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Experimental Study Assessing the Role of Sedimentary Organic Materials to Control the Redox State of Ground Materials to Control the Redox State of Groundwater: Consumption of Dissolved Oxygen by Humic Acid
Author(s) -
Haysahi Kenichiro,
Shibata Hideyuki,
Yui Mikazu,
Ohmoto Hiroshi
Publication year - 2001
Publication title -
resource geology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.597
H-Index - 43
eISSN - 1751-3928
pISSN - 1344-1698
DOI - 10.1111/j.1751-3928.2001.tb00080.x
Subject(s) - redox , humic acid , oxygen , chemistry , reaction rate constant , groundwater , reaction rate , inorganic chemistry , environmental chemistry , mineralogy , nuclear chemistry , geology , kinetics , catalysis , organic chemistry , fertilizer , physics , geotechnical engineering , quantum mechanics
A total of 189 runs were completed to determine the rate of dissolved oxygen consumption in water by the reaction humic acid at 25°, 45°, and 65°C. Glass vial bottles were used as reaction vessels, and humic aicd and pure water of different intitial O 2 concentration was loaded with humic acid/water weight of 0.008 and 0.009. Vials were opened periodically to measure O 2 concentrations. The pH of the solution fluctuated in the early stages of the experiments and gradually decreased to a constant value. Dissolved oxygen concentration decreased, for example, from initial value of 12 mg/l to 9 mg/l at 25°C, to 5 mg/l at 45°C, and to 2 mg/l at 65°C after the reaction of 500 hours. Analyses of rates suggest that the reaction is first order, and rate constants are 8.42 × 10 ‐9 at 25°C, 2.22 × 10 ‐8 at 45°C, and 1.28 × 10 ‐7 moles m ‐2 s ‐1 at 65°C.