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Exposure of soil constituents to elevated temperatures during wildfire can significantly affect their properties and consequently, increase the mobility of the bound contaminants. To estimate the potential of wildfires to influence metal remobilization from the burned soil due to the changes in cation exchange capacity (CEC) after organic matter combustion and mineral alteration and degradation, changes in soil properties after exposure to different temperatures was investigated. This was accomplished through analysis of geochemical, mineralogical and surface physicochemical properties of a soil sample exposed to different temperatures in a laboratory. Heating the soil sample at 200 °C, 500 °C and 850 °C resulted in an increase in pH (from 5.9 to 12.3), decrease in cation exchange capacity (from 47.2 to 7.3 cmol+kg−1) and changes in the specific surface area (observed only at 500 °C), that are associated with structural modifications of clay minerals and ferromagnetic minerals. Extraction analysis showed the increase in the concentration of almost all analysed elements (Al, Cd, Co, Cr, Fe, Mn and Zn) in soil eluates. The observed increase, following high– temperature heating (500 °C and 850 °C), was as much as 15 times higher (e.g., Al), compared to the native soil sample (25 °C). This strongly indicates that wildfire can act as a trigger for remobilization of heavy metals.
</abstract>

Exposure of soil constituents to elevated temperatures during wildfire can significantly affect their properties and consequently, increase the mobility of the bound contaminants. To estimate the potential of wildfires to influence metal remobilization from the burned soil due to the changes in cation exchange capacity (CEC) after organic matter combustion and mineral alteration and degradation, changes in soil properties after exposure to different temperatures was investigated. This was accomplished through analysis of geochemical, mineralogical and surface physicochemical properties of a soil sample exposed to different temperatures in a laboratory. Heating the soil sample at 200 °C, 500 °C and 850 °C resulted in an increase in pH (from 5.9 to 12.3), decrease in cation exchange capacity (from 47.2 to 7.3 cmol+kg−1) and changes in the specific surface area (observed only at 500 °C), that are associated with structural modifications of clay minerals and ferromagnetic minerals. Extraction analysis showed the increase in the concentration of almost all analysed elements (Al, Cd, Co, Cr, Fe, Mn and Zn) in soil eluates. The observed increase, following high– temperature heating (500 °C and 850 °C), was as much as 15 times higher (e.g., Al), compared to the native soil sample (25 °C). This strongly indicates that wildfire can act as a trigger for remobilization of heavy metals.

Heat–induced changes in soil properties: fires as cause for remobilization of chemical elements

Department of Geology, Faculty of Science

Department of Chemistry, Faculty of Science

Journal of Hydrology and Hydromechanics

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Exposure of soil constituents to elevated temperatures during wildfire can significantly affect their properties and consequently, increase the mobility of the...

Heat–induced changes in soil properties: fires as cause for remobilization of chemical elements

Published Online: Nov 16, 2022

Page range: 421 - 431

Received: May 07, 2022

Accepted: Jul 09, 2022

DOI: https://doi.org/10.2478/johh-2022-0024

Keywords
Heating, Soil, Trace metals, Physicochemical properties

© 2022 Hana Fajković et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Heat–induced changes in soil properties: fires as cause for remobilization of chemical elements

Published Online: Nov 16, 2022

Page range: 421 - 431

Received: May 07, 2022

Accepted: Jul 09, 2022

DOI: https://doi.org/10.2478/johh-2022-0024

KeywordsHeating, Soil, Trace metals, Physicochemical properties

© 2022 Hana Fajković et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Keywords
Heating, Soil, Trace metals, Physicochemical properties