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The response of humic substances to soil acidification and freezing
AbstractThe effects of freezing and acidification on humic substances (HS) of tundra, soddy podzolic, and grey forest soils have been studied in a laboratory experiment. Samples were acidified to decreased the initial pH of soil suspension by a 1 pH unit and were kept at +9 or −12°C for two months. HS were sequentially extracted by two cation exchange resins (fractions HS-1 and HS-2) in distilled water, followed by alkali (HS-3). HS functions, as well as humic and fulvic acids isolated from them, were examined by fluorescence spectroscopy in the emission, excitation, and synchronous-scan excitation modes. Electrophoretic mobilities and E4/E6 ratios of HS-1, 2, and three fractions were analysed. On the basis of CHA/CFA and E4/E6 ratios and electrophoretic and fluorescence behaviour, HS fractions from the same sample showed distinct differences while corresponding fractions of different origin displayed evident similarities. HS of soils studied differed in their response to acidification and freezing. HS of treated and untreated soils were distinguished by fraction composition, peak wavelength, and intensity of fluorescence in excitation and synchronous-scan excitation spectra.
The response of humic substances to soil acidification and freezing
AbstractThe effects of freezing and acidification on humic substances (HS) of tundra, soddy podzolic, and grey forest soils have been studied in a laboratory experiment. Samples were acidified to decreased the initial pH of soil suspension by a 1 pH unit and were kept at +9 or −12°C for two months. HS were sequentially extracted by two cation exchange resins (fractions HS-1 and HS-2) in distilled water, followed by alkali (HS-3). HS functions, as well as humic and fulvic acids isolated from them, were examined by fluorescence spectroscopy in the emission, excitation, and synchronous-scan excitation modes. Electrophoretic mobilities and E4/E6 ratios of HS-1, 2, and three fractions were analysed. On the basis of CHA/CFA and E4/E6 ratios and electrophoretic and fluorescence behaviour, HS fractions from the same sample showed distinct differences while corresponding fractions of different origin displayed evident similarities. HS of soils studied differed in their response to acidification and freezing. HS of treated and untreated soils were distinguished by fraction composition, peak wavelength, and intensity of fluorescence in excitation and synchronous-scan excitation spectra.
The response of humic substances to soil acidification and freezing
Shirshova, L.T. (author) / Khomutova, T.E. (author)
Environmental International ; 20 ; 405-410
1994-02-20
6 pages
Article (Journal)
Electronic Resource
English
The response of humic substances to soil acidification and freezing
| Online Contents | 1994
| Online Contents | 1994
HUMEX (humic lake acidification experiment): chemistry, hydrology, and meteorology
| Online Contents | 1994