13X分子筛去除水中重金属离子Cr^(3+)的研究

Removing Heavy Metal Chromium(Ⅲ) of the Water by 13X Molecular Sieve

以13X分子筛作为吸附剂,研究废水中Cr3+的去除。考察了水的pH、Cr3+浓度和吸附时间的影响,通过对不同价态金属离子的吸附探讨了除Cr3+机理,比较了13X分子筛和732型阳离子交换树脂对Cr3+的去除效果。结果表明:水的pH等条件对Cr3+的去除有较大影响;13X分子筛对Cr3+的吸附机理以离子交换吸附为主,符合Langmuir等温吸附模型和Lagergren二级动力学方程,吸附速率控制步骤为颗粒内扩散;达到吸附平衡后,分子筛对Cr3+的去除率为92.2%;分子筛吸附Cr3+的二级反应速率常数为0.004 5 g/(mg.min),比阳离子交换树脂的相应值大。

The treatment effect of molecular sieve to heavy metal wastewater was researched with 13X molecular sieve as adsorption materials.The influences of pH value of wastewater,the concentration of Cr 3 ＋ and adsorption time were investigated.Mechanism of Cr3＋ removal was discussed through the adsorption of different valent metal ions.Removal efficiency between 13X molecular sieve and 732 cation exchange resins were compared.Results showed that all the experimental conditions such as pH value of wastewater had great influence on the removal of Cr 3＋.The main adsorption way to Cr3＋with 13X molecular sieve is ion change adsorption which consistent with Langmuir model and secondary dynamic equation.The control step of adsorption rate is intra particle transport.Removal rate can reach 92.2% after adsorption equilibrium.The secondary adsorption rate is 0.004 5 g/（mg.min）.It is better than the corresponding values of the cation exchange resins.