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研究了不同p H值、初始Cr3+浓度、温度、反应时间等条件下蒙脱石对Cr3+及螯合物[Cr(phen)3]3+的吸附行为,探讨了电动电位变化与吸附性能的关系。结果表明:蒙脱石吸附[Cr(phen)3]3+性能明显优于吸附Cr3+的性能,其主要原因在于蒙脱石对[Cr(phen)3]3+的吸附是静电引力及氢键、范德华力共同作用的结果,并且这种吸附能力基本不受介质酸碱性的影响。动力学研究表明两种吸附均符合准二级反应动力学模型。热力学研究表明蒙脱石对[Cr(phen)3]3+和Cr3+的吸附符合Langmuir的单层吸附模型。蒙脱石对[Cr(phen)3]3+和Cr3+的吸附的ΔG均小于零,而ΔH、ΔS都大于零,因此2种吸附均为自发、吸热和更无序的。
The adsorption behavior of Cr3 + and chelate [Cr (phen) 3] 3 by montmorillonite with different p H value, initial Cr3 + concentration, temperature and reaction time was studied. The relationship between the change of electromotive potential and the adsorption capacity . The results show that the adsorption of [Cr (phen) 3] 3 on montmorillonite is better than the adsorption on Cr3 +. The main reason is that the adsorption of [Cr (phen) 3] 3 by montmorillonite is electrostatic attraction and hydrogen bond , Van der Waals forces together, and the adsorption capacity of the basic medium from the acid-base impact. Kinetic studies show that both adsorption are in line with quasi-second-order reaction kinetics model. Thermodynamic studies show that montmorillonite adsorption of [Cr (phen) 3] 3+ and Cr3 + conforms to Langmuir’s monolayer adsorption model. ΔG of montmorillonite adsorption to [Cr (phen) 3] 3+ and Cr3 + is less than zero, and both ΔH and ΔS are greater than zero, so both adsorptions are spontaneous, endothermic and more disorderly.