荷叶基生物炭的制备及对水中氟离子的吸附研究

Preparation of Lotus Leaf-based Biochar and Its Adsorption Property for Fluorine Ion

以荷叶为原料,以KOH为活化剂,制备了高比表面积的荷叶基生物炭,利用扫描电镜和氮气吸脱附仪对样品的微观形貌和微观结构进行了表征,并对该荷叶基生物炭对水中氟离子的吸附性能进行了考察。结果表明,该荷叶基生物炭的比表面积为704.5 m^2/g,孔容为0.38 cm^3/g;可以明显看到生物炭表面均匀分布的大孔孔道;在质量浓度为10 mg/L的氟离子溶液中,氟离子在荷叶基生物炭上的吸附基本达到平衡;每100 mL氟离子溶液中加入1 g荷叶基生物炭时,除氟效果最佳,对氟离子的吸附容量为0.85 mg/g;荷叶基生物炭吸附动力学符合准二级动力学模型。

Lotus leaf-based biochar with high specific surface area is prepared by using lotus leaf as raw material and KOH as activator.Scanning electron microscopy(SEM)and nitrogen adsorption-desorption instrument are used to study the microstructure of the samples.The adsorption property of fluorine ions in water is also investigated.The results show that the specific surface area of lotus leaf-based biochar is 704.5 m 2/g,and the pore volume is 0.38 cm 3/g.The uniformly distributed macro-pore channels can be seen obviously by scanning electron microscopy.when the initial mass concentration of fluoride ion in solution is 10 mg/L,the adsorption equilibrium of lotus leaf-based biochar is attained after 60 min.The optimum dosage is 1 g/100 mL,and the maximum adsorption capacity of fluoride ions is 0.85 mg/g.The sorption kinetics of lotus leaf-based biochar conforms to quasi-second-order kinetic model.