Suama Ndengu

Date of Award


Degree Name

Master of Science


Geological and Environmental Sciences



First Advisor

Dr. Carla M. Koretsky

Second Advisor

Dr. Johnson Haas

Third Advisor

Dr. Alan Kehew

Access Setting

Masters Thesis-Open Access


Improved prediction of the transport and bioavailability of metals in contaminated sediments demands a better quantitative understanding of how metals partition between aqueous solutions and mineral phases. This research examines the partitioning of nickel in a contaminated aquifer from Grand Rapids, Ml. Contaminated aquifer sediments were examined using the five step Tessier et al. (1979) operationally defined sequential extraction procedure to determine the solid phase distribution of nickel in the aquifer sediments. Models used to guide remediation efforts at the contaminated site assume that Ni behavior can be predicted based on Ni adsorption onto ferrihydrite (HFO). Although sequential extraction results from this study demonstrate that Ni partitions primarily into Fe/Mn oxide phases, adsorption experiments demonstrate that interactions between nickel and aquifer sediments cannot be predicted from Ni adsorption onto HFO alone. This research shows that other phases present in the aquifer, e.g. clay minerals, Mn oxides or organic matter, may significantly affect Ni speciation. The combination of sequential extraction methods and adsorption experiments used in this study significantly advance the empirical understanding of Ni distribution in the subsurface, thus aiding the selection of appropriate remedial efforts for contaminated sediments.

Included in

Geology Commons