Date of Degree MS (Master of Science) Civil and Environmental
Engineering Michelle M. Scherer Iron is ubiquitous in the
environment mostly as stable iron hydr(oxides) such as hematite
(α-Fe2O3) and goethite (α-FeOOH). The Fe(II)-Fe(III) redox
couple plays a vital role in nutrient cycling, bacteria
respiration, and contaminant removal. This redox couple,
however, can be affected by external influences such as anion
adsorption of sulfate, oxalate, and phosphate which can
influence various goethite properties including the point of
zero charge. This study attempts to determine the effect of
phosphate sorption to a goethite surface and its subsequent
influence on Fe(II) sorption. The objectives, specifically, were
to quantify phosphate sorption on a goethite surface using
colorimetric methods and to use Mössbauer spectrometry to
determine if electron transfer occurred after a layer of
phosphate was adsorbed to the goethite surface. The hypothesis
of this study is as follows: an adsorbed layer of phosphate on a
go