魏凤,徐怀洲,向春晓,刘颖,袁林,杨刚.不同前处理方式下钠基蒙脱石对重金属镉的吸附研究[J].农业环境科学学报,2018,37(3):456-463. |
不同前处理方式下钠基蒙脱石对重金属镉的吸附研究 |
Research on Ca2+ adsorption using Na-montmorillonite through different pretreatment methods |
投稿时间:2017-08-03 |
DOI:10.11654/jaes.2017-1064 |
中文关键词: 钠基蒙脱石 前处理 表面特性 吸附 镉 |
英文关键词: Na-montmorillonite pretreatment surface property adsorption cadmium |
基金项目:国家自然科学基金青年科学基金项目(21507036);四川省教育厅重点项目(16ZA0043);四川省科技厅重点项目(2015SZ0007) |
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中文摘要: |
采用不同前处理方式(100℃烘干、200℃煅烧、300℃煅烧、冻干)制备出钠基蒙脱石,通过表征手段分析了其理化性质差异,并考察了其对溶液中Cd2+的吸附行为,以探究不同前处理方式对钠基蒙脱石物化性质的影响及对Cd2+吸附的差异。结果表明:不同前处理方式对钠基蒙脱石比表面积、孔容与层间距等物理性质影响较大,但对表面官能团、阳离子交换量等化学性质影响较小。吸附动力学显示钠基蒙脱石对镉的吸附符合拟二级动力学方程,属离子交换吸附,24 h可达吸附平衡;吸附等温线符合Langmuir等温线方程,属单层吸附。不同方式处理的钠基蒙脱石对于Cd2+吸附效果是有差异的。300℃煅烧处理的钠基蒙脱石吸附效果最好,饱和吸附量达到11.1 mg·g-1;100℃烘干处理的钠基蒙脱石吸附量最差,饱和吸附量为9.1 mg·g-1。 |
英文摘要: |
In this paper, 4 Na-montmorillonites were prepared by 4 pretreatment methods, including oven-drying at 100℃, calcination at 200℃ and 300℃, and freeze-drying. Their physical and chemical properties were investigated. Meanwhile, the adsorption behaviors of the obtained Na-montmorillonites with regard to Cd2+ was discussed. The purpose was to investigate the influence of different pretreatment methods on the physicochemical properties of Na-montmorillonite and its difference in the adsorption of Cd2+. Results showed that the different pretreatment methods had a significant influence on the physical properties, such as the specific surface area, pore volume, and interlayer spacing. However, the effects on chemical properties, such as surface functional groups and cation exchange capacity, were not obvious. The adsorption could achieve equilibrium in 24 hours, while the adsorption kinetics indicated that the quasi-second-order kinetic equation was more suitable for describing the adsorption process, indicating ion-exchange adsorption. The adsorption isotherm was in accordance with the Langmuir isotherm model, partially proving single-layer adsorption. The maximum adsorption capacity of Na-montmorillonite could be achieved by calcination at 300℃, with an adsorption capacity of 11.1 mg·g-1. However, only 9.1 mg·g-1 Cd2+ could be adsorbed, as Na-montmorillonite from the oven-drying treatment at 100℃ was employed. |
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