Joseph J. Delfino

Quantitative Fourier Transform Infrared spectroscopic investigation humic substance functional group composition

Abstract Infrared (ER) spectroscopy has been widely used for the structural investigation of humic substances. Although Fourier Transform Infrared (FTIR) instrumentation has been available for sometime, relatively little work with these instruments has been reported for humic substances. IR spectroscopy, like other optical spectroscopies, is a quantitative technique that follows the Beer-Lambert Law. An internal standard FTIR technique is described that allows the quantitative comparison of specific IR absorption bands among different humic substances. The technique provides compositional information on the functional groups present in humic substances. The FTIR technique produces information similar to 13C nuclear magnetic resonance (NMR) spectroscopy. However, the FTIR method requires less sample quantity and spectral acquisition times are significantly smaller than required for 13C NMR. This new technique extends the previous qualitative IR spectroscopic studies of humic substances to a quantitative method for the investigation of humic substance structure and composition.

Influence of chemical amendments on phosphorus immobilization in soils from a constructed wetland

Soils previously used for agriculture are currently being converted to wetlands with the goal that they will function as sinks for nutrients. However, residual fertilizer nutrients, especially phosphorus (P) are rapidly released upon flooding. The objective of this study was to evaluate the efficacy of selected chemical amendments in immobilizing the soluble soil P. Soil used in the study was an organic soil, obtained from a 3-month old constructed wetland created on an agricultural land in Lake Apopka Basin, central Florida. Chemical amendments used were: CaCO3, (calcite), Ca(OH)2, CaMg(CO3)2 (dolomite), Al2(SO4) (alum), FeCl3 and mixtures of selected amendments. The effective amounts required for each chemical amendment to minimize P release from soil to overlying floodwater were 7‐15 gk g 1 for CaCO3 and Ca(OH)2 ,1 2 gk g 1 for alum, and 1‐2 g kg 1 for FeCl3. Based on P flux, the order of effectiveness in immobilizing soluble P was as follows: FeCl3\ alum\ Ca(OH)2\ calcite\ dolomite. High rates of chemical amendments are needed to reduce P levels, because of complexation of P binding cations (Ca, Fe and Al) with organic matter.

Influence of redox potential on phosphorus solubility in chemically amended wetland organic soils

Abstract Conversion of agricultural lands to wetlands results in solubilization of residual fertilizer P, thus increasing soluble P concentration of floodwater. Previous studies have shown that application of chemical amendments such as alum, FeCl 3 and CaCO 3 were found to be effective in decreasing soluble P of the soil porewater. Water-table fluctuations and variable hydraulic loading rates in wetlands can alter soil redox conditions, and the solubility of P compounds. The objective of this study was to determine the influence of oxidized and reduced soil conditions on P solubility of a wetland organic soil amended with chemicals. Soil treatments evaluated include: (i) control, (ii) CaCO 3 at 15.3 g kg −1 , (iii) alum at 14.5 g kg −1 , and (iv) FeCl 3 at 1.8 g kg −1 . Dissolved reactive P of soils in the control and FeCl 3 amended soils responded to changes in Eh, while a less pronounced effect was noted in alum and CaCO 3 amended soils. Overall, dissolved P concentrations were higher under reduced conditions and decreased with increase in Eh. The KCl-P (labile inorganic P) decreased with increase in Eh, while NaOH-RP (Fe- and Al-bound P) increased with Eh, especially in control, FeCl 3 and alum amended soils. Soil amended with CaCO 3 showed minimal changes in either KCl-RP or NaOH-RP. In CaCO 3 amended soil, the solubility of P was regulated by the solid phases of Ca-P compounds, while in other treatments solubility was controlled by variscite, strengite, and vivianite. Amendments (such as CaCO 3 and alum) that are less sensitive to changes in redox conditions may be suitable for binding P under wetland environments.

Dissolution rates of three high explosive compounds: TNT, RDX, and HMX.

Incidental exposure to high explosive compounds can cause subtle health effects to which a population could be more susceptible than injury by detonation. Proper source characterization is a key requirement in the conduct of risk assessments. For nonvolatile solid explosives, dissolution is one of the primary mechanisms that controls fate and transport, resulting in exposure to these compounds remote from their source. To date, information describing dissolution rates of high explosives has been sparse. The objective of this study was to determine the dissolution rates of three high explosive compounds, 2,4,6-trinitrotoluene (TNT), hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), in dilute aqueous solutions as a function of temperature, surface area, and energy input. To determine each variables impact on dissolution rate, experiments were performed where one variable was changed while the other two were held constant. TNT demonstrated the fastest dissolution rate followed by HMX and then RDX. Dissolution rate correlation equations were developed for each explosive compound incorporating the three aforementioned variables, independently, and collectively in one correlation equation.

Comparison of sediment extract microtox® toxicity with semi-volatile organic priority pollutant concentrations

A total of 105 sediment samples were extracted with acetonitrile and subjected to cleanup with C-18 columns and copper powder. Extracts were analyzed for semi-volatile organic priority pollutants and for acute toxicity using the Microtox® bioassay. Polynuclear aromatic hydrocarbons (PAHs) accounted for 85% of all priority pollutant identifications. The results of statistical comparisons made between PAH concentrations and extract toxicity depended upon the correlation procedures used. Total PAHs were significantly correlated with toxicity using Spearmans correlation procedure, but not correlated using a linear correlation procedure. Many extracts with below or barely detectable levels of priority pollutants were highly toxic. On an individual extract basis, concentrations of priority pollutants were poor indicators of extract toxicity. Toxicity determinations were also made for commonly detected priority pollutants dissolved in dimethyl sulfoxide.

Heavy metals in the environment : using wetlands for their removal

Introduction and Background Introduction, Gaia Wetland and Heavy Metals Problems and Needs Review of Published Studies, Lead and Wetlands Biogeochemical Cycle of Lead and the Energy Hierarchy Lead in a Cypress-Gum Swamp, Jackson County, Florida Ecological Assessment of the Steele City Swamp Lead Distribution in Steele City Swamps Experiments with Lead and Acid in Wetland Microcosms Simulation Model of a Lead-Containing Swamp Ecosystem Lead and Wetlands in Poland Lead and Zinc Retention in the Biala River Wetland in Poland Perspectives on Heavy Metals Manufacturing, and Environment in Poland Value and Policy Ecological Economics of Natural Wetland Retention of Lead Emergy Evaluation of Biala River Wetland and Its Lead Retention The Evolution of Environmental Law and the Industrial Lead Cycle Summary Policy for Heavy Metals and Environment Appendices References

Nonaqueous Phase Liquid Dissolution and Soil Organic Matter Sorption in Porous Media: Review of System Similarities

We examine similarities in constraints to mass transfer of hydrophobic organic compounds (HOCs) between the aqueous and various organic phases in porous media at the grain scale. Published research and data are reviewed regarding equilibrium coefficients and first-order rate constants for mass transfer of HOCs between water and natural organic matter present in various geosorbents (e.g., soils, sediments, and aquifer solids), and several oils (petroleum products, decane, and coal tar). We propose how these equilibrium and mass-transfer coefficients can be estimated by methods common to all organic phases. Equilibrium coefficients can be reliably estimated using Raoults law. First-order rate constants obtained from extensive literature data appear to be dependent on aqueous-phase diffusion and duration of exposure (or contact). The aqueous diffusion domain may be either an interfacial film (for low viscosity oil ganglia) or a retarded immobile water zone (for geosorbents).

Partitioning of organic and inorganic components from motor oil into water

Abstract Partitioning of several volatile organic compounds (VOCs), polynuclear aromatic hydrocarbons (PAHs), and metals from new and used motor oil into water was investigated. Equilibrium distribution of these compounds between water and motor oil was measured using EPA Methods 624, 625, and 200 series. The intent was to establish chemical indicators to assist in identification of groundwater contamination from motor oil disposal/spill sources. Also, data from VOCs and PAHs was used to evaluate Raoults law (ideal mixtures) behavior for oil-water distribution.

Polychlorinated biphenyls in the fish and sediment of the Lower Fox River, Wisconsin

ConclusionsPollution abatement technologies instituted by recycling paper mills have resulted in a decrease in PCBs in final effluents discharged to the Lower Fox River. Concurrent declines in fish PCB body burdens have also been noted. It is not certain, however, whether the resultant decrease in PCB final effluent concentrations is sufficient to protect aquatic life from bioaccumulation of PCBs above an acceptable level. Furthermore, sediment PCB concentrations remain high in previously impacted areas.

Non-regulated organic compounds in Florida sediments

Abstract Sediment sample extracts initially analyzed by gas chromatography/mass spectrometry during a state-wide study of organic priority pollutants, were re-evaluated using a broad spectrum approach. Mass spectra for most of the non-regulated organic compounds present in each sediment sample extract were screened. Mass spectral data for these non-regulated organic compounds were organized into a spreadsheet database. The non-regulated organic compounds in the database were prioritized and fifteeen of the most frequently occurring compounds or compound groups were chosen for further study and potential identification. Four compounds, calamenene, dehydroabietine, retene and benzo(b)naphtho(2,1-d)thiophene were positively identified. Tetrahydroretene was tentatively identified while three compounds remain unidentified. Seven compound groups, including alkylbenzenes, alkylphenols and polycyclic aromatic hydrocarbons (PAHs) contained many isomers so complete identification of the individual isomers within each group was not attempted. Information on possible sources and environmental or toxicological impact of these chemicals was obtained from the literature.