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通过静态吸附实验,采用强碱性离子交换纤维(SAAEF)去除水溶液中的Cr(VI)。分别研究了时间、Cr(Ⅵ)的初始浓度和pH对该吸附过程的影响。SAAEF的最大饱和吸附量为187.7mg/g(pH=1)。饱和吸附量随着Cr(VI)浓度的升高而增大,在pH>1的酸度范围内,随着pH值的增高而减少。采用Langmuir、Freundlich、Dubinin-Radushkevich和Temkin4种热力学模型对不同温度的等温吸附曲线进行拟合,结果表明,Langmuir等温吸附模型是描述SAAEF吸附Cr(VI)热力学过程的最佳模型;模型参数表明,SAAEF吸附Cr(VI)的过程既存在物理吸附又存在化学吸附。热力学参数ΔH、ΔG和ΔS表明,该吸附过程为一放热、熵增的自发过程。热力学参数Q(iso)不为常量,表明SAAEF表面存在能量分布不均匀的现象。
Cr (VI) in aqueous solution was removed by static adsorption experiments using strongly basic ion exchange fiber (SAAEF). The effects of time, initial Cr (Ⅵ) concentration and pH on the adsorption process were studied. The maximum saturated adsorption capacity of SAAEF is 187.7 mg / g (pH = 1). The saturated adsorption increased with the increase of Cr (VI) concentration, but decreased with the increase of pH in the range of pH> 1. The adsorption isotherms of Langmuir, Freundlich, Dubinin-Radushkevich and Temkin were fitted to the isothermal adsorption curves of different temperature. The results showed that the Langmuir isotherm adsorption model is the best model to describe the thermodynamic process of SAAEF adsorption Cr (VI) SAAEF adsorption of Cr (VI) in the process of both physical adsorption and the existence of chemical adsorption. The thermodynamic parameters ΔH, ΔG and ΔS indicate that the adsorption process is an exothermic and entropy-increasing spontaneous process. The thermodynamic parameters Q (iso) are not constant, indicating that there is a phenomenon of uneven energy distribution on the SAAEF surface.