Spatial Distribution of Petroleum Hydrocarbons in Sediment Cores from Blind Pass, St. Pete Beach, Florida

One hundred and one sediment cores were collected to characterize the spatial distribution of petroleum hydrocarbons within and just outside Blind Pass, St. Pete Beach, Florida. Twenty-five percent of the cores exhibited levels of petroleum hydrocarbons above detection limits of the gas chromatograph/flame ionization detector (GC/FID) (0.01 mg/Kg), but at generally low concentrations. Petroleum hydrocarbon speciation studies of these samples (gas chromatography/mass spectroscopy [GC/MS]) indicate above-detection level (1 μg/Kg) petroleum hydrocarbons are similar to the non-volatile petroleum hydrocarbons found in a Bouchard 155 reference sample collected after the 1993 oil spill in the area, but are in a much degraded and weathered state. Individual petroleum hydrocarbons were, in all but one case, below the threshold effective level (TEL) described in the literature (MacDonald, 1994). The petroleum hydrocarbons were primarily found at 100-300 cm depth in Blind Pass cores. Above-detection level petroleum hydrocarbons were generally found in samples from cores in the center of the channel, near the edges of the shoal, and just outside of Blind Pass. A second mixture of hydrocarbons, primarily phthalates, ketones, and ether, was found at relatively shallow core depths (0-99 cm) in the Mid- and North End Channel cores. These suggest a separate source of contamination, possibly storm water runoff. The fuel fluorescence detector (FFD) probe was investigated for its ability to detect petroleum hydrocarbons in marine sediments. When analyzed with the FFD, all sediments from the cores produced peaks of fluorescence, but none above the background levels of Blind Pass native sediments. All but two samples analyzed by GC/FID were below the detection limits (100 ppm) of the FFD. These samples were found in dark-colored sediments. The combination of the detection limits of the instrument, sediment color, and the degraded nature of the heavier weight petroleum hydrocarbons may have resulted in fluorescence outputs below background levels. These studies demonstrate that the distribution of petroleum hydrocarbons within Blind Pass sediments is generally low and patchy. However, 25% of the cores exhibited levels above detection using GC/FID/MS. These cores could be subjected to individual speciation studies which indicate generally below TEL levels and an association of some, but not all, with the 1993 oil spill in Blind Pass. Appendix A provides photographs and tables for sediment subsamples which exhibited total petroleum hydrocarbon concentrations above detection limits, while Appendix B presents the results from fuel fluorescence detector probe analyses. A discussion of the results of the study in relation to sediment quality guidelines and soil cleanup target level guidance documents is included as Appendix C. Some preliminary results using the above techniques on core samples from the nearby John’s Pass are presented in Appendix D

Boynton-Delray Coastal Water Quality Monitoring Program

This report discusses a sequence of six cruises in the vicinity of the Boynton-Delray (South Central) treated-wastewater plant outfall plume (26°27\u2743 N, 80°2\u2732 W), the Boynton Inlet (26°32\u2743 N, 80°2\u2730 W), and the Lake Worth Lagoon, Palm Beach County, Florida. The sampling cruises took place on June 5-6, 2007; August 28-29, 2007; October 18-19, 2007; February 14 and 18, 2008; May 19-20, 2008; and July 11-13, 2008. Water was sampled at 18 locations at the surface, middle, and near the seafloor (where there was sufficient depth) for a total of 45 samples; these samples were analyzed for a variety of nutrients and related parameters. The water sampling unit contained a conductivity-temperature-depth (CTD) instrument from which data were obtained at each sampling site. Synchronal ocean current data were measured by a nearby acoustic Doppler current profiler (ADCP) instrument. The inlet measurements were consistently lower in salinity and more acidic (lower in pH) than the coastal ocean and were warmer during the May and, especially, during the February cruises. For most analytes, viz., nitrite+nitrate (N+N), total suspended solids (TSS), chlorophyll-a, silica (Si), and total dissolved nitrogen (TDN), the lagoon concentrations were significantly higher than the coastal ocean; the inlet concentrations appeared to be consistent with lagoon water with partial mixing with the coastal ocean, as expected. Estimates of the nutrient flux to the coastal ocean were computed: approximately 1,500 kg of dissolved nitrogen (N), 2,350 kg of silicate (Si), 33 kg of orthophosphate (P), and 59 kg of ammonium (NH4) per day were delivered to the coastal ocean through the inlet. The outfall boil at South Central outfall (the smallest in volume of the six outfalls in southeast Florida) is only visible under ideal conditions. In the six cruises described in this document, the outfall boil could be found in only one cruise (August 28-29, 2007). Elevated concentrations of nutrients (N+N, P, Si, and P) at the outfall vicinity were measured, and these concentrations decreased rapidly away from the outfall for most analytes, to become undistinguished from the background within 3 km or less. Not finding the boil, however, in five of six cruises meant that the waters with the highest concentrations were probably missed. When the boil was sampled in August 2007, N+N, P, and total dissolved phosphorus (TDP) concentrations at the boil were roughly the same as from the inlet. For other analytes (chlorophyll-a, TSS, Si, and dissolved organic carbon [DOC]), the concentrations at or near the outfall were significantly less than those from the lagoon and inlet on most of the cruises. The coastal ocean appeared to be significantly impacted by the Boynton Inlet and less so from the inlet. A suggestion of a source to the south was seen in some analytes. Measurements from the Gulf Stream Reef area were the lowest in the study, and may provide “background” concentrations for this region. As expected, the coastal ocean was warmer and more stratified in the summer compared to the winter, e.g., whereas no thermocline was noted in the CTD data from February 2007, a strong thermocline was observed in most casts during July 2008. In certain cases (e.g., N+N in June 2007, pH in July 2008), an increase in the concentration (decrease for pH) from north to south implied a source from the south, e.g., the Boca Raton Inlet or Boca Raton outfall

Chiral tetranuclear and dinuclear copper(II) complexes for TEMPO-mediated aerobic oxidation of alcohols : are four metal centres better than two?

The one-pot reaction of 3,5-di-tert-butyl-2-hydroxybenzaldehyde, (R)-2-aminoglycinol and Cu(OAc)2·2H2O in a 1 : 1 : 1 ratio in the presence of triethylamine led to the isolation of X-ray quality crystals of the chiral complex (R)-1 in high yield. The single crystal structure of (R)-1 reveals a tetranuclear copper(II) complex that contains a {Cu4(μ-O)2(μ3-O)2N4O4} core. A reaction using (1S,2R)-2-amino-1,2-diphenylethanol as precursor under the same conditions generated the chiral complex (S,R)-2; its structure was determined by single crystal X-ray crystallography and was found to contain a {Cu2(μ-O)2N2O2} core. Both (R)-1 and (S,R)-2 have been used for catalytic aerobic oxidation of benzylic alcohols in combination with the TEMPO (2,2,6,6-tetramethylpiperidinyl-1-oxyl) radical. (R)-1 selectively catalyses the conversion of various aromatic primary alcohols to the corresponding aldehydes with high yields (99%) and TONs (770) in the air, while (S,R)-2 exhibits less promising catalytic performance under the same reaction conditions. The role of the cluster structures in (R)-1 and (S,R)-2 in controlling the reactivity towards aerobic oxidation reactions is discussed

Sugli spazi

L'articolo, in forma dialogica, illustra l'analisi e lettura degli spazi urbani attraverso gli strumenti della semiotica. Vengono proposti esempi di applicazione dei concetti di sintassi, semantica e pragmatica alla struttura urbanistica. Vengono discusse le differenze tra spazi aperti e multiuso e spazi rigidi e polifunzionali