Phosphorus speciation in the sediment profile of Lake Erhai, southwestern China: Fractionation and ^(31)P NMR

作     者：Runyu Zhang Liying Wang Fengchang Wu Baoan Song 

作者机构：State Key Laboratory of Environmental GeochemistryInstitute of GeochemistryChinese Academy of Sciences State Environmental Protection Key Laboratory for Lake Pollution ControlChinese Research Academy of Environmental Sciences Key Laboratory of Green Pesticide and Agricultural BioengineeringMinistry of Education 

出 版 物：《Journal of Environmental Sciences》 (环境科学学报（英文版）)

年 卷 期：2013年第25卷第6期

页      面：1124-1130页

核心收录：

学科分类：0830[工学-环境科学与工程（可授工学、理学、农学学位）] 070902[理学-地球化学] 0709[理学-地质学] 07[理学] 08[工学] 0815[工学-水利工程] 

基　　金：supported by the National Natural Science Foundation of China (No. 40903052,41273151) the National Basic Research Program (973) of China (No.2008CB418006) the opening foundation of Guizhou University (No. 2009GDGP0105) 

主　　题：phosphorus speciation fractionation 31p NMR sediment eutrophication 

摘      要：The distribution characteristics of phosphorus （P） forms in the sediment profile of Lake Erhai, in southwestern China has been investigated by sequential extraction and 31p nuclear magnetic resonance spectroscopy （NMR） of NaOH extracts to understand P dynamics and its potential contribution to lake eutrophication. Contents of P fractions varied in the order of NH4C1 extracted P （NH4C1- P） 〈 bicarbonate-dithionite extracted P （BD-P） 〈 HC1-P, Residual-P 〈 NaOH extracted P （NaOH-P）. The highly available NH4C1-P represented less than 1% of total P （TP）. BD-P and NaOH extracted reactive P （NaOH-rP） averaged 39%, while the ratio of Fe/P was higher than 15, indicating low P release from the sediments under permanent oxic condition. The less bio-available HC1-P, NaOH extracted nonreactive P （NaOH-nrP） and residual-P contributed 61% of TP. Regression analysis revealed that BD-P, NaOH-rP and HC1-P were positively correlated with the contents of Fe and Mn, A1 and Fe, and Ca, respectively. The investigation of P compound groups in NaOH extracts by 31p NMR showed that ortho-P and monoester-P were the largest two constituents of the P pool, followed by diester-P, phosphonate and pyro-P. A comparison of vertical variations of P groups in the sediment profile suggested that these compounds were involved in the P recycling to different extents in Lake Erhai. In particular, the lake exhibits high potential for labile P release from the surface sediments, which should be taken into consideration even after the outsourced P runoff ceased.