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Impacts of Water Level Regulation on Estuary Sediment PhosphorusStorage and Bioavailability
TANG Xian-qiang,WU Min
Journal of Changjiang River Scientific Research Institute ›› 2015, Vol. 32 ›› Issue (12) : 8-13.
PDF(1870 KB)
PDF(1870 KB)
Impacts of Water Level Regulation on Estuary Sediment PhosphorusStorage and Bioavailability
Continuously submerged and intermittently submerged sediments collected from Shendinghe River estuary of Danjiangkou reservoir,were employed to conduct the dynamic water level(WL) regulation experiments with 3 rates of change of water level (0 cm.d-1,3 cm.d-1 and 6 cm.d-1).The whole experiments lasted three WL regulating cycles (nearly four months) and each single cycle included four WL dynamic phases:decline,stable,ascend and re-stable.The results show that:WL regulation promotes OM loss of sediment and results in the increase of pH value.When compared with the data without WL regulated control,3 cm.d-1 and 6 cm.d-1 WL regulations lead to the increase of 185.56%-204.92%(continuously submerged sediments) and185.28%-228.76%(intermittently submerged sediments) in concentrations of amorphous iron oxides,respectively.Furthermore,after WL regulation, concentrations of exchangeable phosphorus (Ex-P),aluminum bounded phosphorus (Al-P),iron bounded phosphorus (Fe-P),calcium bounded phosphorus (Ca-P) and total phosphorus (TP) increase in intermittently submerged and continuously submerged sediments,whereas OM loss,occluded phosphorus (O-P) activation and transformation,greatly contribute to the decline of organic phosphorus (Org-P) and O-P in sediment.With respect to the activation of Org-P and O-P under WL regulation,both of the two phosphorus fractions should be categorized into bio-available phosphorus components.
phosphorus / sediment / water level regulation / physical and chemical properties / activation
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