摘要
以粉煤灰(FA)为原料水热合成了不同铝硅物质的量比(Al/Si)的介孔铝取代托贝莫来石(TFA).采用X射线荧光光谱仪(XRF)、X射线衍射仪(XRD)、场发射环境扫描电子显微镜(SEM)、比表面孔径分析仪和傅里叶变换红外光谱仪(FTIR)对FA及制备的TFA的理化性质进行表征.结果表明,TFA1(Al/Si=0.4)的比表面积、孔隙体积和平均孔径分别为74.30m^(2)/g、0.4495cm^(3)/g和24.20nm,TFA2(Al/Si=0.1)的分别为99.48m^(2)/g、0.5218cm^(3)/g和20.98nm,均远高于FA的1.77m^(2)/g、0.004338cm^(3)/g和9.79nm.FA、TFA1和TFA2对Cd^(2+)的吸附动力学数据更加符合伪二级动力学模型.Langmuir等温线模型可以更好地描述Cd^(2+)的吸附等温线,TFA1对Cd^(2+)的饱和吸附量为205.76mg/g,远高于FA和TFA2的94.58mg/g和107.30mg/g.采用XRD、SEM-X射线能量色散谱仪和FTIR分析了TFA对Cd^(2+)的去除机理.结果表明TFA的介孔结构、大量的-OH、Ca^(2+)与Cd^(2+)的离子交换,以及CdCO_(3)和Cd(OH)_(2)的沉淀对Cd^(2+)的去除起着重要作用.本文表明TFA可以应用为一种高效又廉价的Cd^(2+)吸附剂,为FA的资源化利用和含Cd^(2+)等重金属离子废水的处理提供了一种潜在的应用方法.
Mesoporous aluminum-incorporated tobermorite(TFA)with different Al/Si molar ratios were hydrothermally synthesized from fly ash(FA).The physicochemical properties of FA and TFA were characterized by X-ray fluorescence(XRF),X-ray diffraction(XRD),Field emission environment scanning electron microscope(SEM),Specific surface aperture analyzer,and Fourier transform infrared spectroscopy(FTIR).It was found that the specific surface area,pore volume and average pore size of TFA1(Ai/Si=0.4)were 74.30m^(2)/g,0.4495cm^(3)/g and 24.20nm,respectively,while those of TFA2(Ai/Si=0.1)were 99.48m^(2)/g,0.5218cm^(3)/g and 20.98nm,respectively.They were much higher than those of FA(1.77m^(2)/g,0.004338cm^(3)/g and 9.79nm).The adsorption kinetics data of FA,TFA1 and TFA2 for Cd^(2+)were more consistent with the pseudo-second-order kinetics model.The Langmuir isotherm model provided better description of the Cd^(2+)adsorption isotherm,and the maximum adsorption capacity for Cd^(2+)on TFA1 was 205.76mg/g,which was much higher than those on FA and TFA2(94.58mg/g and 107.30mg/g).The removal mechanism of Cd^(2+)on TFA were analyzed by XRD,SEM-X-ray energy dispersive spectrometer and FTIR.The results show that the mesoporous structure of TFA,a large amount of-OH,the ion exchange of Ca^(2+)and Cd^(2+),and the precipitation of CdCO_(3) and Cd(OH)_(2) played important roles in removing Cd^(2+).This work shows that the TFA can be used as an efficient and inexpensive adsorbent for Cd^(2+),which provides a potential application method for resource utilization of FA and the treatment of wastewater containing Cd^(2+)and other heavy metal ions.
作者
徐霖浩
郑博英
杨龙生
吴代赦
汪泽华
XU Lin-hao;ZHENG Bo-ying;YANG Long-sheng;WU Dai-she;WANG Ze-hua(School of Resources and Environment,Nanchang University,Nanchang 330031,China;Key Laboratory of Poyang Lake Environment and Resources Utilization,Ministry of Education,Nanchang 330031,China;School of Materials and Chemical Engineering,Pingxiang University,Pingxiang 337000,China)
出处
《中国环境科学》
EI
CAS
CSCD
北大核心
2023年第4期1663-1671,共9页
China Environmental Science
基金
国家自然科学基金资助项目(52004128)。
