School of Environmental Science and Engineering, Tianjin University, No. 92, Weijin Rd., Nankai District, Tianjin, 300072, People's Republic of China.
Environ Sci Pollut Res Int. 2016 Feb;23(3):2487-94. doi: 10.1007/s11356-015-5453-z. Epub 2015 Oct 1.
Lanthanum-modified bentonite has potential for wide application in eutrophication control. We investigated P adsorption on a lanthanum-modified bentonite by analysis of adsorption kinetics, equilibrium, and the effect of environmental factors. P adsorption closely followed the pseudo-second-order kinetic model, and the isotherm was well described by the Langmuir model. This adsorbent could effectively immobilize P into the sediment, but the adsorption process was strongly dependent on pH, anions, and low molecular weight organic acids (LMWOAs). P adsorption increased with increasing pH from 0.52 mg P/g at pH 3.0 to 0.93 mg P/g at pH 7.0 with no adsorption at pH 11. P adsorption was strongly inhibited in the presence of anions and three LMWOAs, with P even re-released at high concentrations. These environmental factors should be given significant attention when considering the application of lanthanum-modified bentonite in eutrophication control.
镧改性膨润土在富营养化控制中有广泛的应用潜力。我们通过分析吸附动力学、平衡和环境因素的影响，研究了镧改性膨润土对磷的吸附。磷的吸附很好地遵循了拟二级动力学模型，等温线很好地用朗缪尔模型描述。这种吸附剂可以有效地将磷固定在沉积物中，但吸附过程强烈依赖于 pH 值、阴离子和低分子量有机酸 (LMWOAs)。随着 pH 值从 3.0 时的 0.52mg P/g 增加到 7.0 时的 0.93mg P/g，磷的吸附增加，而在 pH 值为 11 时则没有吸附。在阴离子和三种低分子量有机酸存在的情况下，磷的吸附受到强烈抑制，甚至在高浓度下磷也会重新释放。在考虑将镧改性膨润土应用于富营养化控制时，应高度重视这些环境因素。
