Novel vanadosilicate is potential decontamination agent for cesium-tainted water
The Fukushima reactor disaster has been the most recent incident to introduce the public to the concept of “cesium 137”. In the journal Angewandte Chemie, Korean researchers have now introduced a new vanadosilicate that can remove cesium from contaminated coolant water, liquid nuclear waste, and contaminated ground- and seawater more effectively than conventional sorbents.
Cs-137 is among the most dangerous radioactive nuclides. It has a half-life of 30 years, so contaminated areas remain polluted for a long time. The high solubility of cesium salts in water facilitates its dispersal in the environment and its uptake by plants. If humans ingest this contaminated food, the body cannot differentiate the cesium from potassium, so the toxin is stored in muscle tissue. Larger amounts can cause severe radiation sickness; smaller amounts can cause diseases like cancer.
The removal of Cs-137 from contaminated ground- and seawater, as well as liquid nuclear waste from reprocessing and nuclear energy plants is correspondingly critical for public health. The problem is the very high relative concentrations of competing cations like sodium, calcium, magnesium, and potassium ions—which make necessary a highly effective and selective cesium trap. A wide variety of inorganic materials have been developed, although there has been no substantial progress in the last 20 years. To date, titanosilicates have worked best, and these were put into use after the Fukushima reactor disaster.
Kyung Byung Yoon and a team from Sogang University in Seoul, South Korea have now developed a new material named as “Sogang University-45” (or SGU-45 for short) that very effectively binds and immobilizes cesium from groundwater, seawater, and liquid nuclear waste. Under the test conditions used, in concentrations of 10 ppb to 100 ppm, SGU-45 was shown to be superior to all previous materials with regard to selectivity, capacity, and rate of absorption. Strikingly, unlike other materials, the selectivity of K-SGU-4, the variant loaded with potassium ions, to cesium increases as the cesium concentration decreases.
SGU-45 is a special, microporous vanadosilicate with vanadium ions in the 4+ and 5+ oxidation states. K-SGU-45 was best suited for the removal of cesium from contaminated groundwater and seawater, as well as strongly acidic or basic nuclear waste. The cesium ions absorbed replace the potassium ions in K-SGU-45. The framework of SGU-45 already carries non-exchangeable cesium ions which are 16-coordinate, meaning that they have 16 neighboring atoms bonded to cesium. This observation is of academic interest because this is the highest coordination number (the number of nearest neighbors in a crystal lattice or complex) yet observed in chemistry.
About the Author
Dr. Kyung Byung Yoon is Professor of Chemistry at Sogang University, Seoul, Korea. He is also the Director of the Korea Center for Artificial Photosynthesis. He has been working in the area of zeolite research for the last 30 years. He is the recipient of the Korea Science Award and the Academic Award from the National Academy of Science, Korea.
Author: Kyung Byung Yoon, Sogang University, Seoul (Rep. Korea), http://hompi.sogang.ac.kr/zeolite/eyoon.htm
Title: A Novel Vanadosilicate with Hexadeca-Coordinated Cs+ Ions as a Highly Effective Cs+ Remover
Angewandte Chemie International Edition, Permalink to the article: http://dx.doi.org/10.1002/anie.201402778
Dr. Kyung Byung Yoon | Angewandte Chemie
Two decades of training students and experts in tracking infectious disease
27.11.2015 | Hochschule für Angewandte Wissenschaften Hamburg
Increased carbon dioxide enhances plankton growth, opposite of what was expected
27.11.2015 | Bigelow Laboratory for Ocean Sciences
Planet Earth experienced a global climate shift in the late 1980s on an unprecedented scale, fuelled by anthropogenic warming and a volcanic eruption, according to new research published this week.
Scientists say that a major step change, or ‘regime shift’, in the Earth’s biophysical systems, from the upper atmosphere to the depths of the ocean and from...
The Fraunhofer Institute for Solar Energy Systems ISE has installed 70 photovoltaic modules on the outer façade of one of its lab buildings. The modules were...
Nerve cells cover their high energy demand with glucose and lactate. Scientists of the University of Zurich now provide new support for this. They show for the first time in the intact mouse brain evidence for an exchange of lactate between different brain cells. With this study they were able to confirm a 20-year old hypothesis.
In comparison to other organs, the human brain has the highest energy requirements. The supply of energy for nerve cells and the particular role of lactic acid...
In laser material processing, the simulation of processes has made great strides over the past few years. Today, the software can predict relatively well what will happen on the workpiece. Unfortunately, it is also highly complex and requires a lot of computing time. Thanks to clever simplification, experts from Fraunhofer ILT are now able to offer the first-ever simulation software that calculates processes in real time and also runs on tablet computers and smartphones. The fast software enables users to do without expensive experiments and to find optimum process parameters even more effectively.
Before now, the reliable simulation of laser processes was a job for experts. Armed with sophisticated software packages and after many hours on computer...
Researchers at Heidelberg University have devised a new way to study the phenomenon of magnetism. Using ultracold atoms at near absolute zero, they prepared a...
25.11.2015 | Event News
17.11.2015 | Event News
21.10.2015 | Event News
27.11.2015 | Press release
27.11.2015 | Life Sciences
27.11.2015 | Materials Sciences