RAPID: Microbial cycling of Iron and Sulfur in Spring Creek Reservoir, Iron Mountain Mine

RAPID：铁山矿 Spring Creek 水库中铁和硫的微生物循环

• 批准号: 1855241
• 负责人: Dawn Sumner
• 金额: $ 7.33万
• 依托单位: University of California-Davis
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1855241&HistoricalAwards=false
• 关键词: RAPID; Microbial; cycling; Iron; Sulfur

In July 2018, the Carr Fire burned nearly 230,000 acres, including the area surrounding the Iron Mountain Superfund Site where mine-impacted drainage is diverted into the Spring Creek Reservoir. Microbes alter the water and sediment chemistry in the reservoir and change the quality of the water flowing downstream. This year, rain falling on the burn scar during the wet season is expected to cause rapid erosion and deposit extra sediment into the lake. This project will investigate how contaminated sediments are deposited in the lakes, and how microbes transform sediment, pore water, and reservoir water. Project personnel will examine inflowing sediments, microbial communities from the sediment, as well as water quality in the reservoir following storm events in the 2018/2019 season. Results will show how microbial activity changes sediment chemistry and water quality in the Spring Creek Reservoir and provide insights into similar burned over areas and mine-impacted soils. Mining activities in the Western USA has resulted in thousands of miles of streams impacted by acid mine discharge, and widespread contamination of soils by mine and smelter operations. Discharge of contaminated water and sediment from the Iron Mountain mine has historically impacted the upper Sacramento River, an important drinking water source and salmon spawning stream. The results of this project will help mine managers, local and regional environmental planners and reservoir managers understand the movement and fate of remobilized sediments, and to plan for the effects of wildfire on the vegetation and reclamation infrastructure that help to stabilize contaminated soils. The Iron Mountain Superfund Site contains the remnants of several abandoned mines, and Spring Creek drains part of this area with the Spring Creek Debris Dam and reservoir (SCR) capturing discharge before it enters the Keswick Reservoir and Sacramento River. In July 2018, the Carr Fire burned most of the Spring Creek watershed, and thus, sedimentation is expected to be high during the 2018/19 rainy season. The influx of sediment provides an opportunity to investigate how microbial communities colonize and transform sediment and pore waters in an acid mine drainage-influenced lake. Prior research in the SCR suggests that microbial communities reduce iron and sulfate in pore waters during high reservoir levels, and that iron and sulfide oxidize when water levels are low, producing acidity and mobilizing metals. The proposed research will characterize sediment influx, how microbial communities develop within the new sediment, and how microbial activity changes pore water chemistry. The research team will sample and analyze the sediments and pore and surface water 8 times from November 2018 to 2019. Analyses will include mineralogy; iron, sulfur, oxygen, and pH of the water; and molecular analyses of the microbial communities. This research will provide fundamental insights into environmental biogeochemistry in acid mine drainage-contaminated environments and provide guidance for managing the water quality in the SCR.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

2018 年 7 月，卡尔大火烧毁了近 230,000 英亩土地，其中包括铁山超级基金遗址周围的地区，那里受地雷影响的排水被转移到斯普林溪水库。微生物改变水库中的水和沉积物化学成分，并改变下游流水的质量。今年，雨季落在烧伤疤痕上的雨水预计会导致快速侵蚀，并将额外的沉积物沉积到湖中。该项目将研究受污染的沉积物如何沉积在湖泊中，以及微生物如何转化沉积物、孔隙水和水库水。项目人员将检查流入的沉积物、沉积物中的微生物群落以及 2018/2019 年风暴事件后水库的水质。结果将显示微生物活动如何改变 Spring Creek 水库的沉积物化学和水质，并提供对类似烧毁地区和受地雷影响的土壤的见解。美国西部的采矿活动导致数千英里的溪流受到酸性矿山排放的影响，以及采矿和冶炼作业对土壤的广泛污染。 铁山矿井排放的受污染水和沉积物历来影响着萨克拉门托河上游，萨克拉门托河是重要的饮用水源和鲑鱼产卵溪流。该项目的结果将帮助矿山管理者、地方和区域环境规划者以及水库管理者了解重新流动的沉积物的运动和命运，并规划野火对有助于稳定受污染土壤的植被和复垦基础设施的影响。 铁山超级基金场地包含几个废弃矿井的残余物，斯普林溪在进入凯西克水库和萨克拉门托河之前通过斯普林溪碎片坝和水库 (SCR) 捕获排放物，排出该地区的部分水。 2018 年 7 月，卡尔大火烧毁了 Spring Creek 流域的大部分地区，因此预计 2018/19 雨季的沉积量会很高。沉积物的流入为研究微生物群落如何在受酸性矿井排水影响的湖泊中定植和转化沉积物和孔隙水提供了机会。先前对 SCR 的研究表明，在水库水位较高时，微生物群落会减少孔隙水中的铁和硫酸盐，而在水位较低时，铁和硫化物会氧化，产生酸度并移动金属。 拟议的研究将描述沉积物流入、微生物群落如何在新沉积物中发育以及微生物活动如何改变孔隙水化学。研究小组将于2018年11月至2019年期间对沉积物、孔隙和地表水进行8次取样和分析。分析内容包括矿物学；铁、硫、氧和水的 pH 值；和微生物群落的分子分析。这项研究将为酸性矿山排水污染环境中的环境生物地球化学提供基本见解，并为 SCR 中的水质管理提供指导。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力优势和更广泛的评估进行评估，被认为值得支持。影响审查标准。