Methane fluxes of freshwater sediments in relation to temperature and salt stress
- Georgia State Univ., Atlanta, GA (United States)
Dynamics of methane fluxes of freshwater sediments in response to temperature changes and saline stress were investigated with a set of laboratory sediment microcosms. Sediments actively evolved methane over a temperature range of 0{degrees} to 45{degrees}C. Arrhenius plots were biphasic with a break point at approximately 25{degrees}C. {open_quotes}Ea{close_quotes} values were 101.8 {+-} (13.6) and 61.7 {+-} (11.4) kJ mol{sup -1} above and below 25{degrees}C, respectively. Temperature coefficients (Q10 values) show an approximate 9-fold increase of the CH{sub 4} emission rate for the 10{degrees}C rise in temperature over the range of 25{degrees} to 35{degrees}C. Methane fluxes were measured within 2 hours of saline intrusion of NaCI (0.05 or 0.15 M). The initial response to 0.15M NaCI addition was an episodic methane flux that ranged from 3. 1 to 14.2 ng microcosms{sup -1} min{sup -1} in the form of a pulse of < 2h interval. Measurements of CH{sub 4} fluxes on day 28 after saline intrusion revealed sink capacities that ranged between -0.45 and - 0.54 ng microcosm{sup -1} min{sup -1}.
- OSTI ID:
- 518642
- Report Number(s):
- CONF-9704106-; ISSN 0147-9369; TRN: 97:003464-0002
- Journal Information:
- Georgia Journal of Science, Vol. 55, Issue 1; Conference: 74. annual meeting of the Georgia Academy of Science, Carrollton, GA (United States), 25-26 Apr 1997; Other Information: PBD: 1997
- Country of Publication:
- United States
- Language:
- English
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