Seagram Center for Soil and Water Sciences, Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 76100, Israel.
J Hazard Mater. 2010 Nov 15;183(1-3):590-5. doi: 10.1016/j.jhazmat.2010.07.065. Epub 2010 Jul 22.
Polymer-clay composites were designed to adsorb selenium from water. The highest adsorption efficiency was obtained for chitosan-montmorillonite composites. These composites were characterized by XRD, zeta potential, and FTIR measurements. Adsorption isotherms of selenate on the composite, on Al-oxide and on Fe-oxide were in good agreement with the Langmuir model, yielding a somewhat higher capacity for the composite, 18.4, 17.2 and 8.2 mg/g, respectively. In addition, adsorption by the composite was not pH dependent while its adsorption by the oxides decreased at high pH. Selenium removal from well water (closed due to high selenium concentrations, 0.1 mg/L) by the composite, brought levels to below the WHO limit (0.01 mg/L) and was selective for selenium even in the presence of sulfur (13 mg/L). Selenium adsorption by the composite was higher than by the Al-oxide due to high adsorption of sulfur by the later. Unlike employment in batch Al-oxide is more suitable for employment in filtration columns due to its high hydraulic conductivity. A semi-pilot columns experiment demonstrated selenium removal from the well water below the recommended limit (first 400 pore volumes) by Al-oxide columns. Regeneration of Al-oxide and of the composite was studied and readsorption of selenium was demonstrated.
聚合物-粘土复合材料被设计用于从水中吸附硒。壳聚糖-蒙脱石复合材料具有最高的吸附效率。这些复合材料通过 XRD、zeta 电位和 FTIR 测量进行了表征。硒酸盐在复合材料、氧化铝和氧化铁上的吸附等温线与朗缪尔模型吻合良好，分别得到了复合材料 18.4、17.2 和 8.2mg/g 的较高吸附容量。此外，复合材料的吸附不受 pH 值影响，而氧化物的吸附则在高 pH 值下降低。通过复合材料将井水（因高硒浓度而关闭，0.1mg/L）中的硒去除到世界卫生组织（WHO）规定的限值（0.01mg/L）以下，并且即使在存在硫（13mg/L）的情况下也具有选择性。由于硫的高吸附性，复合材料对硒的吸附高于氧化铝。与批量使用相比，由于其高水力传导性，氧化铝更适合在过滤柱中使用。半中试柱实验表明，氧化铝柱可将井水（前 400 个孔隙体积）中的硒去除至推荐限值以下。研究了氧化铝和复合材料的再生以及硒的再吸附。
