Islam Mahamudur, Patel Rajkishore
Department of Chemistry, Purushottam Institute of Engineering and Technology, Rourkela 77 0 034, India.
J Hazard Mater. 2009 Sep 30;169(1-3):524-31. doi: 10.1016/j.jhazmat.2009.03.128. Epub 2009 Apr 5.
A laboratory study was conducted to investigate the ability of Mg-Al-Cl hydrotalcite-like compound for the removal of nitrate from synthetic nitrate solution. In the present study Mg-Al-Cl hydrotalcite was synthesized by co-precipitation method and was characterized using SEM, XRD, FTIR and TGA-DSC. To know the practical applicability, a detailed removal study of nitrate ion was carried out. The removal of nitrate was 87.6% under neutral condition, using 0.3g of adsorbent in 100mL of nitrate solution having initial concentration of 10mg/L. Adsorption kinetic study revealed that the adsorption process followed first-order kinetics. Adsorption data were fitted to linearly transformed Langmuir isotherm with R(2) (correlation coefficient)>0.99. Thermodynamic parameters were also calculated to study the effect of temperature on the removal process. In order to understand the adsorption type, equilibrium data were tested with Dubinin-Radushkevich isotherm. The percentage removal was found to decrease gradually with increase in pH and the optimum pH was found to be 6. The process was rapid and equilibrium was established within first 40 min.
进行了一项实验室研究，以考察镁铝氯类水滑石化合物从合成硝酸盐溶液中去除硝酸盐的能力。在本研究中，采用共沉淀法合成了镁铝氯水滑石，并通过扫描电子显微镜（SEM）、X射线衍射（XRD）、傅里叶变换红外光谱（FTIR）和热重-差示扫描量热法（TGA-DSC）对其进行了表征。为了解其实际适用性，对硝酸根离子进行了详细的去除研究。在中性条件下，使用0.3g吸附剂处理100mL初始浓度为10mg/L的硝酸盐溶液，硝酸盐的去除率为87.6%。吸附动力学研究表明，吸附过程遵循一级动力学。吸附数据拟合线性变换的朗缪尔等温线，相关系数R²>0.99。还计算了热力学参数，以研究温度对去除过程的影响。为了解吸附类型，用杜比宁-拉杜什凯维奇等温线对平衡数据进行了测试。发现去除率随pH值升高而逐渐降低，最佳pH值为6。该过程迅速，在前40分钟内达到平衡。
