The solubility and behavior of iron (Fe) in natural waters is tightly linked to Fe speciation, and Fe speciation likely influences how Fe distributes between the water column and sediments. In this study, the function of a lake as an Fe sink, with focus on the role of Fe speciation, was assessed for Lake Bolmen in southern Sweden. We found that a large fraction of the Fe flowing in to the lake was efficiently lost by sedimentation in the lake basin. Fe in inflowing water was a mix of organically complexed mononuclear Fe, Fe-(oxy)hydroxides and Fe-bearing clays, while surface sediments were composed of Fe-(oxy)hydroxides, Fe-bearing clays, Fe-bearing silicates and Fe sulfides. The absence of organically complexed Fe in the surface sediments indicates that the lake is mainly a sink for minerogenic fractions. Furthermore, while lakes are considered to be sinks of Fe, it has been suggested that this function may be impaired by increasing precipitation and consequently shorter water residence time. In this study there were large within- and between-year variations in precipitation and Fe concentrations. However, rather than smaller Fe losses to the sediments during wet years, within-lake losses tended to be larger due to higher loading of Fe from the catchment. Thus, forecasted increases in precipitation may result in enhanced catchment export and Fe loading to lakes, and subsequently enhanced Fe sequestration in sediments.

铁 (Fe) 在天然水中的溶解度和行为与 Fe 的形态密切相关，而 Fe 的形态可能会影响 Fe 在水柱和沉积物之间的分布。在这项研究中，对瑞典南部博尔门湖的湖泊作为铁汇的功能进行了评估，重点是铁物种形成的作用。我们发现流入湖中的大部分 Fe 被湖盆中的沉积有效地损失了。流入水中的铁是有机络合的单核铁、铁（氧）氢氧化物和含铁粘土的混合物，而表层沉积物由铁（氧）氢氧化物、含铁粘土、含铁硅酸盐和铁硫化物组成. 表层沉积物中不存在有机络合的 Fe 表明该湖主要是成矿部分的汇。此外，虽然湖泊被认为是铁的汇，但有人认为，这种功能可能会因降水增加和水停留时间缩短而受到损害。在这项研究中，降水量和 Fe 浓度在年内和年间变化很大。然而，在潮湿的年份，沉积物的铁损失不是较小，而是由于流域中铁的负载较高，湖内损失往往更大。因此，预测的降水量增加可能会导致集水区出口增加和向湖泊中的铁负荷增加，从而增强沉积物中的铁固存。在这项研究中，降水量和 Fe 浓度在年内和年间变化很大。然而，在潮湿的年份，沉积物的铁损失不是较小，而是由于流域中铁的负载较高，湖内损失往往更大。因此，预测的降水量增加可能会导致集水区出口增加和向湖泊中的铁负荷增加，从而增强沉积物中的铁固存。在这项研究中，降水量和 Fe 浓度在年内和年间变化很大。然而，在潮湿的年份，沉积物的铁损失不是较小，而是由于流域中铁的负载较高，湖内损失往往更大。因此，预测的降水量增加可能会导致集水区出口增加和向湖泊中的铁负荷增加，从而增强沉积物中的铁固存。