Department of Power Engineering, North China Electric Power University, Yonghua North Street 619, Baoding, 071003, People's Republic of China.
Environ Sci Pollut Res Int. 2018 Feb;25(5):4320-4329. doi: 10.1007/s11356-017-0778-4. Epub 2017 Nov 27.
The adsorption of [Formula: see text] and [Formula: see text] by sesame straw biochars (C-300, C-500, and C-700) prepared under different temperatures (300, 500, and 700 °C) was investigated in this study. The physicochemical properties of the biochars were characterized using Brunauer-Emmett-Teller method, X-ray diffraction, scanning electron microscopy, and Fourier transform infrared spectrometry. In batch experiments, C-300 showed the best [Formula: see text] adsorption capacity of 3.45 mg/g because of its abundant surface functional groups at low pyrolysis temperature. C-700 achieved the optimal [Formula: see text] adsorption capacity of 34.17 mg/g because of its high Ca, Mg, and Al contents and high surface area at high pyrolysis temperature. The isothermal study showed that the Langmuir-Freundlich model could sufficiently describe the [Formula: see text] and [Formula: see text] adsorption values, indicating the multiple adsorption processes of nutrients on biochars. The maximum [Formula: see text] adsorption capacity was 93.61 mg/g on C-300, whereas the maximum [Formula: see text] adsorption capacity was as high as 116.58 mg/g on C-700. Kinetic study showed that [Formula: see text] adsorption on C-300 was mainly controlled by intraparticle diffusion, and the pseudo-second-order model could well describe [Formula: see text] adsorption on C-700.
本研究考察了在不同温度（300、500 和 700°C）下制备的芝麻秸秆生物炭（C-300、C-500 和 C-700）对[Formula: see text]和[Formula: see text]的吸附。采用比表面积仪、X 射线衍射仪、扫描电子显微镜和傅里叶变换红外光谱仪对生物炭的理化性质进行了表征。在批实验中，C-300 由于在较低的热解温度下具有丰富的表面官能团，表现出最佳的[Formula: see text]吸附能力为 3.45mg/g。C-700 由于在较高的热解温度下具有较高的 Ca、Mg 和 Al 含量和较大的比表面积，实现了最佳的[Formula: see text]吸附容量 34.17mg/g。等温研究表明，Langmuir-Freundlich 模型能够充分描述[Formula: see text]和[Formula: see text]的吸附值，表明养分在生物炭上的多步吸附过程。C-300 对[Formula: see text]的最大吸附容量为 93.61mg/g，而 C-700 对[Formula: see text]的最大吸附容量高达 116.58mg/g。动力学研究表明，C-300 上的[Formula: see text]吸附主要受颗粒内扩散控制，准二级模型能够很好地描述 C-700 上的[Formula: see text]吸附。
