Centre for Surface Chemistry and Catalysis, KU Leuven , Kasteelpark Arenberg 23 - box 2461, 3001 Heverlee, Belgium.
Environ Sci Technol. 2015 Feb 3;49(3):1729-37. doi: 10.1021/es505345r. Epub 2015 Jan 27.
Construction of multibarrier concrete based waste disposal sites and management of alkaline mine drainage water requires cation exchangers combining excellent sorption properties with a high stability and predictable performance in hyper alkaline media. Though highly selective organic cation exchange resins have been developed for most pollutants, they can serve as a growth medium for bacterial proliferation, impairing their long-term stability and introducing unpredictable parameters into the evolution of the system. Zeolites represent a family of inorganic cation exchangers, which naturally occur in hyper alkaline conditions and cannot serve as an electron donor or carbon source for microbial proliferation. Despite their successful application as industrial cation exchangers under near neutral conditions, their performance in hyper alkaline, saline water remains highly undocumented. Using Cs(+) as a benchmark element, this study aims to assess the long-term cation exchange performance of zeolites in concrete derived aqueous solutions. Comparison of their exchange properties in alkaline media with data obtained in near neutral solutions demonstrated that the cation exchange selectivity remains unaffected by the increased hydroxyl concentration; the cation exchange capacity did however show an unexpected increase in hyper alkaline media.
建设多屏障混凝土垃圾处理场和管理碱性矿山排水需要阳离子交换剂，这些交换剂应具有良好的吸附性能、在高碱性介质中的高稳定性和可预测的性能。尽管已经开发出了针对大多数污染物的高选择性有机阳离子交换树脂，但它们可能成为细菌增殖的生长介质，从而影响其长期稳定性，并为系统的演变引入不可预测的参数。沸石是一类无机阳离子交换剂，它们在高碱性条件下自然存在，不能作为微生物增殖的电子供体或碳源。尽管它们在近中性条件下作为工业阳离子交换剂成功应用，但它们在高碱性、含盐水中的性能仍未得到充分记录。本研究以 Cs(+) 为基准元素，旨在评估沸石在混凝土衍生水溶液中的长期阳离子交换性能。比较碱性介质中的交换性能与近中性溶液中获得的数据表明，阳离子交换选择性不受羟基浓度增加的影响；然而，阳离子交换容量在高碱性介质中出人意料地增加。
