Identifying Ash-Derived PAH in Soil and Sediment

Stephen Emsbo-Mattingly, M.S., Allen Uhler, Ph.D., Scott Stout, Ph.D., Kevin McCarthy, Battelle Memorial Institute, 397 Washington Street, Duxbury, MA 02332, Tel: 781-934-0571

The identification of PAH origins can include numerous site specific and regional background sources.  Ash constitutes a source of interest, because some States passed laws exempting remediation of ash-derived PAH.  This exemption typically exists for several possible reasons.  First, it removes environmental liability from residential property owners with coal or wood ash disposal areas on their property.  Second, it may reflect the lower mobility of tightly-bound, high molecular weight PAH.  This presentation describes several lines of evidence that help source PAH to ash.  

The primary evidence for ash derived PAH patterns is revealed in the detailed PAH fingerprint.  The PAH fingerprinting method includes measured concentrations of parent, alkylated, and heterocyclic PAH and very low detection limits.  At a minimum, this method outperforms traditional PAH measurement techniques used for regulatory compliance (e.g., EPA 8270) in terms of analyte specificity and sensitivity.  However, secondary evidence is often required.  Several protocols will be discussed for revealing the nature of the carbon material from which the ash was generated.  The carbonaceous feedstock may include coal, petroleum, wood, and municipal wastes.

Identifying and Dating Creosote Releases in the Environment

Stephen Emsbo-Mattingly, Scott Stout, Allen Uhler, and Kevin McCarthy, Battelle Memorial Institute, 397 Washington Street, Duxbury, MA 02332, Tel: 781-934-0571 

Wood treatment plant owners and operators can face difficult issues when wood treating chemicals are detected in nearby soils, sediments and water.  Environmentally regulated compounds known as polycyclic aromatic hydrocarbons (PAH), pentachlorophenol, and copper naphthenate are useful for determining the origin of wood preservatives in the environment.  However, PAH are also released into the environment in the form of petroleum, fuels, automotive emissions, furnace smoke, smelting discharges, storm water runoff, forest fires, volcanic eruptions and other sources.  Sorting out the origin of PAH can pose vexing difficulties, especially in the absence of detailed purchasing and waste management records.  The differentiation of PAH from creosote assumes a greater degree of complexity when plant ownership changed over time and independent PAH generating industries resided near the wood treating plant.

Distinguishing the origin of PAH from multiple sources in the environment can be difficult.  The chemical signatures of natural, point and non-point PAH sources can be very similar.  This becomes an important issue when remediation is required at moderate to low PAH concentrations.  The effects of environmental weathering and matrix interferences in environmental media often confound the signature of various proximate sources.  Consequently, multiple lines of evidence and the creative use of alternative measurement techniques are required to isolate and distinguish among potential PAH sources.  Utilizing an environmental forensic approach is useful for clearly defining the extent a release and the allocation of cleanup costs. 

Several emerging environmental forensic methodologies have been reviewed and tested for identifying the sources of PAH materials in the environment generated by the manufacture of treated wood, gas, coke, and tar products in the presence of urban background and atmospheric fallout.  The analytical methods to be demonstrated include measurement of copper naphthenate, pentachlorophenol, alkylated PAHs and biomarkers by GC/MS, applications of organic petrology, and selective use of compound-specific isotope ratio mass spectrometry (GC/IRMS).  The interpretive techniques that will be discussed include chemical fingerprinting, diagnostic ratios, and organic petrography.

Experience in Dust Emissions Modeling of a Contaminated Soil Recycling Facility

Albert P. Free, P.E., CSP, LEP; M.Eng., Civil and Environmental Engineering, Vice President, Soil and Land Use Technology, Inc., 11609 Edmonston Road, Beltsville, MD 20705, Tel: 301-595-3783
Email: alfree@salutinc.com
William Roberts, Chief Technology Officer, Soil Safe Incorporated, 125 Stafford Drive, Suite 130, Wayne, PA 19087, Tel: 610-688-5636, Email: warolite@aol.com 
James L.W. Grant, MBA, Director of On-site Remediation Programs, Soil Safe Incorporated, 2700 Lighthouse Point East, Suite 402, Baltimore, MD 21224, Tel: 410-327-5753, Email: jgrant@soilsafe.com

Soil Safe Incorporated operates a soil recycling facility on top of the City of Salem, New Jersey’s closed municipal solid waste landfill. The facility accepts non-hazardous petroleum contaminated soils, processes the soil to stabilize the contamination, and generates materials that are being used to cap the closed landfill.

At the direction of the New Jersey Department of Environmental Protection, the authors performed air modeling to evaluate fugitive dust emissions from the site. The Environmental Protection Agency’s Industrial Source Complex (ISC3) air dispersion model was used to model the site. Emissions factors for the various potential emissions sources were calculated using the AP-42 criteria developed by the EPA’s Emission Factor and Inventory Group (EFIG). The site was modeled for a five-year period using available meteorological data.

Thirty-one separate potential emissions sources were input into the model. Fugitive dust concentrations were calculated for approximately 1,000 discrete receptor locations consisting of the property boundaries and a nine square kilometer grid. Hourly, daily and annual dust concentrations were analyzed at each receptor location.

The results of this modeling demonstrated that facility air quality was well within the limits established by the National Ambient Air Quality Standards (NAAQS) and were used to perform a health risk analysis for particulate, organic and inorganic contaminants in the soil. Contaminants of concern included dust (PM-10), polynuclear aromatic hydrocarbons, arsenic, beryllium, cadmium, nickel, lead, and zinc. The incremental health risk associated with the operations was calculated for these contaminants of concern. The results were then used to develop facility operating limits for processing contaminated soil containing the contaminants of concern.

Speciation as an Important Tool for Environmental Scientists

Hakan Gürleyük, Research Scientist, Frontier Geosciences, 414 Pontius Ave. N, Seattle, WA 98109, Tel: 206-622-6960, Fax: 206-22 6870,  Email: HakanG@FrontierGeosciences.com

Speciation analysis is defined as the separation and quantification of different oxidation states or chemical forms of a particular element. Interest and research in speciation analysis has increased exponentially with the realization that different forms of an element can have totally different properties which could result in differences in toxicity and mobility in the environment (e.g. Cr(III) vs. Cr(VI)). Therefore, speciation analysis is essential for predicting and modeling fate, risk, and effects while it’s a must have for designing custom - tailored treatment strategies. In our experience, speciation data is accepted by some regulators but there are no set laws or regulations on this matter. We believe that the lack of species-specific regulations is due to the absence of methods that can reliably measure the analytes of interest at the regulatory levels. While there are no available speciation methods for elements such as Mo, Mn, B, Se; for As and Cr, the methods available are either not selective enough or do not provide sufficiently low detection limits. In addition, most sophisticated analytical methods for the determination of an element’s speciation are “useless” if it cannot be assured that the species distribution in the sample remains unchanged between collection and analysis. Therefore, right preservation techniques should be used for the right matrix to ensure that the speciation information in the sample remains intact during shipping and storage until the analysis is performed. We have developed various methods for the speciation analysis of various elements (As, Se, Cr, Mo, Mn, B, I, and cyanides). These methods combine chromatographic separations with the detection power of ICP-MS to achieve detection limits between 1 and 10 ng/L (ppt) for most species. We will present various cases where these methods were used to make educated decisions for various environmental problems. 

Characterization of Soot Carbon and PAH Bioavailability in Aquatic Sediments At MGP Sites 

Edward F. Neuhauser, Niagara Mohawk Power Corporation, 300 Erie Blvd. W., Syracuse, NY  13202 Tel: 315-428-3355, Fax: 315-428-3549
Joseph P. Kreitinger, The RETEC Group, Inc., 1001 West Seneca Street, Suite 204, Ithaca, NY  14850 Tel: 607-277-5716, Fax: 607-277-9057
David V. Nakles, The RETEC Group, Inc., One Monroeville Center, Suite 1015, Monroeville, PA  15146 Tel: 412-380-0140, Fax: 412-380-0141
Steven B. Hawthorne, Energy and Environmental Research Center, University of North Dakota, 15 N. 23^rd Street, Grand Forks, ND  58203, Tel: 701-777-5256, Fax: 701-777-5181
Francis G. Doherty, AquaTOX Research, Inc., 1201 East Fayette Street, Syracuse, NY  13210, Tel: 315-479-1498, Fax: 315-479-1499
Charles A. Menzie, Menzie Cura & Associates, Inc., 1 Courthouse Lane, Suite 2, Chelmsford, MA  01824, Tel: 978-453-4300, Fax: 978-970-2791

Field data indicate that anthropogenic sources of combustion-derived black carbon (soot-like particles) in aquatic sediments may significantly affect the speciation and bioavailability of PAHs.  We hypothesized that at former gas manufacturing plants (MGPs), soot, coke and coal particulates may dominate the speciation of PAHs in aquatic sediments lowering the bioavailability of PAHs to aquatic life.  To test this hypothesis, the bioavailability of PAHs was measured by exposing the aquatic oligochaete, Lumbriculus variegatus, in laboratory bioassays to five freshwater sediments collected from an MGP site. The concentration of PAHs in worm tissue was compared to predictions using default equilibrium partitioning theory.  The measured concentration of total PAHs in worms was 80% lower in some samples than predicted.  The biota sediment accumulation factor (BSAF) for individual PAHs ranged from <0.001 to 2.6.  The characteristics of the organic carbon in each sample were determined using several different thermal combustion techniques.  The amount of black carbon (BC) ranged from 0.4% to 1.4% of the sediment on a dry weight basis, and 17% to 84% of the total organic carbon present in the sample.  The rapidly released PAH fraction determined by mild supercritical fluid extraction (SFE) ranged from 0.02 to 0.92 for individual PAHs.  Modified predictions of worm PAH uptake were made using equilibrium partitioning theory with and without adjustments for the rapidly available PAH fraction.  Graphical analysis of the error in predicting PAH uptake shows that the relationship between the SFE rapidly available fraction and the measured bioavailable fraction is a nonlinear function of a PAH property such as K_ow or aqueous solubility.  A survey of PAH bioavailability and the carbon characteristics of sediments at multiple MGP sites is on-going and the data available from that effort will also be presented and discussed.

Comparative Evaluation of Background Hydrocarbons in Sediments from Multiple Urban Waterways

Scott A. Stout, Ph.D., Allen D. Uhler, Ph.D., and Stephen Emsbo-Mattingly, M.S., Battelle Memorial Institute, 397 Washington St., Duxbury, MA, Tel: 781-934-0571, Fax: 781-934-2124

Environmental forensic and remedial investigations of hydrocarbon-contaminant urban sediments must recognize and define the ambient or ‘background’ conditions.  In most settings the ambient conditions arise from non-point source contamination associated with atmospheric fallout and urban runoff, collectively referred to as urban background.  In environmental forensic investigations involving hydrocarbons, e.g., polycyclic aromatic hydrocarbons (PAH), it is important to recognize the potential contribution from urban background as it may admix with other PAH point sources within a given waterway.  In remedial investigations of contaminated sediments, defining the relative influence of urban background is essential to distinguishing its contribution from that due to point sources requiring remediation.   In this study, the characteristics of hydrocarbons, including alkylated PAH distributions and concentrations, within sediments from numerous, well-studied urban waterways on both Coasts were evaluated and compared.   The collective features of sediments impacted by urban background are summarized.   Comparable data from some common components found within urban background (e.g., soot, used lubricating oils, etc.) are presented.

Molecular Characterization of Biogenic Hydrocarbons in Terrestrial Soils

Richard M. Uhler, Lyle G. Roberts, Bryan Murphy, and Scott A. Stout, Battelle Memorial Institute, 397 Washington Street, Duxbury MA 02332, Tel: 781-934-0571, Fax: 781-934-2124

Upon solvent extraction by typical methods (e.g., EPA Method Series 3500) the naturally-occurring organic matter, or biogenics, in some soils yields hydrocarbons and non-hydrocarbons (i.e., polars) within the same diesel- and residual-boiling ranges of anthropogenic hydrocarbon contaminants (e.g., DRO and RRO due to petroleum).   Thus, it is now common to perform some cleanup (fractionation) of whole soil extracts (e.g., EPA Method Series 3600) in an effort to minimize this by removing the polar components of soil biogenics.  However, some biogenics are not removed by alumina or silica gel cleanup and thereby, their mass can still be confused with or attributed to anthropogenic contaminants (e.g., TPH or EPH).  Avoiding such confusion is critical in remedial investigations or phytoremediation projects in terrestrial soils.

In this paper, the molecular character of alumina-cleaned, solvent extracts from (1) live deciduous leaves, (2) live herbaceous leaves, (3) dead mixed-leaf litter, and (4) soils containing these plant materials from a variety of terrestrial habitats are investigated.   The alumina-cleaned extracts (combined aliphatic and aromatic hydrocarbon fractions) for 1000’s of samples were analyzed by gas chromatography-flame ionization detection (GC/FID) and the extractable TPH (i.e., EPH_total) concentrations determined according to EPA Method 8105.   The statistics for large (>1000) populations of extractable TPH data from each group of materials analyzed are reported.    The chromatographic “fingerprints” of commonly contain the expected odd-carbon dominated n-alkanes in the C₂₅ to C₃₃ range that are attributed to terrestrial plant leaf waxes.   However, many other biogenics hydrocarbons were also recognized.   Selected alumina-cleaned extracts containing these were analyzed by gas chromatography-mass spectrometry (GC/MS) operated in the full scan mode for molecular characterization of the biogenics hydrocarbons.   Mass spectral analysis revealed a variety of iso- and anteiso-alkanes, unsaturated aliphatic hydrocarbons and aromatic hydrocarbons with sesqui- and triterpene skeletons.

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