纳米硅铝酸盐沸石晶体的合成及其对重金属的吸附机制

Synthesis of Nano-Aluminosilicate Zeolite Crystals and Its Adsorption Mechanism for Heavy Metals

在Linde F(K)沸石制备过程中引入双特征官能团长链有机物对沸石微观结构进行重构,限制其生长尺寸,合成纳米硅铝酸盐沸石晶体,旨在提高其对重金属的吸附能力。利用XRD、SEM、TEM、XPS等现代分析手段对对合成材料进行表征,研究其对水中重金属的吸附机制。结果表明,合成材料尺寸为200~500 nm,液相比表面积为2123.6 m^(2)/g。在单一吸附与复合吸附体系下,纳米沸石晶体对Cu和Cd吸附性能良好。随着pH增大与反应时间延长,材料对Cu和Cd的吸附量增加,且Cd>Cu。准二级动力学可拟合单一与复合吸附体系下纳米沸石晶体对水中Cu和Cd吸附过程,Langmuir等温式更适用于材料对Cu和Cd的吸附行为。与其它复合重金属吸附材料相比,纳米沸石晶体对重金属Cu与Cd的吸附效果良好。

The long-chain organics with double-featured functional groups was introduced to reconstruct the microstructure of zeolite,limit their growth size during the preparation process of material,to synthesize nano-aluminosilicate zeolite crystals,and enhance the adsorption ability of heavy metals.XRD,SEM,TEM,XPS and other modern analytical methods were used to characterize the synthetic materials.The adsorption mechanism of heavy metals on synthetic material was also investigated.The results showed that,the size of synthetic material was 200~500 nm,and the liquid surface area was 2123.6 m^(2)/g.In addition,in single adsorption or a composite adsorption system,nano-zeolite crystals had a significant adsorption performance on Cu and Cd.With the increase of pH value and reaction time,the adsorption capacity of Cu and Cd on the nanocrystalline material was enhanced,and the adsorption capacity of Cd>Cu.In single and composite adsorption systems,quasi-second-order kinetics could fit the adsorption process of Cu and Cd on nanozeolite crystals.Moreover,Langmuir isotherm was more suitable for the adsorption behavior of Cu and Cd.Compared with other composite heavy metal adsorption materials,nanozeolite crystals had a better adsorption effect on Cu and Cd.