Pedosphere 13(4): 323--330, 2003
ISSN 1002-0160/CN 32-1315/P
©2003 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Factors controlling deoxygenation of “floodwater” overlying an acid sulfate soil: Experimental modeling |
C. LIN1,3 , P. G. HASKINS2 and J. LIN1 |
1 Centre for Coastal Management, Southern Cross University, Lismore NSW 2480 (Australia). E-mail: cxlin@scau.edu.cn
2 NSW Department of Infrastructure, Planning and Natural Resources, Coffs Harbour NSW 2450 (Australia)
3 College of Resources and Environment, South China Agricultural University, Guangzhou 510642 (China) |
| ABSTRACT |
| An incubation experiment was conducted to simulate the effect of flooding on water deoxygenation in acid sulfate soil floodplain systems. The originally oxygenated "floodwater" could be deoxygenated immediately following "flooding" and it is likely that this was caused mainly by decomposition of organic debris from the inundated plants. Deoxygenation eventually led to the depletion of dissolved oxygen (DO) in the "floodwater" and it is highly possible that this resulted in the transformations of ferric Fe to ferrous Fe, sulfate to hydrogen sulfide, and organic nitrogen to ammonia (ammonification). The accumulation of these reduced substances allows the "floodwater" to develop DO-consuming capacity (DOCC). When the "floodwater" is mixed with the introduced oxygenated water, apart from the dilution effects, the reduced substances contained in the "floodwater" oxidize to further consume DO carried by the introduced water. However, it appears that the DO drop in the mixed water can only last for a few hours if no additional DO-depleted "floodwater" is added. Entry of atmospheric oxygen into the water can raise the DO level of the mixed water and lower water pH through the oxidation of the reduced substances. |
| Key Words: acid sulfate soils, deoxygenation, experimental modeling, flood, organic matter |
| Citation: Lin, C., Haskins, P. G. and Lin, J. 2003. Factors controlling deoxygenation of “floodwater” overlying an acid sulfate soil: Experimental modeling. Pedosphere. 13(4): 323-330. |
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