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

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 m²/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.