La3+/La(OH)3 loaded magnetic cationic hydrogel composites for phosphate removal: Effect of lanthanum species and mechanistic study
La3+/La(OH)3 loaded magnetic cationic hydrogel composites for phosphate removal: Effect of lanthanum species and mechanistic study
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La3 /La(OH)(3)负载磁性阳离子水凝胶复合材料用于除磷：镧种类的影响和机理研究
DOI：
10.1016/j.watres.2017.09.050
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发表时间：
2017-12-01
期刊：
影响因子：
12.8
通讯作者：
Zheng, Huaili
中科院分区：
文献类型：
--
作者：
Dong, Shuoxun;Wang, Yili;Zheng, Huaili
本研究原位制备了La 3+（ion）/La（OH）（3）-W/La（OH）（3）-EW磁性阳离子水凝胶（MCH）复合材料，并对其进行了表征，研究了镧离子对MCH吸附磷酸盐的影响。MCH负载的La 3+（ion）（MCHLa 3+（ion））、La（OH）（3）-W（MCH-La（OH）（3）-W）和La（OH）（3）-EW（MCH-La（OH）（3）-EW）的相应最大P吸附容量分别为70.5 +/- 2.67、69.2 +/- 3.5和90.2 +/- 2.9 mg P/g。在pH 4.5 ~ 11范围内，由于配体交换、静电作用和刘易斯酸碱作用，MCH-La（OH）（3）-EW对磷的吸附量相对稳定，且吸附量较高。在较宽的pH范围内，以及在竞争阴离子（包括Cl-、NO3-、SO 42-、HCO 3-和SiO 44-）存在下，均能实现对P的增强吸附。用NaOH-NaCl脱附剂可以很容易地将脱附后的MCH-La（OH）（3）-EW再生，在5次循环中仍保持72%以上的吸附量。当磷浓度从5 mg/L降至0.1mg/L时，MCH-La（OH）3-EW柱吸附容量可达3500床体积（BV）（相当于67.7mg P/g）。拉曼和XPS解卷积结果表明，MCH和La（OH）（3）-W和La（OH）（3）-EW对磷酸根的吸附都有贡献，这是由于-N+（CH 3）（3）与磷酸根之间的静电相互作用以及LaPO 4中心点xH（2）O的形成。(C)2017爱思唯尔有限公司版权所有
In this study, La3+(ion)/La(OH)(3)-W/La(OH)(3)-EW-loaded magnetic cationic hydrogel (MCH) composites were fabricated in situ and characterized to investigate the effects of lanthanum species on phosphate adsorption. The corresponding maximum P adsorption capacities of MCH-loaded La3+(ion) (MCHLa3+(ion)), La(OH)(3)-W (MCH-La(OH)(3)-W), and La(OH)(3)-EW (MCH-La(OH)(3)-EW) were 70.5 +/- 2.67, 69.2 +/- 3.5, and 90.2 +/- 2.9 mg P/g, respectively. Furthermore, for MCH-La(OH)(3)-EW, the P adsorption capacity was maintained relatively stable and high at pH 4.5-11 because of the ligand exchange, electrostatic interactions, and Lewis acid base interactions. The enhanced adsorption of P was achieved over a wide pH range, as well as in the presence of competing anions (including Cl-, NO3-, SO42- , HCO3- and SiO44-). Moreover, the exhausted MCH-La(OH)(3)-EW could be easily regenerated by a NaOH-NaCI desorption agent with above 72% adsorption capacity remained during five recycles. The column adsorption capacity of MCH-La(OH)(3)-EW reached 3500 bed volumes (BV) (similar to 67.7 mg P/g) as the concentration of P decreased from 5 mg/L to 0.1 mg/L. The Raman, and XPS deconvolution results revealed that both MCH and lanthanum compounds, including La3+(ion), La(OH)(3)-W and La(OH)(3)-EW, contributed to the phosphate adsorption because of the electrostatic interactions between -N+(CH3)(3) and phosphate, as well as the formation of LaPO4 center dot xH(2)O. (C) 2017 Elsevier Ltd. All rights reserved.