Research Overview

We study biogeochemical processes that affect the fate of trace metals in natural and engineered systems. A central theme to our work is the utilization of chemical speciation for understanding and predicting the persistence, mobility and bioavailability of metals and minerals in the aquatic environment. Our group is currently involved in the following projects:

Bioavailability and Methylation Potential of Mercury in Aquatic and Soil Ecosystems

In our group, we investigate the relationship between geochemical forms of Hg in contaminated ecosytems and microbial methylation potential, a poorly understood relationship that hinders progress towards effective site management.

Environmental Health Consequences of Mercury Exposure for South American Communities

Artisanal and small-scale gold mining represents the largest anthropogenic source of Hg emissions to the atmosphere. We study how such practices result in regional pollution of mercury and health impacts for communities exposed to this chemical toxin.

Coal Ash Wastes: Environmental Impacts of Disposal

Objectives of coal ash research in the Hsu-Kim group are two-fold: 1) To delineate the chemical forms of potentially toxic trace elements such as arsenic and selenium in various types of coal ash residuals; and 2) To understand how the chemical form of these elements as well as ash storage conditions influence the mobility and transformations of these elements.

Waste-to-Resource: Rare Earth Element Separations From Geological Residuals

We study methods to extract and purify rare earth elements from geological waste residuals such as coal ash and mine wastes. Our efforts aim to describe the chemical and physical characteristics of waste feedstocks and how such insights inform extraction rates and efficiencies.

Environmental Nanogeoscience

The environmental nanogeosciences involve the study of environmental materials (such as soil, water-solid interfaces, organic and inorganic particles) and nano scale processes that affect chemical reactivity, mobility, and availability to biota. These material can be derived from naturally occuring processes or from anthrophogenic acitivities (e.g. engineered nanomaterials, incidentially produced from human activities).