Tungstate adsorption onto oxisols in the vicinity of the world's largest and longest-operating tungsten mine in China
Tungstate adsorption onto oxisols in the vicinity of the world's largest and longest-operating tungsten mine in China
复制标题
中国世界最大、运行时间最长的钨矿附近氧化土中钨酸盐的吸附
DOI：
10.1039/c4ra09940k
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发表时间：
2014-11
期刊：
影响因子：
3.9
通讯作者：
B.B. Guo
中科院分区：
文献类型：
--
作者：
R.P. Lin;R.N. Luan;C.Y. Lin;B.B. Guo
钨酸盐在土壤中的吸附对于了解钨酸盐的流动性和生物有效性至关重要，但这方面的研究还很缺乏。本研究的目的是研究钨酸盐吸附到oxisol样品在世界上最大的和最长的经营在中国的钨矿附近的动力学和等温线。此外，还研究了pH、离子强度和磷酸根离子对土壤吸附钨酸根的影响。结果表明，钨酸盐吸附动力学符合准二级动力学模型。微孔（颗粒内）扩散和超微孔（粘土内）扩散通常是吸附限制机制。钨酸盐吸附等温线符合Langmuir和Freundlich模型。羟甲醚样品的最大吸附容量为10.67 mmol kg−1，而分配系数为12.60（mmol kg−1）（mol L−1）−1/n。当pH从4.93增加到5.23时，钨酸盐的吸附率从96.1%下降到90.2%，而当离子强度从0.01 M增加到0.1 M NaCl时，钨酸盐的吸附率从90.1%增加到95.5%。随着磷酸盐浓度从0.008 mM增加到0.215 mM，钨酸盐吸附量从2.32 mmol kg−1略微降低到1.97 mmol kg−1。这些结果表明，钨酸根可能主要通过内球络合作用吸附到土壤矿物的钨酸根专属性吸附位上。尽管土壤中钨含量很高（例如21.9 mg kg−1），但它仍然具有很高的钨酸盐吸附能力。
Tungstate adsorption in soils is critical to understand tungstate mobility and bioavailability, but study of this is lacking. The objectives of this study are to investigate the kinetics and isotherms of tungstate adsorption onto oxisol samples in the vicinity of the world's largest and longest-operating tungsten mine in China. In addition, the effects of pH, ionic strength, and phosphate anion on tungstate adsorption onto the soil were studied. Results show that the tungstate adsorption kinetics is fitted best by a pseudo-second order model. Micropore (intraparticle) diffusion and ultramicropore (within clays) diffusion are generally the adsorption-limiting mechanisms. Tungstate adsorption isotherms are fitted well by both Langmuir and Freundlich models. The maximal adsorption capacity of the oxisol sample is 10.67 mmol kg−1, while the distribution coefficient is 12.60 (mmol kg−1) (mol L−1)−1/n. Tungstate adsorption decreased from 96.1% to 90.2% with the pH increase from 4.93 to 5.23, while it increased from 90.1% to 95.5% with the increase of ionic strength from 0.01 M to 0.1 M NaCl. With the increase of phosphate concentration from 0.008 mM to 0.215 mM, tungstate adsorption slightly decreased from 2.32 mmol kg−1 to 1.97 mmol kg−1. These results demonstrate that tungstate might be adsorbed onto the tungstate-specific adsorption sites of the soil minerals mainly via inner-sphere complexation. Despite the soil containing a high tungsten content (e.g. 21.9 mg kg−1), it still has a high tungstate adsorption capacity.
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影响因子：
9.8
作者：
M. Benarie
通讯作者：
M. Benarie
影响因子：
15
作者：
BOYD, GE;ADAMSON, AW;MYERS, LS
通讯作者：
MYERS, LS
影响因子：
10.4
作者：
Steinmaus C;Lu M;Todd RL;Smith AH
通讯作者：
Smith AH
影响因子：
1.8
作者：
Dermatas, D;Braida, W;Larson, S
通讯作者：
Larson, S
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8.8
作者：
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通讯作者：
N. Xu;C. Christodoulatos;W. Braida