Radioactive Water Decontamination Improved by NIMS Scientists
Researchers at Japan's NIMS (National Institute for Materials Science) have discovered a new nanoscale material which is highly effective in removing radioactive strontium and radioiodine from contaminated water.
The material is made from silica punctured with tiny holes ranging from 2 to 20 nanometers in diameter. Each hole is lined with a special compound engineered to bind with either radioiodine or strontium, facilitating the removal of these toxic radioactive isotopes from contaminated water... and Japan has plenty of contaminated water right now.
Although similar materials are being used right now at the stricken Fukushima Daiichi nuclear plant to filter the radioactive ions from waste water, these materials also tend to absorb non-radioactive chlorine, magnesium and calcium.
Since both chlorine and magnesium ions occur naturally in seawater (used to cool down the nuclear reactors in the aftermath of the March 11th earthquake and tsunami), decontamination rates are noticeably slow and inefficient.
The researchers at NIMS state that their new silica-based material doesn't get clogged with non-radioactive ions, thus allowing workers to decontaminate more water in a shorter period of time.
Tests conducted by the NIMS team show promising results: one gram of the silica material can absorb 20 milligrams of radioiodine or 13 milligrams of strontium.
Using another measuring “yardstick”, the silica material can absorb approximately 65 billion becquerels worth of strontium 90, a highly toxic isotope of the element strontium which is produced in nuclear reactors and is found in fallout created by uranium- and plutonium-based atomic bombs.
The silica material has another desirable characteristic: it's cheap and uncomplicated to produce! “If factory-made, you can create tons of this material a day, and even at the laboratory level it costs just 60-70 yen per gram to make,” explained Sherif El Safty (right), project Chief Engineer at NIMS.
Not that Japanese authorities are looking for a cheap fix to the problem of lingering radioactivity from Fukushima, but at this point ANY improved remedy is well worth pursuing. (via Mainichi Daily News, top image via WGBH)