Pedosphere 12(2): 157--164, 2002
ISSN 1002-0160/CN 32-1315/P
©2002 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Preliminary study on nitrogen and phosphorus releases from creek sediments in Shanghai suburbs |
| HU Xue-Feng1, GAO Xiao-Jiang2, CHEN Zhen-Lou3, XU Shi-Yuan3, SHEN Ming-Neng3, WANG Shao-Ping3 and HE Bao-Gen4 |
1 Department of Environmental Science and Engineering, Shanghai University, Shanghai 200072 (China);
2 Department of Environmental Science and Engineering, Fudan University, Shanghai 200433 (China);
3 Department of Geography, East China Normal University, Shanghai 200062 (China);
4 Department of Geography, Shanghai Teacher University, Shanghai 200234 (China) |
| ABSTRACT |
| A laboratory study was conducted to observe the release of nitrogen and phosphorus from the sedimentsunder both anaerobic and aerobic conditions. The samples used were five creek sediments and a fish-pondsediment (as a comparison) obtained from suburban Shanghai. High loads of nitrogen and phosphoruswere found in the creek sediments. Total nitrogen of the sediments ranged from 1.17 to 5.95 g kg-1; totalphosphorus from 608.63 to 2 033.95 mg kg-1. Making up more than 90% of the total nitrogen, organicnitrogen was the dominant nitrogen fraction in the sediments; where as inorganic phosphorus was the dominant phosphorus fraction, which made up more than 85 percent of the total phosphorus. Cabound phosphorus fraction dominated inorganic phosphorus, which occupied more than 50% of the total. A large amount of ammonium was released from the sediments under both aerobic and anaerobic conditions, and the anaerobic releases were slightly greater than the aerobic. In addition, ammonium contents in the aerobic waters decreased sharply after reaching the peaks because of strong nitrification, compared with the relatively maintained ammonium peaks in the anaerobic waters. Anaerobic phosphate releases were much greater than the aerobic and the released ortho-phosphate was mainly from Fe-bound phosphorus. Ammonium and ortho-phosphate releases from the sample of the dredged creek were the lowest, showing that creek dredging could effectively remove contaminants from the surface of sediments and weaken the release potentials of nitrogen and phosphorus. Ammonium and ortho-phosphate releases from the fish-pond sediment were greater than those from the creek sediments though its total nitrogen and phosphorus were not the highest, which was probably due to the larger amount of biologically degraded organic matter in the fish-pond sediment. |
| Key Words: anaerobic, aerobic, creek sediments, fish-pond sediment, nitrogen and phosphorus releases |
| Citation: Hu, X. F., Gao, X. J., Chen, Z. L., Xu, S. Y., Shen, M. N., Wang, S. P. and He, B. G. 2002. Preliminary study on nitrogen and phosphorus releases from creek sediments in Shanghai suburbs. Pedosphere. 12(2): 157-164. |
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