Advances in Reactive Transport Modeling of Geochemical Systems: Applications to Acid Rock Drainage and the Evolution of the Critical Zone.

摘要

Advances in computational science have increased its use in understanding and mitigating multi-faceted environmental problems at a time when the preciousness of our natural resources has been realized. The prospect of using multi-dimensional models to aid in the understanding of complex environmental systems spurred my desire to contribute to this field as both an environmental engineer and computational scientist. During my graduate study, I researched, developed, and improved computational models of acid rock drainage (ARD). I also worked on a model of a natural hillslope in the Boulder creek Critical Zone Observatory (BcCZO), which was used to investigate the geochemical evolution of the critical zone (CZ). Both phenomena are commonly observed in the field, but the development of reactive transport models will further our understanding of what drives these systems. Furthermore, reactive transport models can be used to predict system response to dynamic environmental variables such as those pertaining to climate change.;Chapter one delves into modeling efforts accomplished for this dissertation that are related to primary mineral weathering and the formation of the subsurface CZ. In Chapter two, ARD reactive transport modeling efforts are described that pertain to both laboratory experiments and natural sulfide deposits. Both problems benefit from improved multi-scale models of the coupled interactions between hydrology, geochemistry, and microbiology. Applying advances in computational science to these types of problems is leading to an unprecedented understanding of the interactions of rock, water, and life. Subsurface flow and transport models are vital tools to help inform decisions for the advancement of environmental stewardship. Improving the capabilities of these multi-scale models will allow first-principles formulation of physical, chemical, and microbial processes, facilitating informed use and management of the environment.