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Measuring Phosphorus Release in Laboratory Microcosms for Water Quality Assessment
Published on: July 22, 2019
Phosphorus sorption capacities in a headstream landscape--the pond chain structure
Qiang Fu1, Cheng-qing Yin, Bao-qing Shan
1State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
Journal of Environmental Sciences (China)
|February 7, 2007
Summary
Phosphorus sorption capacity in wetland sediments varies with landscape position and depth. Oxalate-extractable iron (Feox) is the key factor controlling this capacity in pond chain structures.
Area of Science:
- Environmental Science
- Soil Science
- Hydrology
Background:
- Phosphorus (P) output from headstream watersheds is a critical environmental concern.
- Pond chain structures (PCS) are common in agricultural watersheds, influencing P dynamics.
- Understanding P sorption in wetland sediments is vital for watershed management.
Purpose of the Study:
- To investigate phosphorus sorption characteristics in pond surface sediments within a PCS.
- To determine the influence of landscape position and sediment depth on P sorption.
- To identify key sediment properties controlling P sorption capacity.
Main Methods:
- Analysis of P sorption capacities (P sorption index, PSI) in pond sediments (0-12 cm depth).
- Assessment of sediment physico-chemical properties (pH, Feox, TOC, Ca, Mg) along a PCS gradient.
- Correlation analysis to identify factors controlling PSI.
Main Results:
- P sorption capacities exhibited significant gradient variability with landscape position and sediment depth.
- Higher elevation ponds demonstrated greater P sorption capacities.
- Oxalate-extractable iron (Feox) was strongly positively correlated with PSI (r=0.92, p<0.001), identified as the key controlling factor.
Conclusions:
- Spatial variations in P sorption capacity exist within PCS, influenced by factors like Feox.
- Long-term inputs affect sediment constituents and P sorption.
- Utilizing spatial differences in sorption capacity is crucial for managing nonpoint source P pollution.
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