ccording to a story in the Mainichi Daily News, a Japanese research group using a newly discovered algae, called “Parachlorella sp. binos” or “binos” for short, has demonstrated its performance as better at absorbing some radioactive materials than is zeolite, which is being used at the Fukushima No. 1 Nuclear Power Plant to treat radioactively contaminated water.
Binos has already been commercialized by Japan Biomass Corp., a University of Tsukuba-affiliated startup, for the cleaning of sewage, and the corporation conducted joint research with the Kitasato Institute and other groups to explore applying binos to cleaning radioactively-contaminated water as well.
Researcher Hiroki Shimura of the University of Yamanashi’s medical department agreed to help with the research and conducted tests with the algae on radioactively contaminated water collected from ditches in Namie, Fukushima Prefecture, from April through July.
He put 100 grams of binos each into one-liter samples of contaminated water, one with two megabecquerels of radioactive cesium-137, one with two megabecquerels of radioactive strontium, and one with three megabecquerels of radioactive iodine. After 10 minutes, the strontium was around 80 percent removed and the cesium-137 was around 40 percent removed. After 24 hours, the iodine was about 40 percent removed.
By contrast, zeolite did not absorb iodine at all. After about one hour, zeolite absorbed only around 60 percent of the strontium in its mixture, compared with 95 percent absorbed by the binos algae.
Because binos is an alga, it can be easily grown where there is light and carbon dioxide. Researchers say that if dried, the weight of binos shrinks to 1/20, which could help simplify dealing with it after it has been used to absorb radioactive materials.
The researchers are talking with power plant equipment makers over introducing the algae to work at the Fukushima plant, and a demonstration of using the algae to treat radioactively contaminated soil and then storing the algae is planned in the city of Date, Fukushima Prefecture, at the end of October. The demonstration will be conducted by multiple corporations including Japan Biomass Corp.