Zhao Min, Zhang Xiao-Ping, Wang Liang-Rong
School of Environment and Energy, South China University of Technology, Guangzhou 510006, China.
Key Laboratory of Pollution Control and Ecosystem Restoration in Industry Clusters of Ministry of Education, Guangzhou 510006, China.
Huan Jing Ke Xue. 2021 Nov 8;42(11):5433-5439. doi: 10.13227/j.hjkx.202103012.
In this work, a novel sodium silicate-modified peanut shell biochar(Si-PSB) was synthesized and used as phosphorus adsorbents. Compared with unmodified biochar(PSB), the adsorption capacity of Si-PSBs increased significantly. The adsorption capacity of 8% sodium silicate solution modified biochar(8%Si-PSB) was 3.9 times higher than that of PSB. The biochar was characterized using scanning electron microscopy(SEM), Fourier transformed infrared(FTIR), and X-ray diffraction(XRD), which confirmed that silica was present on the surface of 8%Si-PSB. The introduction of silica improved the reaction activity of biochar's own metal ions by affecting the morphology of calcium carbonate. The 8%Si-PSB had a good adsorption effect on phosphorus in both acid and alkali environments. Phosphorus adsorption by 8%Si-PSB and PSB was described well by the pseudo-second-order model, and the adsorption capacity after equilibrium fluctuated between 2.79 mg·g and 0.71 mg·g, respectively. Further, the isothermal adsorption experimental data fitted well to the Langmuir model. The presence of humic acid in the solution inhibited the adsorption of phosphorus by the 8%Si-PSB and PSB. The 8%Si-PSB, as a new low-cost phosphorus removal material, can improve the utilization of metal ions in peanut shell itself.
在本研究中，合成了一种新型的硅酸钠改性花生壳生物炭（Si-PSB）并将其用作磷吸附剂。与未改性生物炭（PSB）相比，Si-PSB的吸附容量显著提高。8%硅酸钠溶液改性生物炭（8%Si-PSB）的吸附容量比PSB高3.9倍。通过扫描电子显微镜（SEM）、傅里叶变换红外光谱（FTIR）和X射线衍射（XRD）对生物炭进行了表征，证实8%Si-PSB表面存在二氧化硅。二氧化硅的引入通过影响碳酸钙的形态提高了生物炭自身金属离子的反应活性。8%Si-PSB在酸性和碱性环境中对磷均具有良好的吸附效果。8%Si-PSB和PSB对磷的吸附均能很好地用准二级模型描述，平衡后的吸附容量分别在2.79 mg·g和0.71 mg·g之间波动。此外，等温吸附实验数据与Langmuir模型拟合良好。溶液中腐殖酸的存在抑制了8%Si-PSB和PSB对磷的吸附。8%Si-PSB作为一种新型低成本除磷材料，可提高花生壳本身金属离子的利用率。
