State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming, 650093, China.
State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming, 650093, China.
Chemosphere. 2022 Aug;301:134676. doi: 10.1016/j.chemosphere.2022.134676. Epub 2022 Apr 19.
Molecular sieves have also been used for arsenic adsorption in recent years because of their special structure. In order to solve the problem of arsenic pollution in drinking water and/or industrial wastewater, ZSM-5/Fe adsorbent was prepared by loading iron on ZSM-5 molecular sieve. It is also used as an excellent adsorbent for removing arsenic and other heavy metal ions from industrial wastewater. At room temperature, the concentration of arsenic was reduced from 100 mg/L to 0.006 mg/L after the solution pH was adjusted to the range of weak acid to weak base (4-10) and 0.5 g of ZSM-5/Fe adsorbent was added for reacting 2 h. The adsorption capacity reached 40.00 mg/g, the adsorption efficiency reached 99.99%, reaching the national standard of drinking water. Adsorption thermodynamics, kinetics and isotherms showed that the adsorption mechanism of arsenic is heterogeneous nucleation adsorption (including electrostatic attraction and chemical precipitation). Moreover, ZSM-5/Fe adsorbent can adjust pH spontaneously by using non-skeleton Si-Al phase to achieve effective adsorption from weak acid to weak base. At the same time, ZSM-5/Fe adsorbent showed good reusability and stability in five cycles. This study provides an important idea for the application of ZSM-5 molecular sieve in many fields and the efficient removal of arsenic from drinking water and industrial wastewater.
近年来，分子筛由于其特殊的结构也被用于砷的吸附。为了解决饮用水和/或工业废水中的砷污染问题，通过将铁负载在 ZSM-5 分子筛上制备了 ZSM-5/Fe 吸附剂，它也被用作去除工业废水中砷和其他重金属离子的优良吸附剂。在室温下，将溶液的 pH 值调节至弱酸至弱碱范围（4-10），并添加 0.5 g 的 ZSM-5/Fe 吸附剂反应 2 h 后，砷的浓度从 100 mg/L 降低至 0.006 mg/L。吸附容量达到 40.00 mg/g，吸附效率达到 99.99%，达到饮用水的国家标准。吸附热力学、动力学和等温线表明，砷的吸附机制是异质成核吸附（包括静电吸引和化学沉淀）。此外，ZSM-5/Fe 吸附剂可以通过利用非骨架 Si-Al 相自动调节 pH 值，从而实现从弱酸到弱碱的有效吸附。同时，ZSM-5/Fe 吸附剂在五个循环中表现出良好的可重复使用性和稳定性。本研究为 ZSM-5 分子筛在许多领域的应用以及从饮用水和工业废水中高效去除砷提供了重要思路。
