The mining industry generates a significant amount of mine tailings, pulverized rock that remains after the valuable metal-bearing minerals have been extracted. The generated mine tailings are collected and transported in the form of a slurry or paste to large on-site impoundments. The tailings impoundments range in size from a few hundred to a few thousand acres. Water in the tailing slurry is recovered for reuse and the solid material is left for long-term storage. In arid and semiarid areas such as the regions of the southwestern United States, mine tailings can become wind borne and result in particulate emissions. The environmental impacts of this dust include reducing visibility, degrading air quality, and contaminating surface water and soils. Although different methods have been attempted for mine tailing dust control, they all have limitations. There is an urgent need for developing ecofriendly and cost-effective methods for mine tailing dust control. The overarching goal of this research is to investigate the effects of factors on the establishment of biocrusts (specialized organisms covering the surface) on mine tailings and evaluate the physical, chemical, mechanical, and environmental behavior of biocrust-stabilized mine tailings at multiple scales. Successful completion of this project will benefit society through the development of new fundamental knowledge that could lead to an ecofriendly and cost-effective dust control technology for addressing the adverse effects of mine tailing dust. Further benefits to society will be achieved through outreach and educational activities including the mentoring and training of one graduate student for the duration of the project and two undergraduate students per year at the University of Arizona. Mine tailings in arid and semiarid areas are prone to wind erosion and the associated contaminants can be dispersed throughout the environment as dust particles, causing serious deleterious effects on the environment and human health. The overall goal of this research is to develop an ecofriendly and cost-effective method for sustainable mine tailing dust control. To achieve this goal, the proposed research takes a multi-scale and multi-disciplinary approach and will 1) conduct systematic laboratory studies to define and optimize the parameters for culturing cyanobacteria and growing biocrusts on mine tailings, 2) characterize the biocrust-stabilized mine tailings to relate the macro-scale behavior to the micro/nano-scale characteristics and understand the underlying mechanism of stabilization and dust control based on biocrust establishment, and 3) demonstrate and validate the integrated biopolymer stabilization and biocrust establishment technology dust control and other environmental benefits by conducting field tests. The proposed technology for ecofriendly mine tailing dust control is based on integrated biopolymer stabilization and biocrust establishment and may lead to a new paradigm for dust control and environmental protection. The study systematically investigates the effect of different factors on the establishment of biocrusts on mine tailings and evaluates the physical, chemical, mechanical, and environmental behavior of biocrust-stabilized mine tailings at multiple scales. Successful completion of this project will elucidate the fundamental science on biocrust-mine tailing interactions and lead to better understanding of the underlying mechanism of stabilization and dust control based on integrated biopolymer stabilization and biocrust establishment. Additional education and outreach activities include a summer camp for K-12 students through the Summer Engineering Academy at the University of Arizona, development, and display of an exhibit at Biosphere 2, and mentoring of undergraduate and graduate students. 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.