Laboratory of Materials Technology, University of Science and Technology Houari Boumediene, BP 32, 16123, El-Alia, Bab-Ezzouar, Algiers, Algeria E-mail:
Atomic Energy Commission, Nuclear Research Center of Draria, BP 43, 16050 Draria, Algiers, Algeria.
Water Sci Technol. 2021 Mar;83(5):1198-1216. doi: 10.2166/wst.2021.022.
Hydroxyapatite (HAp) was synthesized from biowaste hen eggshells by wet precipitation method in which calcium hydroxide and phosphoric acid were used as precursors. The effectiveness of uranium(VI) adsorption onto HAp was investigated by batch adsorption experiments from aqueous solutions. The obtained HAp powder was characterized by X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectrometry, point of zero charge and Scanning electron microscope. The factors and levels used during the experiments were pH (2-5), adsorbent mass (0.01-0.05 g), and initial U(VI) concentration (100-310 mg L). A Box-Behnken design combined with analysis of variance was used to interpret the main effect influencing the adsorption. The results showed that pH was the most significant parameter affecting U(VI). The kinetic data correlates well with the pseudo-second-order model. The adsorption isotherms fitted the Langmuir-1 type model with the q = 175.22 mg g at 25 °C. The calculated value of the mean free energy indicates the chemisorption process. Under optimal conditions, the uranium effluent derived from the precipitation of ammonium uranyl carbonate removal performance of 98% was achieved. This study proved that HAp prepared from eggshell was an ecofriendly and low-cost adsorbent and was very effective for the adsorption of U(VI) from aqueous solutions.
羟基磷灰石（HAp）是由生物废弃物鸡蛋壳通过湿法沉淀法合成的，其中使用氢氧化钙和磷酸作为前体。通过批处理吸附实验，研究了铀（VI）在 HAp 上的吸附效果。通过 X 射线衍射、傅里叶变换红外光谱、拉曼光谱、等电点和扫描电子显微镜对所得 HAp 粉末进行了表征。实验中使用的因素和水平为 pH（2-5）、吸附剂质量（0.01-0.05 g）和初始 U（VI）浓度（100-310 mg/L）。采用 Box-Behnken 设计和方差分析来解释影响吸附的主要因素。结果表明，pH 是影响 U（VI）吸附的最显著参数。动力学数据与拟二级模型很好地相关。吸附等温线符合 Langmuir-1 型模型，在 25°C 时 q 值为 175.22 mg/g。平均自由能的计算值表明该吸附过程为化学吸附。在最佳条件下，实现了由碳酸铀酰铵沉淀去除铀的出水中铀的去除率达到 98%。本研究证明了蛋壳制备的 HAp 是一种环保且低成本的吸附剂，对于从水溶液中吸附 U（VI）非常有效。
