Phosphorus release from coastal sediments: Impacts of the oxidation-reduction potential and sulfide.
The release of phosphorus (P) from benthic sediments can affect the P content, nutrient status and quality of overlying waters in coastal ecosystem. This study was carried out to investigate the influence of oxidation-reduction potential (ORP) and sulfide on P release from sediments in the coastal estuary of the Yuniao River, China. The results showed that ferric iron-bound P was the main P burial phase in the sediments. The P concentration in overlying water increased with ORP decrease and sulfide increase, displaying a significant linear correlation with the ORP and sulfide concentration. The results indicate that decreased ORP may elevate the zero equilibrium phosphorus concentration, enhancing the capability of P release. And increased sulfide may react or capture reactive iron in sediments, reducing the P adsorption capacity and accelerating P release. Therefore, the control of ORP and sulfide production is important in the sink/source conversion of P in coastal sediments.
Research Center for Coastal Environment Engineering Technology of Shandong Province, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, China.
Zhaoran
Z
Li
Research Center for Coastal Environment Engineering Technology of Shandong Province, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, China. Electronic address: yqsheng@yic.ac.cn.
Yanqing
Y
Sheng
Research Center for Coastal Environment Engineering Technology of Shandong Province, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, China.
Jian
J
Yang
Southern Cross GeoScience, Southern Cross University, Lismore, New South Wales 2480, Australia.
Edward D
ED
Burton
D000327:Adsorption; D002681:China; D017753:Ecosystem; D063366:Estuaries; D019015:Geologic Sediments / Q000737:chemistry*; D007501:Iron / Q000737:chemistry; D010084:Oxidation-Reduction; D010758:Phosphorus / Q000032:analysis* / Q000737:chemistry; D045483:Rivers / Q000737:chemistry*; D013440:Sulfides / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry
D013440:Sulfides; D014874:Water Pollutants, Chemical; D010758:Phosphorus; D007501:Iron
Coastal river; Oxidation-reduction potential; Phosphorus; Sediments; Sulfur