The tannic acid-chitosan hydrothermal carbon (TCHC) by hydrothermal carbonization is first used in uranium(VI) adsorption. The characterization of HCTC was investigated by scanning electron microscopy, X-ray diffraction, infrared spectroscopy (FTIR). The effects of pH, adsorbent dosage, initial U(VI) concentration, temperature and contact time on the adsorption of uranium(VI) were expressed in batch experiments. A maximum adsorption capacity 96.99 mg/g has been achieved at pH = 5.5, T = 25 °C and initial concentration of U(VI) solution 80 mg/L. The adsorption data fit well with the Langmuir model and pseudo second order kinetics model, indicating that uranium(VI) was monolayer covered on the surface of the material, and the adsorption process was mainly chemisorption. Thermodynamic data indicates that the immobilization of uranium(VI) to the material surface was spontaneous and endothermic. TCHC in low-cost is a promising adsorbent for uranium(VI) adsorption.

中文翻译：

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单宁酸-壳聚糖热液碳从水介质中去除铀酰离子：平衡、动力学和热力学

通过水热碳化的单宁酸-壳聚糖水热碳（TCHC）首先用于铀（VI）吸附。通过扫描电子显微镜、X 射线衍射、红外光谱 (FTIR) 研究了 HCTC 的表征。pH值、吸附剂用量、初始U(VI)浓度、温度和接触时间对铀(VI)吸附的影响在批量实验中得到表达。在 pH = 5.5、T = 25 °C 和 U(VI) 溶液的初始浓度为 80 mg/L 时，已实现了 96.99 mg/g 的最大吸附容量。吸附数据与Langmuir模型和准二级动力学模型拟合良好，表明铀(VI)单层覆盖在材料表面，吸附过程以化学吸附为主。热力学数据表明铀（VI）在材料表面的固定是自发和吸热的。低成本的 TCHC 是一种很有前途的铀 (VI) 吸附剂。