Sorption behavior of cesium from aqueous solution on magnetic hexacyanoferrate materials

• Published in: Nuclear engineering and design 2014-08, Vol.275, p.322-328
• Main Authors: Zhang, Hengxuan, Zhao, Xuan, Wei, Jiying, Li, Fuzhi
• Format: Article
• Language: English
• ISSN: 0029-5493; 1872-759X
• DOI: 10.1016/j.nucengdes.2014.05.006

•A novel pathway of synthesizing magnetic hexacyanoferrate material was developed.•The synthesized material can offer a high capacity for sorption of cesium.•The material can offer a fast removal of cesium in kinetic performance.•The fine M-PTH particle can be easily separated from wastewater for recirculation. The rapid development of the nuclear power plant in China leads to increasing attention to the treatment of low-level radioactive wastewater (LLRW). One of possibilities is the application of inorganic adsorbent like potassium titanium hexacyanoferrate (PTH), which can exhibit the effective adsorption of cesium. In this paper, the PTH material was optimized by means of being loaded on magnetite substrate. The synthesized material (magnetic PTH, M-PTH), with a particle size of less than 100nm, can offer a high capacity and favorable kinetic performance, however, without difficulties of separation from the LLRW due to its magnetic characterizations. The batch experiments demonstrate that cesium sorption isotherm of M-PTH coincide well with Langmuir model. The calculated capacity amounts to 0.517mmol/g, approximately 1.5 times the capacity of zeolite materials. The sorption process follows the pseudo-second-order sorption model. In the initial phase the rate-controlling step is intraparticle diffusion. With the Cs accumulation on the particle surface, external diffusion performs an important role together with intraparticle diffusion.