Distribution of iron forms and their correlations analysis with phosphorus forms in the sedimentary profiles of Taihu Lake.
YANG Wen-bin1, TANG Hao1,2, HAN Chao2, DING Shi-ming2
1. College of Environmental Science and Engineering, Anhui Normal University, Wuhu 241003, China;
2. State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
Occureneces and distributions of iron forms in the sediment cores from three typically zones of Lake Taihu, i.e. phytoplankton dominated zone, macrophyte dominated zone, and phytoplankton-macrophyte transition zone, were investigated using the sequential extraction procedure. Generally, the total iron contents decreased in the order:phytoplankton dominated zone(31.57±8.51mg/g) >phytoplankton-macrophyte transition zone(30.34±11.97mg/g) >macrophyte dominated zone(25.25±4.59mg/g), while the contents of different iron forms in the interest sites followed the variations:reducible oxides Feox2 >carbonate associated Fe Fecarb >easilyreducible oxidesFeox1 >poorly reactive sheet silicate FeFeprs >magnetite Femag >Absorbed Fe(Ⅱ), Fecarb、Feox1、Feox2 weremeasured to be7.79mg/g, 6.16mg/g, 8.18mg/g, accounting for 28.56%, 21.54%, 29.53% of total iron respectively, suggesting those highly reactive iron Fe(Ⅲ) were the dominated iron forms. The concents of different extracted phosphorus in sediment decreased in the order:NH2OH·HCl-P >MgCl2-P >NaAc-P >Na2S2O4-P >Concentrated HCl-P >(NH4)2C2O4-P. Three dominated phosphorus fractions including MgCl2-P、NaAc-P、NH2OH·HCl-Pwere measured to be 0.067mg/g, 0.061mg/g, 0.068mg/g, accounting for 35.28%、31.97% and 22.55% of the total extracted phosphorus.Significantly positive relationships were observed between the extracted phosphorus and iron fractions using the sequential extraction(P<0.05), further confirming the concomitant release of phosphorus from reduction dissolution ofFe(oxyhydr) oxides in sediments.
杨文斌, 唐皓, 韩超, 丁士明. 太湖沉积物铁形态分布特征及磷铁相关性分析[J]. 中国环境科学, 2016, 36(4): 1145-1156.
YANG Wen-bin, TANG Hao, HAN Chao, DING Shi-ming. Distribution of iron forms and their correlations analysis with phosphorus forms in the sedimentary profiles of Taihu Lake.. CHINA ENVIRONMENTAL SCIENCECE, 2016, 36(4): 1145-1156.
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