One of the fundamental processes controlling the fate of hydrophobic organic and inorganic pollutants in aquatic environments is their partitioning between the dissolved and sorbed state. Recent research evidence suggests that their speciation should include a three phase system (stationary sorbed, mobile dissolved, and mobile sorbed) otherwise, our environmental exposure and risk assessments may significantly underestimate their actual mobility and transport to groundwater.

Laboratory column and field research experiments at UK have shown that suspended colloidal particles, especially organically enriched, may promote the transport of hydrophobic pollutants, such as pesticides and heavy metals by: (a) preferentially sorbing and carrying contaminants through soil macropores, (b) enhancing contaminant solubility, and (c) facilitating preferential desorption and remobilization of soil matrix-retained pollutants. The presence of mineral colloids in water suspensions enhanced the transport of atrazine through soils by 3-18%, and metolachlor by 22-70%, depending on colloid and soil properties. Similarly, the transport of heavy metals was increased by 2 to 30 times for Cu and Zn and up to 3,000 times for Pb in the presence of colloids. Using colloid suspensions as flushing solutions enhanced desorption and remobilization of Pb up to 12 times over deionized water flushing solutions in contaminated intact soil columns.

The findings of these studies provide a more realistic picture of potential ground and surface water contamination by environmental pollutants and can help improve predictions and remediation strategies of contaminant migration and removal.

Acid mine drainage (AMD) from abandoned mines has significantly impaired water quality in eastern Kentucky. A small surface flow wetland constructed in 1989 to reduce AMD effects and subsequently failed after six months of operation was renovated by incorporating anoxic limestone drains (ALDs) and anaerobic subsurface drains promoting vertical flow through successive alkalinity producing limestone/organic compost beds. Two years of post renovation monitoring indicate that mean iron concentrations have decreased from 787 to 39 mg L^-1, pH increased from 3.38 to 6.46and acidity has been reduced from 2244 to 199 mg L^-1, (CaCO₃ equivalent). Mass removal rates averaged 98% for Al, 95% for Fe, 94% for acidity, 55% for sulfate and 49% for Mn during the study period. The combination of ALDs and SAPS technologies used in the renovation and the sequence in which they were implemented within the wetland system appeared to provide sufficient buffering and longer residence time rendering a promising design for treatment of this and other source of high metal load AMD.

The western Pennyroyal region of Kentucky is underlain by high purity Mississippian limestones with highly expressed karst topography. Studies are being conducted in typical karst basins to assess soil hydrology, deposition patterns, and karst basin stability. Major depositional events in two basins were evaluated from macro- and micromorphological observations, physicochemical properties and ¹⁴C dating. Sedimentation rates and karst basin stability interpretations were based on ¹⁴C dating and activities of ¹³⁷Cs from nuclear fallout.

Morphological observations suggested the presence of buried soils. Thin section micromorphology evaluations confirmed the presence of buried soils (better pedality expression, brighter birefringence) in spite of the uniform silt loam texture throughout the excavated profile depths. Organic carbon content fluctuated irregularly with depth reflecting the age differences as well as the different land use management between time spans. Age discontinuities were evidenced by sharp decreases in the silt/medium sand (Si/MS), silt/fine sand (Si/FS), and CEC/Mg ratios in the Ab horizons. The vermiculite/mica (V/M) ratio was also a useful discontinuity indicator, but quartz content, quartz/feldspar (Q/F) and Ti/Zr ratios were not as consistent.