Preparing High-Loaded Potassium Cobalt Hexacyanoferrate/Silica Composite for Radioactive Wastewater Treatment

• Published in: Nuclear technology Vol. 165; no. 2; pp. 200 - 208
• Main Authors: Liu, Hai-Di, Li, Fu-Zhi, Zhao, Xuan, Yun, Gui-Chun
• Format: Journal Article
• Language: English
• Published: La Grange Park, IL Taylor & Francis 01.02.2009; American Nuclear Society
• Subjects: Applied sciences; Exact sciences and technology; Pollution; Radioactive wastes; Wastes; Radioactive waste; Hexacyanoferrates; radioactive wastewater; Cesium; Inorganic adsorbent; Cobalt; Silica; Composite material; potassium cobalt hexacyanoferrate; Decontamination; X ray diffractometry; Waste water purification; Scanning transmission electron microscopy; Potassium
• ISSN: 0029-5450; 1943-7471
• DOI: 10.13182/NT09-A4086

We developed a new method for the preparing of a potassium cobalt hexacyanoferrate (PCH)/SiO 2 composite as a granulated inorganic adsorbent to remove Cs + from the radioactive waste solution. The process comprised two steps: The first step was preparing nanoscaled PCH particles, and the second step was stabilizing the PCH particles into the in situ-generated porous silica with aqueous silica sol used as SiO 2 source. Granulated composite particles with good rigidity could be successfully prepared with this method. At the same time, the PCH content in the composite could reach 70 wt%, which is one of the highest PCH loads that have been reported. The PCH particles and composite were analyzed with X-ray diffraction, transmission electron microscopy, scanning electron microscopy, energy-dispersive analysis of X-rays, and Brunauer-Emmett-Teller methods. It was indicated by the results that the PCH particles and porous silica were mixed with each other homogeneously in the composite. Adsorption behaviors of the composite upon Cs + under competition of coexisting ions (H + , Na + , and K + ) were studied in batch experiments to determine the distribution coefficient (K d ). The as-fabricated composite exhibited high Cs adsorbing capacity (0.335 meq Cs/g composite) and good Cs + selectivity from the mixture of competing ions (H + , Na + , and K + ). All these characteristics made it a promising material for treating radioactive wastewater.