Environmental radioactivity, mainly in the Tohoku and Kanto areas, due
to the long living radioisotopes of Cesium is laying obstacle on speedy
recovery from the impacts of Fukushima Daiichi Nuclear Power Plant
accident. Though incineration of the contaminated wastes is encouraged,
safe disposal of Cesium enriched ashes is the big challenge. In order to
address this issue, safe incineration of contaminated wastes while
restricting the release of volatile Cesium to the atmosphere was
studied.
Detail study on effective removal of Cesium from ash samples generated from wood bark, household garbage and municipal sewage sludge was performed. For wood ash and garbage ash, washing only with water at ambient conditions removed radioactivity due to 134Cs and 137Cs, retaining most of the components other than the alkali metals with the residue. However, removing Cesium from sludge ash needed acid treatment at high temperature. This difference in Cesium solubility is due to the presence of soil particle originated clay minerals in the sludge ash. Because only removing the contaminated vegetation is found to sharply decrease the environmental radioactivity, volume reduction of contaminated biomass by incineration makes great sense.
In addition, long term need of leachate monitoring system in the landfill can be avoided by washing the ash with water. Once the Cesium in solids is extracted to the solution, it can be loaded to Cesium selective adsorbents like Prussian blue and safely stored in a small volume.
Abstract of the paper by Durga Parajuli , Hisashi Tanaka , Yukiya Hakuta , Kimitaka Minami , Tohru Kawamoto , and Shigeharu Fukuda
March 13, 2013
http://pubs.acs.org/doi/pdf/10.1021/es303467n
Detail study on effective removal of Cesium from ash samples generated from wood bark, household garbage and municipal sewage sludge was performed. For wood ash and garbage ash, washing only with water at ambient conditions removed radioactivity due to 134Cs and 137Cs, retaining most of the components other than the alkali metals with the residue. However, removing Cesium from sludge ash needed acid treatment at high temperature. This difference in Cesium solubility is due to the presence of soil particle originated clay minerals in the sludge ash. Because only removing the contaminated vegetation is found to sharply decrease the environmental radioactivity, volume reduction of contaminated biomass by incineration makes great sense.
In addition, long term need of leachate monitoring system in the landfill can be avoided by washing the ash with water. Once the Cesium in solids is extracted to the solution, it can be loaded to Cesium selective adsorbents like Prussian blue and safely stored in a small volume.
Abstract of the paper by Durga Parajuli , Hisashi Tanaka , Yukiya Hakuta , Kimitaka Minami , Tohru Kawamoto , and Shigeharu Fukuda
March 13, 2013
http://pubs.acs.org/doi/pdf/10.1021/es303467n
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