粒进行表征,发现不同价态阳离子和相同价态不同阳离子的盐改性沸石后对其物化性质和应用性能均会产生影响.EDS及ICP测试发现由于离子交换作用改性后沸石中5种盐对应的金属阳离子含量均会升高,其中KCl改性沸石中钾元素含量增加量最多.比表面积与孔径分布测试结果发现随着阳离子价态升高,沸石比表面积下降幅度逐渐增大,其中一价钾盐的改性沸石比表面积下降幅度最小为33.9m~2/g,三价铝盐下降幅度最大为29.27m~2/g;而改性沸石孔体积变化规律有所不同,其中一价盐改性沸石介孔体积增加量最大、大孔体积减少量最多.对不同价态阳离子盐改性沸石进行了阳离子交换容量和污水脱氮能力测试,结果表明,其阳离子交换容量和脱氮能力大小排序为:NaClAlCl_3CaCl_2MgCl_2KCl.说明改性沸石的污水脱氮能力与其阳离子交换容量呈正相关关系,但是阳离子价态的高低与改性沸石的阳离子交换容量、比表面积、孔体积和脱氮能力并不是正相关关系.
[Abstract]:Five kinds of cationic salts with different valence were used to modify natural clinoptilolite. The zeolite particles before and after modification were characterized by means of SEM-EDSICP and nitrogen adsorption analyzer. It was found that the modified zeolite with different valence cations and different cations with the same valence would have an effect on the physicochemical properties and application properties of zeolite. EDS and ICP test showed that the modified zeolite was modified by ion exchange. The content of metal cations corresponding to the species salt increased. The increase of potassium content in KCl modified zeolite was the most. The results of specific surface area and pore size distribution showed that the specific surface area decreased gradually with the increase of cationic valence state. The specific surface area of the modified zeolites with monovalent potassium salt decreased by 33.9 mg / g, and that of Al trivalent salts decreased by 29.27mg / g, respectively, and the specific surface area of the modified zeolites decreased by a minimum of 33.9 mg / g. The change of pore volume of modified zeolite is different, among which the increase of mesoporous volume of monovalent salt modified zeolite is the largest. The cation exchange capacity and denitrification capacity of wastewater were tested on zeolite modified with different valence cationic salts. The order of cation exchange capacity and denitrification capacity is:. NaClAlCl3CaCl2MgCl2KCl. it shows that the denitrification capacity of modified zeolite is positively related to its cation exchange capacity. However, the cationic valence state is not positively correlated with the cation exchange capacity, specific surface area, pore volume and denitrification capacity of the modified zeolite.
【作者单位】：北京科技大学土木与环境工程学院;北京科技大学工业典型污染物资源化处理北京市重点实验室;
【基金】：国家自然科学基金资助项目(51174017)~~
【分类号】：X703
【正文快照】： 沸石是一种分布较多的天然矿物,因其特殊的单斜晶体结构,具有特异性吸附作用,已被广泛应用到水处理领域.天然沸石形成时由于受地质条件及环境条件的影响,孔道分布不均匀且相互不连通,孔道含杂质也较多.为了提高其吸附水中氨氮等污染物的能力,目前常用的沸石改性方法有焙烧改性

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