Date of Award
Geology and Geological Engineering
Arsenic is pervasive throughout North Mississippi’s soils (Pettry and Switzer, 2001; Fordham and Norrish, 1983 and; Kaiser and Guggenberger, 2003). This is largely due to the use of pesticides and herbicides in past and present years, as arsenic is a fundamental component in chemicals used for agricultural purposes. Soils contaminated with arsenic present a serious hazard to human health due to the possibility of contaminating surface and groundwater, as well as food through plant uptake of arsenic. Consequently, it is important to understand the process and effects of arsenic absorption in soil. The focus of this research is on the soil structures at the UMFS, with emphasis on its blocky and granular peds, and their correlation to arsenic concentration. 70 soil samples from the UMFS were collected and their spatial location identified. Each sample was split. One split was sent to ETC Inc. in Memphis, TN, for arsenic testing, and the other sample split was dried and loosely crushed, in order to preserve peds, for sieve analysis. Sieve analysis was carried out to separate blocky peds, granular peds and loose fine grained soils. Three soil categories were defined by the sieve analysis: fine-grained materials (<0.063mm), granular peds (0.063- 0.6 mm), and large peds (1.18mm to >4.75mm). The fine grained materials mainly represent the unstructured soil materials between ped aggregates. The granular peds are small aggregates similar to the microaggregates reported by Jiang et al. (2005), and the large peds are slightly disturbed blocky peds. The statistical relationship between arsenic concentration and each of the soil categories was evaluated. Variograms were constructed to determine the spatial structure of the arsenic and each of the soil categories. The spatial structure of the arsenic concentrations were illustrated using kriged and cokriged maps.
Okoye, Elsie Ekene, "Geostatistical Analysis of Arsenic in Soils at the University of Mississippi Field Station." (2013). Honors Theses. 2082.