Recovery of rare earth elements (REEs) from coal fly ash (CFA) is a promising resource recovery and waste recycling option that might bring about significant economic and environmental benefits. However, many challenges need to be addressed in order to develop cost effective and environmentally friendly techniques for REE recovery from CFA. The overall goal of this dissertation is to develop a synergistic approach to simultaneously achieve REE recovery from CFA and waste reduction.

The tropical Pacific is a dominant influence on global climate, from interannual to glacial-interglacial timescales. How this system will respond to anthropogenic greenhouse gas forcing, however, remains an area of large uncertainty. In order to better our understanding of how the tropical Pacific ocean-atmosphere system has responded to greenhouse gas forcing in the past, I have generated new reconstructions of sea surface temperature (SST) in the central equatorial Pacific over the last ~150,000 years.