粉煤灰基P型沸石吸附水中Cu^(2+)和Cd^(2+)

Adsorption of Cu^(2+) and Cd^(2+) in water by fly ash-based zeolite P

以粉煤灰(FA)为原料经水热反应合成了P型沸石(Z-P).采用X射线荧光光谱仪、X射线衍射仪、场发射环境扫描电子显微镜、比表面孔径分析仪、傅里叶变换红外光谱仪和X射线光电子能谱对Z-P进行表征,并研究了其对Cu^(2+)和Cd^(2+)的吸附性能.结果表明,Z-P的BET比表面积和孔隙体积分别为38.46m^(2)/g和0.2180cm^(3)/g,均高于FA的1.273m^(2)/g和0.0120cm^(3)/g.FA、Z-P对Cu^(2+)和Cd^(2+)的吸附更符合拟二级动力学模型和Langmuir等温线模型.Z-P对Cu^(2+)和Cd^(2+)的最大吸附量分别为157.48,131.57mg/g,远高于于FA的30.88,25.47mg/g.Z-P对Cd^(2+)的循环再生吸附效果好,但对Cu^(2+)的循环再生吸附效果较差.离子强度对Z-P吸附Cu^(2+)和Cd^(2+)分别起促进和抑制作用.表明Z-P可以作为有效且廉价的Cu^(2+)、Cd^(2+)吸附剂,为FA的资源化利用和含Cu^(2+)、Cd^(2+)重金属离子废水吸附剂的开发提供了一种方法.

Zeolite P(Z-P)was synthesized from fly ash(FA)by hydrothermal reaction.Z-P was characterized by X-ray fluorescence spectrometer,X-ray diffractometer,field emission environmental scanning electron microscope,specific surface aperture analyzer,Fourier transform infrared spectrometer and X-ray photoelectron spectroscopy,and its adsorption properties for Cu^(2+)and Cd^(2+)were studied.The results showed that the BET specific surface area and pore volume of Z-P were 38.46m^(2)/g and 0.2180cm^(3)/g,respectively,which were higher than those of FA(1.273m^(2)/g and 0.0120cm^(3)/g).The adsorption of Cu^(2+)and Cd^(2+)by FA and Z-P was more in line with the pseudo-second-order kinetic model and the Langmuir isotherm model.The maximum adsorption capacities of Cu^(2+)and Cd^(2+)by Z-P were 157.48 and 131.57mg/g,respectively,which were much higher than those of FA(30.88 and 25.47mg/g).Z-P showed good cyclic regeneration and adsorption of Cd^(2+),but it showed poor cyclic regeneration and adsorption of Cu^(2+).The ionic strength promoted and inhibited the adsorption of Cu^(2+)and Cd^(2+)by Z-P,respectively.This paper shows that Z-P can be used as an effective and cheap adsorbent for Cu^(2+)and Cd^(2+),which provides a method for the resource utilization of FA and the development of adsorbent for wastewater containing heavy metal ions of Cu^(2+)and Cd^(2+).