Mine waste characterization through integrated synchrotron and geomicrobiological approaches

采矿业是加拿大经济的重要组成部分，但它也给我们带来了重大的环境挑战，包括水和土壤污染，生物系统的破坏，以及大量有毒尾矿的积累。细菌可以在矿山废物管理中造成重大问题和重大利益：它们可以导致从岩石中释放有毒元素，如砷，反过来，它们可以控制和防止有毒元素释放到环境中。了解特定矿山废物中存在哪些细菌，以及随着时间的推移它们将如何影响废物中有毒元素的化学性质，这一点非常重要。更复杂的是，一些细菌可以创造微环境：细菌产生的化学条件与其他废物非常不同。这些微环境对有毒元素的整体化学稳定性有重要影响。有时，这些生态位中的细菌数量相对较少，即使使用专门的遗传工具也很难看到它们，但它们仍然可以对废物化学产生重大影响。因此，研究微生物产生的微环境是很重要的，因为它们可能对矿业公司如何负责任地管理其废物产生重大影响。为了应对这一研究挑战，我为我的学生计划了一个合作和跨学科的研究项目。我们的研究系统将是来自萨斯喀彻温省北部的铀矿尾矿和废石的微环境。我们将使用同步加速器成像方法来绘制样品中的元素和矿物质，并创建微生物如何控制我们观察到的化学反应的概念模型。我们将采用这些模型并将其作为地图来帮助我们探索微环境的微生物学：我们将使用遗传数据进行微生物普查；我们将培养、分离和研究那些喜欢微生态环境的细菌；我们的目标是利用从矿山废物样本中分离出来的物质，在实验室的人工系统中重建微环境。最后，我们将利用我们的发现并开发一个更详细的概念模型。该模型将结合我们对矿山废物中存在的细菌的新理解，它们在创造微环境中的作用，它们如何影响微环境中的元素转化，以及对矿山废物整体稳定性的影响。该研究计划的最终目标是通过帮助加拿大矿业公司了解和利用其废物中存在的数十亿微生物的力量来改善可持续采矿实践，并帮助保持我们未来的环境清洁和安全。作为这个研究项目的一部分，我将培养学生在微生物学、地球化学和基于同步加速器的光谱学方面的前沿技能。学生在学习期间将有机会发展产业和学术合作。我将为HQP在矿业和能源领域的就业做好准备，为他们提供沟通和项目管理方面的技能培训，并在项目期间定期为他们提供与潜在雇主建立联系的机会。该研究项目还为学生提供了一个独特的机会，使他们能够在加拿大光源进行培训，从而受益于该设施高度多学科和动态的环境。作为工业界，学术界和监管机构的未来领导者，在该计划中培训的学生将定位于了解将微生物和同步加速器工具纳入解决加拿大一些最具挑战性的环境问题的战略的力量。

Mining is a big part of Canada’s economy, but it also brings us major environmental challenges, including water and soil contamination, disruption of biological systems, and accumulation of voluminous and often toxic mine tailings. Bacteria can cause major problems and major benefits in mine waste management: they can lead to release of toxic elements such as arsenic from rocks, and conversely they can control and prevent release of toxic elements into the environment. It is very important to understand what bacteria are present in a given mine waste, and how they will influence the chemistry of toxic elements in that waste over time. To complicate matters, some bacteria can create microenvironments: tiny niches where the bacteria generate chemical conditions that are very different from the rest of the waste. These microenvironments can have an important influence on the overall chemical stability of toxic elements. Sometimes the bacteria in these niches are relatively rare in numbers, making them difficult to see even with specialized genetic tools - but they can still have a big impact on the waste chemistry. Thus, it is important to study microbially-generated microenvironments, since they could have major implications for how mining companies responsibly manage their wastes. To address this research challenge, I have planned a collaborative and interdisciplinary research program for my students. Our study system will be microenvironments in uranium mine tailings and waste rock from northern Saskatchewan. We will use synchrotron imaging methods to map out the elements and minerals in our samples, and create conceptual models of how microbes may be controlling the chemistry we observe. We will take these models and use them as a map to help us explore the microbiology of the microenvironments: we will use genetic data to take a microbial census; we will culture, isolate, and study the bacteria that prefer the conditions present in the microniches; and we will aim to re-create the microenvironments in artificial systems in the lab using the isolates from the mine waste samples. Finally we will take our findings and develop a more detailed conceptual model. The model will incorporate our new understanding of what bacteria are present in the mine wastes, what their role is in creating microenvironments, how they impact elemental transformations in the microenvironments, and what the implications are for the overall stability of the mine wastes. The ultimate goal of the research program is to improve sustainable mining practices by helping Canadian mining companies understand and harness the power of the billions of microbes present in their wastes, and to help keep our environment clean and safe for the future. As part of this program of research, I will train students in cutting-edge skills in microbiology, geochemistry, and synchrotron-based spectroscopy. Students will have opportunities to develop industry and academic collaborations during their studies. I will prepare HQP for employment in the mining and energy sector by providing them with skills training in communications and project management, and they will also be given regular opportunities to network with potential employers during the program. This research program also offers a unique opportunity for students to base their training at the Canadian Light Source, and thus benefit from the highly multidisciplinary and dynamic environment present at this facility. As future leaders in industry, academia and regulatory bodies, students trained in this program will be positioned to understand the power of incorporating microbiological and synchrotron tools into strategies for addressing some of Canada’s most challenging environmental problems.