Welcome

1. Manganese oxides and their applications

Manganese oxides participate in cation exchange and redox reactions. These properties lend them to applications in the uptake of contaminant metals such as lead, zinc, and nickel. Their redox properties also make them important in the oxidation of water during photosynthesis, and consequently, a contender for water oxidation in solar cell technology. I collect natural manganese oxides from acid mine drainage remediation sites and similar environments where manganese oxides form, along with synthesizing manganese oxides in the laboratory. These materials are especially difficult to characterize due to their poor crystallinity, small particle size, and presence of three oxidation states for Mn (2+, 3+, 4+). I have worked on characterizing these samples with unparalleled detail in order develop a suite of techniques to understand the relationship between crystal structure and Mn oxidation state. I then examine the effects of manganese oxide properties on the uptake of metals to evaluate their effectiveness in contaminant uptake.

2. Barite precipitation and contaminant uptake

The fracking of shale reservoirs for natural gas have produced high salinity wastewaters containing contaminants from the subsurface, including hazardous ions such as Ra, Sr, and As. The formation of the mineral barite can uptake some of these ions during precipitation. The effectiveness and stability of contaminants co-precipitated with barite at varying salinities and in the presence of organic chemicals that are also found in fracking wastewater must be evaluated and engineered for optimal uptake.

3. Carbonate precipitation in porous media

Global climate change calls for efforts to mitigate atmospheric CO₂. The sequestration of CO₂ in geologic reservoirs serves as one path for mitigation. However, the stability of subsurface CO₂ remains uncertain, and technology to seal leaks within reservoirs may be necessary. I seek to understand mineralization reactions in porous media with the goal of eventually engineering carbonate precipitation to seal leaks that may occur within the rock in which CO₂ is stored.