类水滑石复合材料吸附去除水中硫酸根离子

Removal of Sulfate Ions from Aqueous Solution by Adsorption with Hydrotalcitelike Composite

用共沉淀法制备的类水滑石复合材料作为吸附剂去除水中的硫酸根离子.利用XRD、FT-IR、SEM和EDS元素分析对类水滑石复合材料的结构和组成进行了分析.研究了时间、p H值和共存离子对吸附量的影响.结果表明,类水滑石复合材料是锌铝硝酸根类水滑石和锌铝苯丙氨酸类水滑石的复合材料;类水滑石复合材料对硫酸根离子具有良好的吸附性能,最大吸附量可达到52.75 mg·g^(-1);准二级动力学模型对数据的拟合效果最好,说明吸附速率是由化学吸附控制的;吸附过程更符合Freundlich吸附等温模型,说明类水滑石复合材料对硫酸根离子的吸附是多层吸附;热力学参数表明在常温下吸附过程是自发的吸热过程;类水滑石复合材料吸附硫酸根离子主要是通过离子交换、静电引力作用以及物理吸附的途径来实现的.实验结果表明,该类水滑石复合材料是一种潜在的去除水中硫酸根离子的吸附剂.

Hydrotalcite-like composite synthesized by co-precipitation method was used as an adsorbent to remove the sulfate ions in aqueous solution. XRD,FT-IR,SEM and EDS elemental analysis were used to clarify the structure and composition of the hydrotalcitelike composite. The influences of time,initial p H value and coexisting ions on adsorption performance were investigated. The result showed the material was the composite of zinc aluminum nitrate hydrotalcite-like compounds and zinc aluminum phenylalanine hydrotalcite-like compounds. Hydrotalcite-like composite had a good performance in adsorption of sulfate ions,and the maximum adsorption capacity was 52. 75 mg·g^（-1）. The data fitted pseudo-second order kinetic model best,which indicated that chemical adsorption was the rate-limiting step. Freundlich isotherm was more suitable to describe the adsorption process,and this meant the adsorption of sulfate ions by hydrotalcite-like composite was multilayered adsorption. Thermodynamic parameters showed that the adsorption process was endothermic and spontaneous at room temperature. Hydrotalcite-like composite adsorbed sulfate ions mainly through ion exchange,electrostatic force and physical adsorption. The experimental results showed that the hydrotalcite-like composite had potential for sulfate ion removal in the aqueous solution.