Chromate removal as influenced by the structural changes of soil components upon carbonization at different temperatures
Journal
Environmental Pollution
Journal Volume
162
Pages
151-158
Date Issued
2012
Author(s)
Chen, K.Y.
Liu, J.C.
Chiang, P.N.
Kuan, W.H.
Tzou, Y.M.
Deng, Y.
Tseng, K.J.
Chen, C.C.
Wang, M.K.
Abstract
Surface fire could induce heat transferring into the soil, creating a carbonized environment, which may alter the chemical compositions of soil organic matters (SOM). In the study, a surface soil was carbonized at up to 600 °C with limited air to simulate soils experiencing a surface fire, and Cr(VI) removal on the carbonized soils was investigated. NMR and FTIR analyses demonstrated a remarkable change of SOM structures at 300-400 °C. TGA-MS spectra indicated that (e.g. C(2)H(4), CH(3)OH and C(3)H(8)) were the major components in the evolved gases from the pyrolyzed soil. A maximum amount of Cr(VI) removal (ca. 4 mg g(-1) soil) occurred for the 200 °C-carbonized soils, attributed mainly to a significant increase of Cr(VI) reduction by 0.1 M KCl extractable organic carbon (EOC) with abundant carboxylic groups. Nonetheless, the formation of aromatic C upon carbonization of the soil at >400 °C may be responsible for Cr(VI) reduction.
SDGs
Type
journal article