Adsorption of inorganic and organic arsenic from aqueous solutions by polymeric Al/Fe modified montmorillonite
Adsorption of inorganic and organic arsenic from aqueous solutions by polymeric Al/Fe modified montmorillonite
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DOI：
10.1016/j.seppur.2007.01.025
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发表时间：
2007-08-01
影响因子：
8.6
通讯作者：
Ueda, K.
中科院分区：
文献类型：
--
作者：
Ramesh, A.;Hasegawa, H.;Ueda, K.
研究了聚合物Al/Fe改性蒙脱土对水溶液中亚砷酸盐[As(III)]、亚砷酸盐[As(V)]和二甲基砷酸盐(DMA)的吸附。研究了吸附时间、pH值、吸附剂投加量和金属初始浓度对As(III)、As(V)和DMA吸附的影响。采用傅立叶变换红外光谱(FT-IR)和扫描电子显微镜(SEM)分别对蒙脱土和聚合Al/Fe改性蒙脱土的官能团和表面形貌进行了分析。扫描电子显微镜照片表明，聚合物Al/Fe物种的改性减小了粘土颗粒的尺寸和聚集性。结果表明，在As(V)、As(III)和DMA的pH值分别为3.0~6.0、7.0~9.0和3.0~7.0的范围内，聚合物Al/Fe改性蒙脱石的吸附性能最好。用Freundlich和Langmuir吸附等温线模型对吸附数据进行了分析，Freundlich等温线模型对数据进行了较好的拟合。动力学数据符合准二级动力学模型，表明吸附过程可能为化学吸附。热力学研究表明，吸附过程本质上是吸热自发的。磷和铁的存在降低了砷的吸附效率，而其他常见共存离子对砷的吸附没有显著影响。用稀氯化钠溶液进行了解吸研究。(C)2007 Elsevier B.V.保留所有权利。
Adsorption of arsenite [As(III)], arsenate [As(V)] and dimethylarsinate (DMA) from aqueous solutions onto polymeric Al/Fe modified montmorillonite was studied. Batch adsorption studies were carried out on the adsorption of As(III), As(V) and DMA as a function of contact time, pH, adsorbent dose and initial metal concentration. Fourier transform infrared spectrometry (FT-IR) and scanning electron microscopy (SEM) were used to analyze the functional groups and surface morphology of the montmorillonite or polymeric Al/Fe modified montmorillonite, respectively. SEM images show that modification with polymeric Al/Fe species reduces the clay particle size and aggregation. The results indicate that the maximum adsorption of polymeric Al/Fe modified montmorillonite was obtained in the pH range 3.0-6.0 for As(V), 7.0-9.0 for As(III) and 3.0-7.0 for DMA. The adsorption data was analyzed by both Freundlich and Langmuir isotherm models and the data was well fit by the Freundlich isotherm model. Kinetic data correlated well with the pseudo-second-order kinetic model, suggesting that the adsorption process might be chemical sorption. Thermodynamic studies showed that the adsorption process was endothermic and spontaneous in nature. The presence of phosphate and iron reduced the adsorption efficiency of arsenic, whereas other common coexisting ions had no significant effect on arsenic adsorption. The desorption studies were carried out using dilute NaCl solution. (c) 2007 Elsevier B.V. All rights reserved.