摘要
制备了一种磁性羟基磷灰石/生物炭复合材料(HAP/γ-Fe_2O_3/BC)并对其吸附Pb^(2+)的动力学及热力学特性和固液分离回收性能进行了研究.通过扫描电子显微镜(SEM)、X射线衍射(XRD)、傅里叶红外光谱仪(FTIR)等对复合前后的材料进行微观结构表征与分析,利用振动样品磁强计(VSM)研究样品的磁化性能.通过参数计算获得吸附方程与热力学性质.结果表明:羟基磷灰石和γ-Fe_2O_3微粒均负载到生物炭上.相对于BC,复合后的HAP/γ-Fe_2O_3/BC对Pb^(2+)的吸附性能明显提高,并具有良好的磁分离能力.pH值对Pb^(2+)的吸附影响较大,最佳pH值为4.0～5.0.当吸附剂投加量为1 g·L^(-1)、pH值为5、Pb^(2+)的初始浓度为100 mg·L^(-1)时,HAP/γ-Fe_2O_3/BC对Pb^(2+)的去除率达到99%.吸附等温方程和动力学方程的拟合结果分别符合Langmuir吸附等温模型和准二级动力学模型,热力学参数△G<0、△H>0,是自发吸热的单分子层化学吸附过程.吸附机制主要包括溶解-沉淀作用、离子交换及复合材料表面含氧官能团的络合作用.HAP/γ-Fe_2O_3/BC复合材料在外加磁场的作用下具有良好的分离回收和循环利用性能,是一种潜在的Pb^(2+)高效吸附材料.
A magnetic hydroxyapatite/biochar composite （ HAP/γ-Fe2O3/BC） was prepared and the adsorption thermodynamic properties of Pb2＋ and solid-liquid separation recovery performance were studied. The micro-structures of the samples before and after recombination were characterized and analyzed by using scanning electron microscopy （ SEM）, X-ray diffraction （XRD） and Fourier transform infrared spectroscopy （ FTIR）. The magnetization properties of the samples were studied using a vibrating sample magnetometer （VSM）. Adsorption equations and thermodynamic properties are obtained through parameter calculations. The results show that both hydroxyapatite and T-Fe203 particles were loaded onto biochar. Compared to BC, the adsorption performance of HAP/γ-Fe2O3/BC for Pb2＋ is obviously improved and good magnetic separation ability is obtained, pH has a great influence on the adsorption of Pb2＋ and the optimum pH is 4.0 ~ 5.0. under the adsorbent dosage of 1 g· L-1 , pH 5, and the initial concentration of Pb2＋ at 100 mg· L-1 , the adsorption of Pb2＋ by HAP/T-Fe2O3/BC reaches 99%. The fitting results of adsorption isotherm equations and kinetic equations are consistent with the Langmuir adsorption isotherm model and pseudo-second order kinetics model respectively. The thermodynamic parameters （△ G〈0, A H〉0） indicate that the adsorption is a spontaneous endothermic monolayer chemisorption process. The adsorption mechanism mainly includes dissolution-precipitation, ion exchange, and the complexation of oxygen-containing functional groups on the surface of the composite. HAP/T-Fez O3/BC composite shows good separation and recycling performance under an external magnetic field, indicating the composite is an efficient adsorption material for Pb2＋ removal.
作者
张连科
王洋
王维大
李玉梅
孙鹏
韩剑宏
姜庆宏
ZHANG Lianke;WANG Yang;WANG Weida;LI Yumei;SUN Peng;HAN Jianhong;JIANG Qinghong(School of Energy and Environment,Inner Mongolia University of Science and Technology,Baotou 014010;School of Environment and Municipal Engineering,Xi＇an University of Architecture and Technology,Xi＇an 710055)
出处
《环境科学学报》
CAS
CSCD
北大核心
2018年第11期4360-4370,共11页
Acta Scientiae Circumstantiae
基金
内蒙古自然科学基金(No.2016MS0221)
包头市科技计划项目(No.2016X1021)
内蒙古科技大学产学研合作培育基金项目(No.2016CXY03)~~
作者简介
张连科（1980-），男，副教授，E—mail：lkzhang@126．com；责任作者
