Department of Chemistry, Purushottam Institute of Engineering & Technology, Rourkela 770034, Orissa, India.
J Environ Manage. 2010 Sep;91(9):1883-91. doi: 10.1016/j.jenvman.2010.04.013. Epub 2010 May 23.
A laboratory study was conducted to investigate the efficiency of hydroxyapatite (HAP) towards removal of nitrate from synthetic nitrate solution. In the present research HAP synthesized from egg-shell was characterized using SEM, XRD, FTIR and TGA-DSC. The removal of nitrate was 96% under neutral conditions, using 0.3 g of adsorbent in 100 mL of nitrate solution having an initial concentration of 100 mg/L. An adsorption kinetic study revealed that the adsorption process followed first order kinetics. Adsorption data were fitted to a linearly transformed Langmuir isotherm with correlation coefficient (R(2))>0.98. 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 the Dubinin-Radushkevich isotherm. The process was rapid and equilibrium was established within the first 40 min.
一项实验室研究旨在探究羟基磷灰石（HAP）对硝态氮的去除效率，研究对象为人工合成的硝态氮溶液。本研究采用 SEM、XRD、FTIR 和 TGA-DSC 对蛋壳合成的 HAP 进行了表征。在中性条件下，使用 0.3 g 吸附剂处理 100 mL 初始浓度为 100 mg/L 的硝态氮溶液，去除率达到 96%。吸附动力学研究表明，吸附过程遵循一级动力学。吸附数据符合线性转化的 Langmuir 等温线，相关系数（R(2)）>0.98。还计算了热力学参数以研究温度对去除过程的影响。为了了解吸附类型，使用 Dubinin-Radushkevich 等温线对平衡数据进行了测试。该过程迅速，在前 40 分钟内达到平衡。
