WBC-Fe的制备及其除氟性能

Preparation of WBC-Fe and its fluoride removal performance

采用高温热解法制备铁改性的梧桐叶生物炭(WBC-Fe)并优化制备工艺,同时使用扫描电子显微镜(SEM)、X射线衍射(XRD)、傅里叶变换红外光谱(FTIR)和EDS能谱对材料进行表征。通过静态吸附实验,将该材料用于含氟模拟废水的实验研究。结果表明:以F-吸附量为主要指标,WBC-Fe的最佳制备工艺为氯化铁浓度1 mol/L、热解温度400℃、热解时间1 h;该材料含有较丰富的含氧官能团,且表面有铁元素成功负载;当F-溶液初始浓度为11.80 mg/L、pH值为6.5、温度为30℃、投加量为3 g/L、吸附时间为4 h时,F-在该材料表面的吸附达到平衡,此时F-吸附量为3.70 mg/g,是未改性生物炭(WBC)的7倍。Langmuir模型、二级动力学方程能较好的描述F-在WBC-Fe表面的吸附行为,表明其对F-的吸附以单层吸附为主,且受化学作用控制,可能是该材料表面负载的三价铁与F-之间存在较好配位作用的结果。

Using phoenix tree leaf as raw material,iron-modified biochar named as WBC-Fe was prepared by high temperature pyrolysis.And the preparation process was optimized.At the same time,the material was characterized by scanning electron microscopy(SEM),X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR)and EDS energy spectrum analysis.The material was used in the experimental study of simulated wastewater containing fluorine by static adsorption experiment.The results showed that the optimum preparation process was selected as follows:ferric chloride concentration of 1 mol/L,pyrolysis temperature of 400℃,pyrolysis time of 1 h.The material contains abundant oxygen-containing functional groups,and the iron element is successfully loaded on the surface.And when the initial concentration of F-is 11.80 mg/L,pH is 6.5,the temperature is 30℃,the dosage is 3 g/L,and the adsorption time is 4 h,the adsorption reaches equilibrium.The adsorption capacity is 3.70 mg/g,which is 7 times of that of unmodified biochar(WBC).The Langmuir model and second-order kinetic equation can well describe the adsorption behavior of F-on the WBC-Fe surface,indicating that the adsorption of F-on the material is mainly monolayer adsorption and controlled by chemical interaction,which may be the result of the good coordination between F-and the ferric iron loaded on the surface of the material.