Impacts of Acid Mine Drainage on Dissolved Inorganic Carbon Cycling in Receiving Streams

05-10954 Atekwana.河流是陆地碳转化及其向大气或海洋库转移的重要环节。酸性矿山废水对河流中溶解无机碳库的扰动对生物活动、化学反应和碳动力学有重要影响。该项目将调查AMD影响流域的假设，作为一个“化学泵”转换和转移碳从陆地水库到大气水库。受AMD影响的流域中的碳酸盐缓冲反应可能将储存在陆地水库中的大量碳转化为溶液，随着酸性矿山废水排入河流，这些溶液会流失到大气中。鉴于美国和全球范围内有超过557，650个废弃矿场，AMD影响的流域可能成为长期大气中二氧化碳的重要来源，从而增加大气碳预算。将通过评估DIC从受AMD影响的地下水到溪流的通量、溪流内DIC的演变、溪流DIC与大气CO2之间的交换以及受影响流域的溪流DIC的输出来研究受AMD影响的溪流中的碳循环。将通过开展实地和实验室研究来实现项目目标，以便：1）记录DIC的空间和时间模式、DIC的同位素比、主要离子和AMD影响的地下水和溪流中的金属，2）确定控制AMD影响的溪流中DIC的分布、浓度和同位素比的重要物理和地球化学过程，和3）开发一个模型，捕捉的过程和控制的碳循环在AMD影响流的动态相互作用。受AMD影响的流域的碳循环研究是人类强迫导致的更大的全球变化问题的重要组成部分。因此，拟议的研究预计将提供一个框架，了解在AMD影响流域的碳通量，这是至关重要的评估人为强迫流域尺度碳动态。这项研究将使我们能够确定AMD影响流域和大气之间的CO2转移和交换的重要控制。作为更广泛的影响组成部分的一部分，两名学生（一名少数民族研究生和一名本科生）将在这个项目中接受指导和培训。与拟议项目相关的实地取样将构成PI教授的含水地球化学和稳定同位素地质学课程的实地和实验室实践的基础。PI还将参与其他本科生作为密苏里州罗拉大学（UMR）本科生研究经验（OURE）计划的一部分。具有地球科学偏好的UMR夏季杰克林研究所的高年级和初中学生也将参与该项目的实地和实验室部分。研究结果将在地球科学会议和同行审查出版物中传播

05-10954 Atekwana... Streams represent an important link in the conversion of terrestrial carbon and its transfer to the atmospheric or oceanic reservoir. Perturbation of dissolved inorganic carbon (DIC) pool in streams by acid mine drainage (AMD) has important consequences for biological activities, chemical reactions, and carbon dynamics. This project will investigate the hypothesis that AMD impacted watersheds act as a "chemical pump" converting and transferring carbon from terrestrial reservoirs to the atmospheric reservoir. Carbonate buffering reactions in AMD impacted watersheds potentially convert large amounts of carbon stored in the terrestrial reservoir into solution, which is lost to the atmosphere as acid mine drainage is discharged to streams. Given the more than 557,650 abandoned mine sites in the United States, and more globally, AMD impacted watersheds may serve as a significant source of CO2 to the atmosphere in the long term, and thus increasing the atmospheric carbon budget. Carbon cycling in AMD impacted streams will be investigated by assessing DIC flux from AMD impacted groundwater to streams, the evolution of DIC within the streams, the exchange between stream water DIC and atmospheric CO2, and export of stream water DIC from impacted watersheds. The project objectives will be achieved by conducting field and laboratory studies to: 1) document the spatial and temporal patterns of DIC, isotope ratio of DIC, major ions, and metals in AMD impacted groundwater and stream water, 2) determine the important physical and biogeochemical processes controlling the distribution, concentration, and isotope ratio of DIC in AMD impacted stream water, and 3) develop a model that captures the dynamic interaction of the processes and controls on carbon cycling in AMD impacted streams. Research on carbon cycling in AMD impacted watersheds is an important component of the larger global change question resulting from anthropogenic forcing. Thus, the proposed research is expected to provide a framework for understanding carbon fluxes in AMD impacted watersheds, which is critical for assessing anthropogenic forcing on watershed-scale carbon dynamics. This study will allow us to determine important controls on the transfer and exchange of CO2 between AMD impacted watershed and the atmosphere. As part of the broader impact components, two students (a minority graduate and an undergraduate student) will be mentored and trained in this project. Field sampling related to the proposed project will form the basis of hands-on field and laboratory exercises in aqueous geochemistry and stable isotope geology courses taught by the PI. The PI will also engage other undergraduates as part of University of Missouri Rolla (UMR) Opportunities for Undergraduate Research Experience (OURE) program. Seniors and junior high school students in the UMRs summer Jackling Institute with a geosciences preference will also be engaged in the field and laboratory component of this project. The results of the study will be disseminated at geoscience conferences and in peer review publications