Abstract：
Fluoride levels greater than 1.5 mg/L in drinking water are a global environmental issue that can seriously harm the health of humans. One of the most effective techniques for defluoridating water is adsorption. The main drawbacks of many adsorbent materials include their poor adsorption capabilities, prolonged contact times, excessively low or high pH levels, and high dosages. The biochar-based magnetic nanocomposite adsorbent was synthesized in the current study and used as an adsorbent for water defluoridation. Through slow pyrolysis, coffee husk waste was converted to biochar. The composite was created by chemically co-precipitating iron and lanthanum oxide nanoparticles onto the surface of biochar. By using X-ray diffraction analysis (XRD), Fourier transform infrared spectrometry (FTIR), Brunauer-Emmett-Teller (BET), and pHPZC values, researchers were able to describe the magnetic biochar nanocomposite material. The Central Composite Design (CCD), which uses four input variables including dosage (2-5 g/L), solution pH (4-8), contact time (30-70 min), and initial concentration (10-20 mg/L), was used to design the experiments. The quadratic model indicated that the ideal conditions for removing 98.994% of the fluoride from water (adsorbent dosage of 5 g L-1, pH 5.74, contact period of 60 min, and initial concentration of 12.245 mg/L) would be attained. The average triplicate value in ideal circumstances produced a removal effectiveness of 98.51%, demonstrating the proposed response surface\'s capacity for prediction. The findings of this investigation showed that the magnetic biochar nanocomposite that was created is an effective fluoride adsorbent.
摘要：
饮用水中的氟化物含量超过1.5mg/L是一个全球性的环境问题，可能严重危害人类健康。对水脱氟最有效的技术之一是吸附。许多吸附材料的主要缺点包括其吸附能力差，接触时间延长,过低或过高的pH值，和高剂量。本研究合成了生物炭基磁性纳米复合吸附剂，并将其用作水脱氟吸附剂。通过缓慢的热解，咖啡壳废物被转化为生物炭。通过将铁和镧的氧化物纳米颗粒化学共沉淀到生物炭的表面上而产生复合材料。通过X射线衍射分析(XRD),傅里叶变换红外光谱(FTIR),Brunauer-Emmett-Teller（BET），和pHPZC值，研究人员能够描述磁性生物炭纳米复合材料。中央复合材料设计（CCD），它使用四个输入变量，包括剂量(2-5g/L)，溶液pH（4-8），接触时间（30-70分钟），和初始浓度（10-20mg/L），被用来设计实验。二次模型表明，从水中去除98.994％的氟化物的理想条件（吸附剂用量为5gL-1，pH为5.74，接触时间为60min，初始浓度为12.245mg/L）。理想情况下的平均三倍值产生了98.51%的去除效果，证明了所提出的响应面的预测能力。这项研究的结果表明，所产生的磁性生物炭纳米复合材料是一种有效的氟化物吸附剂。
