Date of Award

6-2003

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Environmental Science

First Advisor

Dr. A.M.O. Mohamed

Second Advisor

Abdulrazaq Zekry

Third Advisor

Dr. Loretta Li

Abstract

The United Arab Emirates produces a large quantity of elemental sulfur from oil and gas industry. Elemental sulfur is widely used as soil treatment technique for reducing pH of alkaline soils than other techniques because it is cheaper and safer during treatment.

In this study, different designs mixes were prepared based on its content of sulfur and calcium carbonate. Different application rates of elemental sulfur (0, 1, 2, and 3%S) were added to soils having different amounts of calcium carbonates (i.e., 16.2, 21.2, 26.2, 36.2, 46.2, and 56.2% for basic mix design, and mix designs types I, II, III, IV, and V, respectively. The changes in soil pH, electrical conductivity (EC) and sulfate concentration were measured at different time intervals (0, 5, 10, 20, 40 and 80 days) and statistically analyzed. Furthermore, mineral transformations were quantified via scanning electron microscope, x-ray diffraction analysis and energy depressive x-ray techniques. Mineral transformations were further analyzed in view of possible chemical reactions and thermodynamic modeling.

The study concluded that sulfur addition for all treatments of basic mix design, mix design types I, III, IV, and V has no significant influence on pH changes but has high significance on pH changes for mix design type II as determined via statistical analysis. In this mix design, pH decreased by 1.14, 1.22, 1.27, 1.24 and 1.28 units after 5, 10, 20, 40, 80 days, respectively. For all treatment cases, sulfur addition has high influence on EC changes except for mix design type III that indicates no significance. For sulfur oxidation, similar conclusion to EC changes was reached. Furthermore, available water-soluble sulfate was highly correlated with EC. As sulfate increases, EC increases and vice versa.

Share

COinS