School of Water Resources and Environment, China University of Geosciences (Beijing), Beijing, 100083, China.
Key Laboratory of Groundwater Cycle and Environment Evolution (China University of Geosciences (Beijing)), Ministry of Education, Beijing, 100083, China.
Environ Sci Pollut Res Int. 2018 Jun;25(16):15326-15335. doi: 10.1007/s11356-018-1727-6. Epub 2018 Mar 21.
To obtain an economical and effective adsorbent for fluoride removal, lanthanum-loaded pomelo peel biochar (PPBC-La) was synthesized using a facile approach. The batch adsorption experiments were investigated to determine adsorbent performance. The PPBC-La and its pristine biochar (PPBC) were characterized by scanning electronic microscopy (SEM), zeta potential, Brunauer-Emmett-Teller (BET), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) methods. Experimental results showed that the adsorption data were described well by the pseudo-second-order kinetic and Freundlich isotherm models. The maximum fluoride adsorption capacity for PPBC-La was found to be 19.86 mg/g at 25 °C and pH 6.5. The PPBC-La worked well at pH 2.4-9.6 and carried positive charge at pH < 5.8. The presence of SO, Cl, and NO had a slight effect on fluoride uptake except HCO and PO. The real groundwater study testified that 9.8 mg/L of fluoride was removed effectively at 1.0 g/L of dosage and pH 5.2. The regeneration results revealed that the PPBC-La had a good reusability. According to FTIR, XPS analysis and the anion exchange experiment, anions (NO and OH) exchange with fluoride ions was mainly responsible for fluoride adsorption.
为了获得一种经济有效的除氟吸附剂，采用简便的方法合成了负载镧的柚子皮生物炭（PPBC-La）。通过批量吸附实验研究了吸附剂的性能。采用扫描电子显微镜（SEM）、zeta 电位、Brunauer-Emmett-Teller（BET）、傅里叶变换红外光谱（FTIR）和 X 射线光电子能谱（XPS）方法对 PPBC-La 及其原始生物炭（PPBC）进行了表征。实验结果表明，吸附数据很好地符合准二级动力学和 Freundlich 等温线模型。在 25°C 和 pH 6.5 下，PPBC-La 的最大氟吸附容量为 19.86 mg/g。PPBC-La 在 pH 2.4-9.6 范围内效果良好，在 pH < 5.8 时带正电荷。除 HCO 和 PO 外，SO、Cl 和 NO 的存在对氟的吸收影响很小。实际地下水研究证明，在 1.0 g/L 剂量和 pH 5.2 下，可有效去除 9.8 mg/L 的氟。再生结果表明，PPBC-La 具有良好的可重复使用性。根据 FTIR、XPS 分析和阴离子交换实验，阴离子（NO 和 OH）与氟离子的交换主要负责氟的吸附。
