Microbial Fe(II) oxidation and heavy metal co-precipitation in the Rio Tinto region, Spain

西班牙力拓地区的微生物 Fe(II) 氧化和重金属共沉淀

• 批准号: 329562988
• 负责人: Professor Dr. Andreas Kappler
• 金额: --
• 依托单位: Arbeitsgruppe Geomikrobiologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/329562988?language=en
• 关键词: Microbial; Fe; II; oxidation; heavy

Pollution of aquatic environments by heavy metals (HMs) has long been considered a major threat to living organisms that are in contact with contaminated water. Acid mine drainage (AMD) forming in mining regions often discharges substantial loads of HMs into local rivers, which then become contaminated with toxic metals. The Rio Tinto river region in the province of Huelva, Spain, is of great interest as it is considered to be one of the most polluted fluvial-estuarine systems in the world. The Rio Tinto basin is divided into two three zones based on topological, geological and geochemical characteristics: the northern region characterized by stable hydrogeochemical parameters with a mean pH of 2.3 and high concentrations of Fe in solution, the estuary with a daily pH gradient in the range of 2.5-6.8 and the transitional zone. Despite acidic pH and high HM content, the Rio Tinto is characterized by a high level of microbial Fe(II)-oxidizing activity that can stimulate Fe(III) precipitation and thus accelerate the process of HM retardation by co-precipitation with or by sorption onto Fe(III) minerals. The first goal of the present proposal is to determine the influence of the spatial and temporal pH fluctuations on the abundance and the activity of Fe(II)-oxidizing microorganisms and to evaluate if and how pH fluctuations stimulate or supress the activity of acidophilic Fe(II)-oxidizing microorganisms in the transitional zone. The second goal is to determine whether the pH dynamics in the transitional zone influence or even control the identity and composition of the primary minerals that are produced by abiotic and biotic Fe(II) oxidation. The third goal is to determine how the key biogeochemical processes (microbial and abiotic Fe(II) oxidation) and the composition of precipitated minerals control the fate and transport of HMs in the northern region and transitional zones. The results from this project will help us to understand changing patterns in HM mobility not only in the transitional zone of the Rio Tinto but also in other former mining areas contaminated with HMs.

重金属对水环境的污染一直被认为是与受污染水接触的生物体的主要威胁。在矿区形成的酸性矿井排水（AMD）经常将大量的HMs排入当地河流，然后被有毒金属污染。西班牙韦尔瓦省的里奥廷托河地区是世界上污染最严重的河流-河口系统之一，因此引起了极大的兴趣。根据拓扑、地质和地球化学特征，力拓盆地分为两个三个区：北方地区水文地球化学参数稳定，平均pH值为2.3，溶液中Fe浓度较高;河口地区，每日pH梯度在2.5-6.8之间;过渡区。尽管酸性pH值和高HM含量，力拓的特征在于高水平的微生物Fe（II）氧化活性，其可以刺激Fe（III）沉淀，从而通过与Fe（III）矿物共沉淀或通过吸附到Fe（III）矿物上来加速HM延迟的过程。本提案的第一个目标是确定的空间和时间的pH值波动的影响的丰度和活性的Fe（II）-氧化微生物和评估是否以及如何pH值波动刺激或抑制嗜酸性Fe（II）-氧化微生物的活性在过渡区。第二个目标是确定过渡区的pH动态是否影响甚至控制由非生物和生物Fe（II）氧化产生的原生矿物的身份和组成。第三个目标是确定关键的地球化学过程（微生物和非生物Fe（II）氧化）和沉淀矿物的组成如何控制HMs在北方地区和过渡带的命运和运输。该项目的结果将有助于我们了解HM流动性的变化模式，不仅在力拓的过渡区，而且在其他前矿区与HM污染。

项目成果

Role of biogenic Fe(III) minerals as a sink and carrier of heavy metals in the Rio Tinto, Spain.

• DOI: 10.1016/j.scitotenv.2020.137294
• 发表时间: 2020-02
• 期刊: The Science of the total environment
• 作者: S. Abramov;J. Tejada;Lars Grimm;Franziska Schädler;A. Bulaev;E. Tomaszewski;J. Byrne;D. Straub;H. Thorwarth;R. Amils;S. Kleindienst;A. Kappler