School of Resources & Environment and Safety Engineering, University of South China, Hengyang, Hunan, 421001, China; Hunan Province Engineering Research Centre of Radioactive Control Technology in Uranium Mining and Metallurgy, Hengyang, Hunan, 421001, China; Hengyang Key Laboratory of Soil Pollution Control and Remediation, University of South China, Hengyang, 421001, China.
School of Resources & Environment and Safety Engineering, University of South China, Hengyang, Hunan, 421001, China.
Environ Pollut. 2020 Jul;262:114184. doi: 10.1016/j.envpol.2020.114184. Epub 2020 Feb 28.
Goethite is a common iron hydroxide, which can be substituted by manganese (Mn) in the goethite structure. It is important to investigate the immobilization of uranium(VI) on Mn-substituted goethite (Mn-Goe) to understand the fate and migration of uranium in soils and sediments. In this study, the sorption of uranium(VI) by Mn-Goe was investigated as a function of pH, adsorbent dosage, contact time, and initial uranium concentration in batch experiments. Several material analysis techniques were used to characterize manganese substituted materials. Results indicated that Mn was successfully introduced into the goethite structure, the length of particles increased gradually, the surface clearly exhibited higher roughness with increasing Mn content, and that uranium(VI) sorption of synthetic Mn-Goe appeared to be higher than that of goethite. The sorption kinetics supported the results presented by the pseudo-second-order model. The sorption capacity of uranium on Mn-Goe was circa 77 mg g at pH = 4.0 and 25 °C. Fourier transform-infrared spectroscopy (FT-IR) analyses revealed that uranium ions were adsorbed through functional groups containing oxygen on the Mn-Goe structure. The enhancement of Mn-substitution for the uranium(VI) sorption capacity of goethite was revealed. This study suggests that goethite and Mn-Goe can both play a significant role in controlling the mobility and transport of uranium(VI) in the subsurface environment, which is helpful for material development in environmental remediation.
针铁矿是一种常见的氢氧化铁，其结构中可以被锰（Mn）取代。研究铀（VI）在 Mn 取代针铁矿（Mn-Goe）上的固定，对于了解铀在土壤和沉积物中的赋存和迁移非常重要。在这项研究中，通过批量实验研究了 pH 值、吸附剂用量、接触时间和初始铀浓度对 Mn-Goe 吸附铀（VI）的影响。采用了几种材料分析技术对 Mn 取代材料进行了表征。结果表明，Mn 成功地引入了针铁矿结构，颗粒长度逐渐增加，表面明显表现出随着 Mn 含量的增加而增加的粗糙度，并且合成的 Mn-Goe 对铀（VI）的吸附似乎高于针铁矿。吸附动力学支持准二级模型的结果。在 pH = 4.0 和 25°C 时，Mn-Goe 对铀的吸附容量约为 77 mg g。傅里叶变换红外光谱（FT-IR）分析表明，铀离子通过 Mn-Goe 结构上含氧的官能团被吸附。揭示了 Mn 取代增强了针铁矿对铀（VI）的吸附能力。本研究表明，针铁矿和 Mn-Goe 都可以在控制铀（VI）在地下环境中的迁移和传输方面发挥重要作用，这有助于环境修复中材料的开发。
