Enhanced cementation of Cd2+, Co2+, Ni2+, and Zn2+ on Al from sulfate solutions by activated carbon addition
Enhanced cementation of Cd2+, Co2+, Ni2+, and Zn2+ on Al from sulfate solutions by activated carbon addition
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DOI：
10.1016/j.hydromet.2021.105580
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发表时间：
2021-03-02
期刊：
影响因子：
4.7
通讯作者：
Hiroyoshi, Naoki
中科院分区：
文献类型：
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作者：
Choi, Sanghyeon;Jeon, Sanghee;Hiroyoshi, Naoki
镉 (Cd)、钴 (Co)、镍 (Ni) 和锌 (Zn) 是电池和可再生能源技术的重要组成部分，但从浸出液中回收或从受污染的土壤系统和水体中去除它们仍然具有挑战性。在这项研究中，我们报告了通过使用铝 (Al) 和活性炭 (AC) 的新型胶结技术（称为“AC/Al 胶结”）从硫酸盐溶液中去除/回收重金属离子（Cd2+、Co2+、Ni2+ 和 Zn2+）。结果显示，仅使用 Al 对四种重金属的去除/回收效率与 0% 类似，但通过“AC/Al 胶结”，Zn2+、Ni2+、Co2+ 和 Cd2+ 的这些值分别增加到 96%、61%、57% 和 45%。使用 SEM-EDX、XPS 和 AES 进行的详细残留物表征显示，重金属离子以其元素形式大量沉积，表明去除/回收的主要机制是胶结。此外，结果还确定了 AC 作为从 Al（电子供体）到金属离子（电子受体）的电子路径的关键作用，即使 Al 被 Al2O3 覆盖。最后，氢超电势和随后的Al(OH)(3)对胶结重金属的钝化是影响“AC/Al胶结”技术效率的重要限制因素和过程。
Cadmium (Cd), cobalt (Co), nickel (Ni), and zinc (Zn) are important components of batteries and renewable energy technologies but their recovery from pregnant leach solutions or removal from polluted soil systems and water bodies remain challenging. In this study, we report the removal/recovery of heavy metal ions (Cd2+, Co2+ and Ni2+, and Zn2+) from sulfate solutions by a novel cementation technique using aluminum (Al) and activated carbon (AC) called "AC/Al-cementation". The results showed similar to 0% removal/recovery efficiencies with Al only for the four heavy metals but with "AC/Al-cementation", these values increased to 96%, 61%, 57%, and 45% for Zn2+, Ni2+, Co2+, and Cd2+, respectively. Detailed residue characterizations using SEM-EDX, XPS, and AES showed substantial deposition of heavy metal ions in their elemental forms, indicating that the primary mechanism of removal/recovery was cementation. Moreover, the results identified the critical role of AC as an electron pathway from Al (electron donor) to metal ions (electron acceptors) even though Al was covered with Al2O3. Finally, hydrogen overpotential and the subsequent passivation of cemented heavy metals by Al(OH)(3) were important limiting factors and processes affecting the efficiency of "AC/Al-cementation" technique.