High-efficiency continuous enrichment of cesium ions using CuFC composite microspheres: dynamic adsorption and mechanism
- PDF / 5,218,684 Bytes
- 15 Pages / 595.276 x 790.866 pts Page_size
- 64 Downloads / 239 Views
High‑efficiency continuous enrichment of cesium ions using CuFC composite microspheres: dynamic adsorption and mechanism analysis Xi Chen1 · Ye Li1 · Lijun Zhu1 · Yi Ke1 · Xiaoli Wang1 · Yixuan Yang1 Received: 22 April 2020 © Akadémiai Kiadó, Budapest, Hungary 2020
Abstract In this study, we proposed a novel multi-walled carbon nanotubes (MWCNT) doping strategy. Based on the composite cross-linking effect, CuFC was encapsulated by Calcium alginate (CA), and Polyvinyl alcohol (PVA), and MWCNT were introduced into the pellet-forming process to form composite microsphere with excellent mechanical strength. The composite microsphere was characterized by FT-IR, XRD, SEM, EDS and XPS spectrometry. The composite microsphere filled column has excellent adsorption performance and can be used for continuous adsorption of Cs+. The dynamic adsorption behavior was well fitted by the Thomas model and the Yoon–Nelson model. Therefore, CuFC composite microsphere has promising potential for Cs+ continuous adsorption from radioactive wastewater. Keywords CuFC composite microspheres · Cesium · Enrichment · Dynamic adsorption
Introduction Cesium, which exists in almost all contaminated radioactive wastewater [1], has long-term radioactivity and toxicity and seriously endangers environmental security. Organisms easily absorb cesium due to its chemical properties similar to potassium [2]. It is distributed evenly throughout the body and mainly stays in the soft tissue of the whole body, causing acute and chronic injuries. However, cesium is also a valuable metal, widely used in industry, agriculture and medical treatment [3, 4]. Considering the harmfulness and resource of cesium, it is urgent to enrich and remove cesium from radioactive wastewater. In addition to the general characteristics, radionuclide adsorption materials also need to have certain stability and radiation resistance [5]. Among many adsorption materials, adsorption technology is a commonly used radionuclide enrichment technology due to its economy and adaptability, and it has been extensively studied in the treatment of highemission waste liquids [6, 7]. So far, the main adsorbents used to remove cesium include inorganic minerals [8], Prussian blue analogs [9–11], heteropoly salts [12, 13], ferrous * Ye Li [email protected] 1
School of Resources and Environmental Engineering, Wuhan University of Technology, Wuhan 430070, China
cyanide [14–16], polyvalent metallic phosphates [17] and so on. Among them, the adsorption equilibrium time of inorganic minerals is too long to meet the timeliness of rapid enrichment detection. Due to its fine particle size, heteropoly salts can not be continuously adsorbed by packed adsorption column, limiting its application. The problem of sulphate loss in the practical application of polyvalent metallic phosphate remains to be solved. Metal ferrocyanide is classified into soluble and insoluble ions due to the difference of interstitial ions in the crystal lattice, and both of them take the form of cubic crystals [18, 19]. Althoug
