Iron oxide from a seasonally anoxic lake
Iron oxide from a seasonally anoxic lake
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来自季节性缺氧湖的氧化铁
DOI：
10.1016/0016-7037(81)90275-1
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发表时间：
1981
影响因子：
5
通讯作者：
D. Cooke
中科院分区：
文献类型：
--
作者：
E. Tipping;C. Woof;D. Cooke
在Esthwaite Water中，由Fe（II）氧化形成的氧化铁，在湖泊季节性热分层和深水缺氧期间，颗粒物为无定形颗粒，呈近似球形或椭球形，直径在0.05-0.5 μm之间。湖水中的铁含量为每升1011- 1012个粒子，相当于3毫克l− 1铁。与土壤沃茨中通过氧化机制形成的具有相似化学成分的氧化铁不同，颗粒似乎不是由小的初级颗粒组成。这可能是因为在湖中，它们形成缓慢，过饱和度低。所述颗粒含有30- 40重量%的Fe。由于污染，碳含量不确定，但在4- 18%的范围内。腐殖碳占总重量的至少4-7%。存在的其它主要元素是P、N、Mn、Si、S。Ca和Mg，它们之间占总重量的8%。颗粒带负电荷，可能是因为吸附了腐殖物质，还有磷酸盐和硅酸盐。它们的电泳迁移率-pH依赖性类似于添加到表面Esthwaite水样品中的合成氧化铁。计算的zeta电位为− 27 mV，这足以使湖泊条件下的絮凝缓慢。低絮凝率的部分原因是形成了一个明确的峰值颗粒铁在水柱的湖泊。
The ferric oxide formed by oxidation of Fe(II) in Esthwaite Water, U.K., during the lake's seasonal thermal stratification and deep-water anoxia consists of amorphous particles which are approximately spherical or ellipsoidal, with diameters in the range 0.05–0.5 μm. Concentrations in the lake are 1011–1012particles per litre, corresponding to 3 mg l−1Fe. Unlike iron oxides of similar chemical composition formed by oxidative mechanisms in soil-borne waters, the particles do not appear to be composed of small primary particles. This is possibly because in the lake they form slowly, at low supersaturation. The particles contain 30–40% by weight Fe. The carbon content is uncertain because of contamination but is in the range 4–18%. Humic carbon contributes at least 4–7% of the total weight. Other major elements present are P, N, Mn, Si, S. Ca and Mg, comprising between them up to 8% of the total weight.The particles are negatively charged probably because of adsorbed humic substances, and also phosphate and silicate. Their electrophoretic mobility-pH dependence is similar to those of synthetic iron oxides added to samples of surface Esthwaite Water. The calculated zeta potential is − 27 mV, which is sufficiently high to make flocculation slow under lake conditions. The low flocculation rate partially accounts for the formation of a well-defined peak of particulate iron in the water column of the lake.