Department of Environment and Energy, Sejong University, Seoul, 05006, Republic of Korea.
Geologic Environment Division, Korea Institute of Geoscience and Mineral Resources (KIGAM), Daejeon, 34132, Republic of Korea.
Environ Res. 2020 Sep;188:109809. doi: 10.1016/j.envres.2020.109809. Epub 2020 Jun 14.
This study aimed to compare the adsorption performance of Fe-biochar composites (Fe-C-N and Fe-C-CO), fabricated by co-pyrolysis of red mud and orange peel in N and CO, for As(V) and Ni(II). By the syngas production comparison test, it was confirmed that CO was more advantageous than N as a pyrolytic medium gas to produce more CO. The resulting Fe-biochar composite showed the aggregate morphology consisting of different Fe phases (magnetite or metal Fe) from the inherent hematite phase in red mud and carbonized carbon matrix, and there was no distinct difference between the structural shapes of two Fe-biochar composites. Adsorption experiments showed that the adsorption capacities for As(V) and Ni(II) in single mode were almost similar with 7.5 and 16.2 mg g for Fe-C-N and 5.6 and 15.1 mg g for Fe-C-CO, respectively. The adsorption ability of Fe-C-CO for both As(V) and Ni(II) was further enhanced in binary adsorption mode (As(V): 13.4 mg g, Ni(II):17.6 mg g) through additional removal of those ions by Ni(II)-As(V) complexation. The overall results demonstrated CO-assisted pyrolysis can provide a viable platform to convert waste materials into fuel gases and environmental media for co-adsorption of cationic and anionic heavy metals.
本研究旨在比较通过红泥和橙皮在 N 和 CO 中共热解制备的 Fe-生物炭复合材料（Fe-C-N 和 Fe-C-CO）对 As(V)和 Ni(II)的吸附性能。通过合成气生产比较测试，证实 CO 作为热解介质气体比 N 更有利，可产生更多的 CO。所得 Fe-生物炭复合材料呈现出不同 Fe 相（磁铁矿或金属 Fe）的聚集体形态，与红泥中固有的赤铁矿相和碳化碳基质不同，两种 Fe-生物炭复合材料的结构形状没有明显区别。吸附实验表明，两种模式下对 As(V)和 Ni(II)的吸附容量几乎相同，Fe-C-N 分别为 7.5 和 16.2 mg/g，Fe-C-CO 分别为 5.6 和 15.1 mg/g。在二元吸附模式下（As(V)：13.4 mg/g，Ni(II)：17.6 mg/g），Fe-C-CO 对 As(V)和 Ni(II)的吸附能力进一步增强，通过 Ni(II)-As(V)络合进一步去除这些离子。总体结果表明，CO 辅助热解可以为废物转化为燃料气体和环境介质提供可行的平台，用于阳离子和阴离子重金属的共吸附。
