Masters Theses

Abstract

"The trends of concentration of lead vs. depth found soil samples collected in 1998 from near Doe Run Co.'s Buick Lead recycling smelter are not significantly changed from those seen in previous studies in 1975 and 1988. The maximum concentration of lead observed in samples from four soil cores examined in this study was 34,000 parts per million, and was in the decomposed leaf litter at the surface. The lead concentration decreases exponentially with depth in the top two to three inches of soil, and a decreasing trend with distance from the smelter is illustrated by three of the four cores. These samples also show the concentrations of cadmium, copper, cobalt and phosphorous to be significantly enriched in the upper, organic (Oh) soil horizon compared to samples from deeper soil horizons. There are, however, some notable changes in the present-day metal concentrations compared to those often and twenty-three years earlier. Arsenic, zinc and nickel display an initial decrease in concentration from surface to one to three inches depth, but concentrations then rise slightly after five to six inches depth. These increases at depth can be correlated with both a steady increase in iron concentration and the proportion of smectite clay with depth. The previous studies also displayed the highest contaminant concentrations in the Oh layer, but the slight increases of arsenic, zinc, and nickel at depth have not previously been reported. Scanning Electron Microscopy / Electron Dispersive Spectroscopy (SEM / EDS) analysis of the soils indicate lead was primarily associated with Fe and Mn oxides. In one sample, however, lead was present in a phase with cubic morphology and a composition intermediate between PbS and PbSO4. The morphology and composition of this particle suggests the presence of a residual core of galena (PbS) that has been partially altered and is now covered with a rim of anglesite (PbSO4). Arsenic and zinc were often found at minor concentrations associated with the lead, while cadmium and other metals were not present at high enough concentrations to be detected with SEM / EDS. The soil pH was found to decrease with depth. This trend does not match the data of previous studies in the area, or that of a normal temperate soil profile. Deposition of stack emissions of a slightly basic nature (pH =7.4) may explain the abnormal pH trend observed in the soil"--Abstract, page iv.

Advisor(s)

Wronkiewicz, David J.

Committee Member(s)

Laudon, Robert C.
Gale, Nord L.

Department(s)

Geosciences and Geological and Petroleum Engineering

Degree Name

M.S. in Geology and Geophysics

Sponsor(s)

Radcliffe Trust Fund

Publisher

University of Missouri--Rolla

Publication Date

Fall 2000

Pagination

x, 89 pages

Note about bibliography

Includes bibliographical references (pages 87-88).

Geographic Coverage

Iron County (Mo.)

Rights

© 2000 Brad Alan Rucker, All rights reserved.

Document Type

Thesis - Restricted Access

File Type

text

Language

English

Library of Congress Subject Headings

Soils -- Trace element content -- Measurement.
Soils -- Trace element content -- Missouri -- Iron County
Metals -- Environmental aspects

Thesis Number

T 7860

Print OCLC #

45814237

Electronic OCLC #

906036274

Link to Catalog Record

Electronic access to the full-text of this document is restricted to Missouri S&T users. Otherwise, request this publication directly from Missouri S&T Library or contact your local library.

http://laurel.lso.missouri.edu/record=b4505643~S5

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