不同硅铝比的ZSM-5型沸石分子筛吸附水中Cu2＋离子的研究

考察了3种不同硅铝比的ZSM-5沸石分子筛（25H、38H和50H，25、38和50为硅铝比）对水中Cu2＋的吸附过程及其影响因素。结果表明，3种材料均能有效吸附去除水中Cu2＋离子，动力学符合假二阶动力学模型，吸附等温线符合Langmuir吸附等温式。3种材料吸附速率及吸附容量顺序为：25H〉50H〉38H，其中，25H最大吸附容量达到12．83mg／g。投加量由0．8g／L增加至2．0g／L，材料对Cu2＋吸附去除率由87．0％增加至97．5％。考察水中常见阳离子对吸附的干扰作用，结果表明，干扰离子的影响顺序为：Pb2＋〉K＋〉Na＋〉Mg2＋；随着干扰离子浓度的增大，材料对Cu2＋的去除率显著下降。硅铝比及晶粒形貌均对沸石分子筛吸附Cu2＋有较大影响，小的孔径不利于Cu2＋的吸附，低硅铝比有利于Cu2＋在分子筛上的吸附。

Study on adsorption of Cu2＋ from aqueous solution by ZSM-5 molecular sieve of different SiO2/Al2O3 ratios

Adsorption of Cu2＋ from aqueous solution by three kinds of ZSM-5 molecular sieve （25H, 38H, 50H, 25, 38 and 50 were SiO2/Al2O3 ratio） was investigated. The results showed that the ZSM-5 molecular sieves could adsorb Cu2＋ from aqueous solution effectively. The adsorption process attributes to pseudo seeond- order kinetics model and the equilibrium isotherm for Cu2＋ uptake corresponds closely to the Langmuir model. The corresponding sequence of adsorption rate and capacity was： 25H 〉 50H 〉 38H. The maximum adsorption eapaeity of 25H was up to 12.83 mg/g. As the adsorbent dosage inereased from 0.8 g/L to 2.0 g/L, the removal rate in- creased from 87.0% to 97.5% eorrespondingly. The common cations could affect the adsorption process, the corresponding sequence was Pb2＋ 〉 K ＋ 〉 Na ＋ 〉 Mg2＋. And higher eoncentration of eo-existing cation had greater influence on adsorption removal efficiency. The SiO2/Al2O3 ratio and morphology features both have influenee on Cu2＋ adsorption, small pore size disbennifits adsorption, and low SiO2/Al2O3 ratio facilitates adsorption.