The regional influence of an oil-fired power plant on the concentration of elements in native materials in and near south Florida national parks

Abstract

ILLUSTRATIONS 4. The facility burns a mixture of fuel oil and natural gas. The oil contains about 1 percent total sulfur and the natural gas about 9.6 kg of sulfur per 10" m^. The oil/gas consumption ratio, however, is variable over time and therefore the amount of sulfur emitted is also highly variable. Our study should be viewed as an integrated "snapshot" of the influence of the power plant over about a one-year period (the plant material sampled was from the previous growing season) and any extrapolation of these data should be done with appropriate caution. 5. All plant, soil, and oil samples were analyzed for the total concentration of twenty-four elements. Also, all plant and oil samples, and selected soil and seawater samples, were analyzed for stable sulfur isotope abundances. 6. Sodium and total sulfur levels in plant leaves decrease with increasing distance from the coast along all three traverses. These trends are strong evidence that the sea is a source of these elements in vegetation. Total sulfur levels along the power plant traverse are only slightly elevated when compared to samples along the other two traverses. 7. The relative abundance of stable sulfur isotopes in vegetation helps discriminate the sulfur in vegetation that is being contributed by the sea from that which is being contributed by the operations of the power plant. Fuel oil samples possessed 634 sulfur values equal to about zero °/ e « and the only similar s^sulfur values in vegetation were found at a site 0.97 km from the power plant. Marine sulfate has a ^sulfur of about +20°/«« and samples collected elsewhere near the coast appear to reflect the influence of the addition of sulfate with this large positive value. 8. Vegetation and soil samples collected along a north-south traverse (traverse 4) progressing away from a portland cement manufacturing facility showed no meaningful element concentration versus distance trends. 9. Except for collections along traverse 4 (cement plant/agriculture traverse), the soils encountered in this study were highly variable in their composition and their utility as a sampling medium for the definition of measurable power plant emission effects is limited. 10. No significant difference was found between the element concentration of plant leaf samples collected while wearing rubber gloves to identical samples collected while not wearing gloves. 11. Samples of young and old Casuarina equisetifolia wood from trunks of 10-year-old trees showed no historical difference in element concentrations between the sections. Trends of decreasing molybdenum concentration in young and old wood with increasing distance from the coast and power plant could not be explained as being the result of operations at the electrical generation facility.

The Use of Stable Sulfur Isotope Ratios in Air Pollution Studies: An Ecosystem Approach in South Florida

“…(l975a) found essentially no isotopic fractionation between the oil feedstock and the flue gases. However, they detected a decrease (about 4%0 " Gough et al (1986).…”

“…Actual measurements of sulfur isotope ratios for plants in this ecosystem show quite surprising results with a broad range of f, 34 S values, several of which were heavier than the f, 34 S value for seawater (Gough et al 1986). A f, 34 S frequency distribution for 92 samples of five different species collected in the south Florida coastal area near the Turkey Point power plant is shown in Figure 27.5.…”

“…The sulfur cycle model is based on a regional study that was designed to determine the influence of emissions from the oil-fired Turkey Point power plant on vegetation in and near Everglades and Biscayne national parks (Gough et al 1986). Objectives of the study were to distinguish between anthropogenic and natural sulfur and trace-metal sources and estimate the region of measurable influence of the power plant emissions.…”

“…Due to the recent age of the limestone, one might expect positive 3 34 S values close to that of modern-day seawater sulfate. Total sulfur for one sample of limestone collected in the everglades had a 3 34 S value of + 13.6%0 (Gough et al 1986). This value is very similar to isotopic ratios measured in several mineral soils from the rocky glades and coastal ridge area of the everglades ( + 11.9, + 12.8, + 12.6, and + 10.0%0).…”

“…In order to assess the impact of the Turkey Point power plant on vegetation in and near Everglades and Biscayne national parks, element content and sulfur isotope ratios were examined in vegetation and soils with respect to distance from the plant along three parallel east-west traverses (Figure 27.1) (Gough et at. 1986).…”