Study on Carbonized Temperature Estimation of Charcoal Remained in Burnt Area in Namie Town, Fukushima, Japan
Abstract
In 2017, a wildfire occurred in mountainous forest of Namie Town, Fukushima Prefecture, Japan, where is designated as a difficult-to-return zone due to high radiation dose after the TEPCO's Fukushima Daiichi nuclear power plant accident. With the wildfire, changes of dynamics of radionuclide, especially 137Cs was concerned. In this study, we focused residual charcoal to estimate burning temperature of surface soil and litter because it affects the dissolution behavior of chemicals and radiocesium in soil and litter on the forest floor of the burnt area. Due to the wildfire, the surface litter layers were lost in some Japanese cedar, red pine, and oak forests in this area. We set up the single plot at each forest and collected the residual charcoals from burnt sites. In addition, we also set the unburnt control plot nearby burnt locations. To clarify the carbonized temperature of residual charcoal, thermal analysis by TG-DTA and infrared adsorption spectrum analysis by micro-FTIR were conducted for litters, artificially burnt litters, and residual charcoals. Based on the analysis, cellulose which has the pyrolysis initiation temperature of about 230 ℃ had already been lost. On the other hand, lignin was not completely pyrolyzed and remained in almost all residual charcoals. These results indicate that the carbonized temperature was relatively low. In future works, we aim to estimate carbonized temperature more accurately by analyzing the specific region of FTIR spectra of lignin more detail which should lead to clarify the differences in thermal decomposition state among the residual charcoals.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFMNH23E0890N
- Keywords:
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- 1616 Climate variability;
- GLOBAL CHANGEDE: 1920 Emerging informatics technologies;
- INFORMATICSDE: 4313 Extreme events;
- NATURAL HAZARDSDE: 4341 Early warning systems;
- NATURAL HAZARDS