原位富集铁元素增强生物炭的吸附性能

The enhanced adsorption performance of biochar via in-situ enrichment approach

负载金属型生物炭材料具有良好的吸附性能,但其吸附机制尚有待研究.本文通过香蒲根(Cattail root)原位富集铁(Iron)元素,再经热裂解得到负载铁生物炭(CRI-100)材料.该材料对水中有毒有机染料结晶紫(crystal violet,CV)的吸附效率比空白生物炭(CRI-0)高9.8倍.通过SEM/EDX、XRD和FTIR等表征,结果显示自富集上去的铁以直径约40 nm的Fe_(2)O_(3)纳米颗粒均匀镶嵌在CRI-100表面.实验证明,这种铁纳米颗粒的形成,使CRI-100比表面积(120.84 m^(2)·g^(−1))比未富集铁的生物炭CRI-0(8.05 m^(2)·g^(−1))高15倍,且促使其表面产生了更多羟基位点,用于CV的静电吸附.本研究将为金属富集型植物转化为生物炭吸附剂的后续应用提供理论依据.

Metal-loaded biochar has good adsorption properties,but the understanding of such adsorption remains limited.In this study,the iron-loading biochar(CRI-100)were prepared through in-situ enrichment on cattail root and then pyrolysis.CRI-100 exhibited the adsorption efficiency of Crystal Violet(CV),a toxic organic dye in water,was 9.8 times higher than that of the blank biochar(CRI-0).On the basis of SEM/EDX,XRD and FTIR characterizations,the self-enriched iron exists in the form of Fe_(2)O_(3) nanoparticles with a diameter of about 40 nm,which were evenly embedded on the surface of CRI-100.The presence of these nanoparticles rendered the specific surface area(120.84 m^(2)·g^(−1))of CRI-100 was 15 times higher than that of CRI-0 without iron(8.05 m^(2)·g^(−1)),and increased the amount of surface hydroxyl sites that were applied to the electrostatic adsorption of CV.This study will provide a theoretical basis for the subsequent applications of metal-enriched plants into biochar adsorbents.