Determination of iron speciation in lake and its effects through iron availability on algal blooming

湖中铁形态的测定及其铁可用性对藻类繁殖的影响

基本信息

批准号：
17310013
负责人：
IMAI Akio
金额：
$ 10.07万
依托单位：
National Institute for Environmental Studies
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2005
资助国家：
日本
起止时间：
2005 至 2007
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-17310013/
关键词：
Iron Lake peciation Algal bloom Dissolved organic matter River Cyanobacteria Aquauatic humic substances 錯化ボルタンメトリー AGP

项目摘要

Analytical methods were developed to determine the concentration of total dissolved iron and its chemical speciation in freshwater using cathodic stripping voltammetry (CSV) with 1-nitroso-2-naphthol (NN) at pH 8.1.The horizontal distribution and temporal variation of dissolved iron and its chemical speciation in Lake Kasumigaura and its inflowing rivers were investigated. Concentrations of dissolved iron and its organic ligands clearly decreased as lake water flowed from the river entry points toward the center of the lake, indicating their riverine origin. The fraction of iron occurring in organic complexes tended to increase with the water -flow. Most of the dissolved iron was present as organic complexes (882% 99.9%).Effects of iron complexation with DOM on algal growth in the eutrophic Lake Kasumigaura were assessed using 2 species of cyanobacteria, Microcystis aeruginosa and Planktothrix agardhii, by combining the algal growth potential (AGP) test and pretreatment of DOM decomposition by UV irradiation. Iron limited the 2 species, as did nitrogen and phosphorus in Lake Kasumigaura. Moreover, the growth of the 2 species was inhibited by iron complexation with DOM.The growth characteristics of two species of cyanobacteria, Microcystis aeruginosa and Planktothrix agardhii, in iron-limited continuous cultures were investigated. The relationships between dissolved iron concentration, cell quota of iron, and population growth rate were determined applying two equations, Monod's and Droop's equations. A kinetic model under iron limitation was developed based on the growth characteristics determined in this study. The model simulation suggested that Microcystis is a superior competitor under iron limitation.

开发了使用 1-亚硝基-2-萘酚 (NN) 在 pH 8.1 下使用阴极溶出伏安法 (CSV) 测定淡水中总溶解铁浓度及其化学形态的分析方法。溶解铁和溶解铁的水平分布和时间变化对其在霞浦湖及其流入河流中的化学形态进行了调查。当湖水从河流入口流向湖中心时，溶解铁及其有机配体的浓度明显降低，这表明它们起源于河流。有机络合物中铁的比例随着水流的增加而增加。大多数溶解的铁以有机复合物的形式存在（882% 99.9%）。通过结合藻类生长，使用 2 种蓝藻（铜绿微囊藻和 Planktothrix agardhii）评估了铁与 DOM 络合对富营养化霞浦湖中藻类生长的影响。紫外辐照下DOM分解的电位（AGP）测试和预处理。铁限制了这两种物种，霞浦湖中的氮和磷也是如此。此外，铁与DOM的络合抑制了这2个物种的生长。研究了铜绿微囊藻和Planktothrix agardhii这两个蓝藻在限铁连续培养物中的生长特性。应用两个方程（莫诺方程和德鲁普方程）确定溶解铁浓度、细胞铁配额和种群增长率之间的关系。根据本研究确定的生长特征，开发了铁限制下的动力学模型。模型模拟表明，在铁限制下，微囊藻是一个优越的竞争者。