B51B-0360
Water Environment of Kochi - Risk and Impacts Assessment
The southwest coast of India is known for its maritime tropical climate which encompasses the Summer Monsoon and resultant land runoff. The Kochi region receives vast amount of rainfall in a short spell of four months (June-September) and for the given terrain characteristics, approximately 70% escapes to the Arabian Sea. The dry season (January-May) is deficit in water resources when the demands are equally high. Superimposed on this natural cycle, the land use changes, alterations in agricultural pattern, deforestation and water regulation along with ill effects of urbanization and industrialization has lead to grave negative impacts in the water environment. A vivid picture is drawn on the environmental setting of this region placing due emphasize on water resources, water quality and community services and resource management versus impacts. Critical areas such as balancing water surplus against deficit, quality maintenance against health scenario and issues in policy making for the water regime in Kochi region is assessed in terms of embedded risks.
B51B-0361
Integrated Impacts of environmental factors on the degradation of fumigants
Volatilization of fumigants has been concerned as one of air pollution sources. Fumigants are used to control nematodes and soil-born pathogens for a pre-plant treatment to increase the production of high-cash crops. One of technologies to reduce the volatilization of fumigants to atmosphere is to enhance the degradation of fumigants in soil. Fumigant degradation is affected by environmental factors such as moisture content, temperature, initial concentration of injected fumigants, and soil properties. However, effects of each factor on the degradation were limitedly characterized and integrated Impacts from environmental factors has not been described yet. Degradation of 1,3- dichloropropene (1,3-D) was investigated in various condition of temperatures (20-60 „aC), moisture contents (0 \ˇV 30 %) and initial concentrations (0.6 \ˇV 60 mg/kg) with Arlington sandy loam soil. Abiotic and biotic degradation processes were distinguished using two sterilization methods with HgCl2 and autoclave and impacts of environmental factors were separately assessed for abiotic and biotic degradations. Initially, degradation rates (k) of cis and trans 1,3-D isomers were estimated by first-order kinetics and modified depending on impacts from environmental factors. Arrhenius equation and Walker's equation which were conventionally used to describe temperature and moisture effects on degradation were assessed for integrated impacts from environmental factors and logarithmical correlation was observed between initial concentrations of applied fumigants and degradation rates. Understanding integrated impacts of environmental factors on degradation will help to design more effective emission reduction schemes in various conditions and provide more practical parameters for modeling simulations.
B51B-0362
Speciation of Lead in Airborne Particulate Matter in El Paso, TX, by X-ray Absorption Spectroscopy
X-ray absorption spectroscopy indicates that lead humate is the dominant species of lead in airborne particulate matter in El Paso, Texas. Lead humate is a stable complex of Pb with the humus component of soil, and is the major Pb species that we found in El Paso soils. Because Pb-contaminated soil is the only significant source of lead humate, re-entrainment of such soil likely provides most of the lead found in particulate matter in the local atmosphere. Elimination of leaded gasoline dramatically decreased lead in particulate matter in the US over the last three decades. Consequently, there was a significant decrease in blood lead levels. Nonetheless, because Pb is such a potent neurotoxin for children, further reductions in airborne lead levels are being called for. Our result can inform this regulatory debate. We examined a total of 20 TSP (Total Suspended Particulate) samples collected at 3 stations in various seasons in 1999 and 2005. Low lead concentrations in the particulate matter and intimately associated filter medium compromised data quality. Six samples proved suitable for standard EXAFS analysis, and XANES analysis was possible with all 20. Comparisons of the XANES and EXAFS of our air samples indicated homogeneity of speciation with regard to geography, season, and year. The XANES and EXAFS spectra were a close match to those of both a lead humate standard and a typical El Paso soil sample with an elevated lead level. X-Ray absorption spectroscopy experiments were conducted at the Stanford Synchrotron Radiation Laboratory on beam lines 7-3, 10-2, and 11-2. Spectra were collected at the Pb L-III absorption edge in fluorescence mode using a 13-element or a 30-element Ge solid-state detector. This publication was made possible by grant numbers 1RO1-ES11367 and 1 S11 ES013339-01A1 from the National Institute of Environmental Health Sciences (NIEHS), NIH. Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the NIEHS, NIH. Partial travel support provided by SSRL-DOE-UTEP Gateway Program.
B51B-0363
Data quality assessment of direct counts of virus-sized microsphere in water samples by epifluorescence microscopy
Fluorescent microsphere has been used as pathogen surrogates in pathogen transport studies. A common technique, direct counting by epifluorescence microscopy, for the enumeration of virus- and bacteria-sized microsphere has been applied in laboratory and field studies. However, few studies have focused on factors ensuring precise and accurate measures. Factorial experiment and two-way ANOVA with repeated measures performed to investigate the factors affecting the data quality. The evaluated factors were 1) the density of microspheres in each field and 2) the total number of counts in an enumeration. Two parameters, relative standard deviation and percent error, were used to assess methodological precision and accuracy. In addition, two water compositions with different ionic strength, i.e., calcite-saturated artificial groundwater (AGW) and deionized water (DIW) was used for assessing the effect of ionic strength and presence of precipitates. A standard method was used to prepare slides and enumerate microspheres, with particular care to randomly select fields for counting. As a result of visual observations of the slides, undulation in the filter membrane, bubble entrained in the mounting medium, and the presence of precipitates that form in AGW create biases in microsphere enumeration. As result of statistical assessment, microsphere density was found to be critical for ensuring methodological precision, whereas the total number of microspheres counted was essential to ensuring methodological accuracy. The results suggested that to minimize variability using the field approach, the enumeration of at least 350 microspheres and 25–40 microspheres field-1 is necessary.
B51B-0364
Biogeochemical Reactions Under Simulated Europa Ocean Conditions
Galileo data have demonstrated the probable presence of a liquid water ocean on Europa, and existence of salts and carbon dioxide in the satellite's surface ice (e.g., Carr et al., 1998; McCord et al., 1999, Pappalardo et al., 1999; Kivelson et al., 2000). Subsequently, the discovery of chemical signatures of extinct or extant life in Europa's ocean and on its surface became a distinct possibility. Moreover, understanding of Europa's potential habitability is now one of the major goals of the Europa Orbiter Flagship mission. It is likely, that in the early stages of Europa's ocean formation, moderately alkaline oceanic sulfate-carbonate species and a magnetite-silicate mantel could have participated in low-temperature biogeochemical sulfur, iron and carbon cycles facilitated by primitive organisms (Zolotov and Shock, 2004). If periodic supplies of fresh rock and sulfate-carbonate ions are available in Europa's ocean, then an exciting prospect exists that life may be present in Europa's ocean today. In our laboratory, we began the study of the plausible biogeochemical reactions under conditions appropriate to Europa's ocean using barophilic psychrophilic organisms that thrive under anaerobic conditions. In the near absence of abiotic synthetic pathways due to low Europa's temperatures, the biotic synthesis may present a viable opportunity for the formation of the organic and inorganic compounds under these extreme conditions. This work is independent of assumptions regarding hydrothermal vents at Europa's ocean floor or surface-derived oxidant sources. For our studies, we have fabricated a high-pressure (5,000 psi) reaction vessel that simulates aqueous conditions on Europa. We were also successful at reviving barophilic psychrophilic strains of Shewanella bacterium, which serve as test organisms in this investigation. Currently, facultative barophilic psychrophilic stains of Shewanella are grown in the presence of ferric food source; the strains exhibiting iron reduction capability will be later selected and used to facilitate biogeochemical reduction of iron under simulated temperature and pressure of Europa's ocean. The results of this work will enable us to ascertain whether Europa‘s cold, high-pressure ocean is capable of supporting life. In addition, the data from this study will help in generating a list of organic and inorganic target molecules for future remote sensing and in situ exploration missions.
B51B-0365
A Natural Niche of Dehalococcoides Species
Dehalorespirers such as Dehalococcoides have been found to dechlorinate a wide variety of chlorinated organic compounds from anthropogenic sources. Several of these compounds are persistent, bioaccumulative, and toxic, and low cost methods of remediation are of critical importance. One major challenge of remediation of these compounds is the ability to successfully stimulate the growth of these organisms using safe alternative electron acceptors. Recently, large quantities of natural organochlorines have been found to exist in nature, and it is plausible that these natural compounds may be capable of stimulating the growth of dehalorespirers. This research tests the hypothesis that dehalorespirers are a natural component of uncontaminated ecosystems and that their presence is linked to the presence of natural chlorinated organic compounds, which they presumably respire. Thirty two individual soil samples and one soil core were collected from a variety of undisturbed, pristine ecosystems. The DNA of the bacteria in these soil samples was extracted and the presence and absence of Dehalococcoides-like species was determined. All samples contained Dehalococcoides-like species, despite the fact that the samples were from pristine locations. Fluorescent in situ hybridization and sequencing was used to confirm the presence of Dehalococcoides-like organisms in the samples. Quantitative real-time polymerase chain reaction has been used to quantify the numbers of Dehalococcoides-like species in the samples and in a soil core. These numbers will be correlated with the quantity of chlorinated organic matter in the samples. It appears that dehalorespirers are present in environments in which xenobiotic chlorinated compounds are absent, therefore indicating that dehalorespirers might play a role in the natural terrestrial chlorine cycle.
B51B-0366
The Ecology and Trace Metal Geochemistry of Living Benthic Foraminifera in the Venice Lagoon, Italy
The ecology and trace metal geochemistry of living benthic foraminifera in the Venice Lagoon was assessed as part of an ongoing international effort examining biological and biogeochemical responses to environmental changes in Lagoonal sediments (SIOSED). The "SIOSED" project is part of a comprehensive effort to support the integrated management of Venice Lagoon sediments and ecosystems promoted by the Venice Water Authority through its Concessionary, Consorzio Venezia Nuova. Living (Rose Bengal-stained) benthic foraminiferal assemblages (greater than 150 microns) were dominated by Ammonia tepida, Haynesina germanica, and Quinqueloculina sp. Differences in spatial and vertical distribution patterns of these foraminiferal taxa appear to reflect differences in the availability of contaminants. Laser ablation ICPMS analyses of Mn, Mg, Zn, Pb, As, Cd, Al, and V in foraminiferal calcite showed that some trace element concentration ratios, particularly zinc/calcium, varied between sites and between species. Differences in trace metal signatures from foraminifera living at different sites may be related to bioavailable pollutant concentrations and/or to redox processes that release adsorbed trace metals from reducible phases (e.g., iron oxides). Results provide calibration data for contaminant proxies of spatial and temporal environmental differences.
B51B-0367
Process-Based Modeling of Constructed Wetlands
Constructed wetlands (CWs) are widespread facilities for wastewater treatment. In subsurface flow wetlands, contaminated wastewater flows through a porous matrix, where oxidation and detoxification phenomena occur. Despite the large number of working CWs, system design and optimization are still mainly based upon empirical equations or simplified first-order kinetics. This results from an incomplete understanding of the system functioning, and may in turn hinder the performance and effectiveness of the treatment process. As a result, CWs are often considered not suitable to meet high water quality-standards, or to treat water contaminated with recalcitrant anthropogenic contaminants. To date, only a limited number of detailed numerical models have been developed and successfully applied to simulate constructed wetland behavior. Among these, one of the most complete and powerful is CW2D, which is based on Hydrus2D. The aim of this work is to develop a comprehensive simulator tailored to model the functioning of horizontal flow constructed wetlands and in turn provide a reliable design and optimization tool. The model is based upon PHWAT, a general reactive transport code for saturated flow. PHWAT couples MODFLOW, MT3DMS and PHREEQC-2 using an operator-splitting approach. The use of PHREEQC to simulate reactions allows great flexibility in simulating biogeochemical processes. The biogeochemical reaction network is similar to that of CW2D, and is based on the Activated Sludge Model (ASM). Kinetic oxidation of carbon sources and nutrient transformations (nitrogen and phosphorous primarily) are modeled via Monod-type kinetic equations. Oxygen dissolution is accounted for via a first-order mass-transfer equation. While the ASM model only includes a limited number of kinetic equations, the new simulator permits incorporation of an unlimited number of both kinetic and equilibrium reactions. Changes in pH, redox potential and surface reactions can be easily incorporated. The model has been successfully validated using published experimental data. Two measurement campaigns conducted on a CW facility from New South Wales, Australia have been used. The first set of data was used to calibrate the model, while the second trial, recorded two months later with a different loading rate, was used to identify possible changes in the wetland functioning. Further to this, a sensitivity analysis was performed to identify the main parameters controlling the system. As expected, the parameter with largest impact is oxygen mass-transfer rate.
B51B-0368
Atmospheric Rawinsonde and Pigeon Release Data Implicate Infrasound as the Long- Range Map Cue in Avian Navigation
Pigeons ( Columba livia) and other birds released from distant familiar and unfamiliar sites generally head in the homeward (loft) direction, but often vanish from view or radio contact consistently off the exact homeward bearing. At some sites the deviation can be a significant and stable amount, while at other sites birds can appear to become completely lost and depart in random directions. These deviations or biases can change from hour to hour, day to day, and year to year, but have not, over the last ~50 years of intensive research, been related to any atmospheric factor. They are, however, still considered to reflect significant irregularities in the pigeons' "map" function. Celestial and geomagnetic "compasses" have been shown to orient avian flight, but how pigeons determine their location in order to select the correct homeward bearing remains controversial. At present the debate is primarily between workers advocating an olfactory "map" and those advocating variations in the direction and intensity of the geomagnetic field as map functions. Alternatively, infrasonic cues can travel 1000s of km in the atmosphere with little attenuation, and can be detected in the laboratory by pigeons at frequencies down to 0.05 Hz. Although infrasound has been considered as a navigational tool for homing and migratory birds, little supporting evidence of its use has been found. Infrasonic ray paths in the atmosphere are controlled primarily by temperature and secondarily by wind. Assuming birds use infrasonic cues, atmospheric conditions could cause the perplexing changes (both geographic and temporal) observed in the mean vanishing bearings (MVBs) of pigeons released from experimental sites. To test for correlations between MVBs and tropospheric conditions, release data collected by the late W.T. Keeton between 1968 and 1980 from around the Cornell University lofts in upstate NY are compared to rawinsonde data from stations near Buffalo and Albany. For example, birds released at the Jersey Hill fire tower 132 km W of Ithaca most often departed at random. A singular exception was August 13, 1969; the Cornell birds released at Jersey Hill that day vanished in a tight cluster to the NE and arrived home the same day. Birds released the next day vanished randomly, and no evidence of what changed at Jersey Hill on August 13 has previously been presented. What did change, compared to the other release dates, were the speed and direction of the upper tropospheric winds over western NY. The jet stream winds are commonly from the SW and oppose infrasonic signals coming from the E, presumably near Ithaca, potentially creating an infrasonic "dead zone" at Jersey Hill. On August 13, 1969, the jet stream winds extraordinarily dropped sharply in speed and reversed direction to come from the NE. By the next day the upper tropospheric winds had returned to their normal westerly pattern explaining the Cornell birds' disorientation just one day later. This and several other examples will be presented indicating that infrasonic cues are a likely candidate for the long-range map cue in avian navigation.
B51B-0369
Numerical Simulation of the Anaerobic Transformation of Tetrachloroethene to cis-Dichloroethene in a Continuous Flow Aquifer Column
The anaerobic reductive dechlorination of tetrachloroethene (PCE) to cis-dichloroethene (c-DCE) in a laboratory column study was numerically simulated and compared with experimental observations. The column study was conducted with continuous flow and injection of PCE in synthetic groundwater. The column was packed with aquifer solids from the Hanford DOE site and bioaugmented with the Evanite (EV) dechlorinating enrichment culture. After the column was bioaugmented and fed lactate as an electron donor, c-DCE concentrations in the column effluent exceeded the influent PCE concentration. This high c-DCE concentration resulted from enhanced PCE desorption and transformation. A 1-D reactive transport model was developed that included the processes of dispersion, advection, rate-limited sorption and desorption, reductive dechlorination kinetics with competitive inhibition and microbial growth and decay. The model was validated by mass balances, comparisons with analytical solutions and batch kinetic models. Previously determined kinetic and inhibition constants for the EV culture of Yu and Semprini (2004) were input into the model simulations. Initial biomass concentration was assumed to be exponentially distributed along the column. The sorption parameters including the aquifer: water distribution coefficients (Kds) and first-order mass transfer coefficients for PCE, trichloroethene (TCE), and c-DCE were determined in batch laboratory studies. The system of model equations was solved numerically using COMSOL 3.3, which employs finite-element methods. The reactive transport model successfully simulated the initial results of continuous flow column experiment. The increase in c-DCE above the influent PCE concentration was simulated and TCE was shown not to accumulate in the column effluent. The simulations showed that microbial kinetic values generated in previous studies and the sorption parameters generated in batch tests, when used in a transport model, did a reasonable job estimating PCE, TCE, and c-DCE concentration histories in the column effluent. Currently a sensitivity analysis is being performed to better understand why some differences, such as the more rapid breakthrough of c-DCE, was observed in the experimental data, but not in the model simulations.
B51B-0370
Geochemical fate of arsenic in swine litter
Swine diet is often supplemented by organoarsenicals, such as roxarsone to treat diseases and to promote growth. Recent data reported roxarsone degradation under anaerobic conditions in poultry litter, but no such data exist for swine wastes typically stored in unprotected lagoons in concentrated animal feeding operations (CAFOs). However, serious environmental health risk may arise upon significant arsenic (As) release into solution. The problem may be exacerbated under certain environmental conditions where organoarsenicals, such as roxarsone transform into the more toxic inorganic As, posing serious health risk to the surrounding ecosystem. The objective of this study were to analyze swine wastes collected from 19 randomly selected CAFOs in the USA for As concentrations, and to determine the geochemical fate of As in the swine waste suspensions. Swine wastes were analyzed for total-recoverable, total soluble, and water-extractable As, which were measured by ICP-MS. Speciation of As was performed following a well-established hyphenated technique using HPLC- ICPMS. Swine waste suspensions differed in solids contents; thus, the particulate matters with varying As concentrations were spiked with roxarsone and incubated under dark/light and aerobic/anaerobic conditions. Findings show the prevalence of inorganic As [As(V)] in swine waste suspension solutions. Roxarsone underwent degradation to both organoarsenicals, such as p-ASA, as well as inorganic arsenate and to a number of unidentified metabolites. Roxarsone degradation kinetics was influenced by the solids content and the air conditions (anaerobic/aerobic) of the swine waste suspensions. Maximum degradation rates were observed under anaerobic conditions, in suspensions which were low in solids content. Roxarsone degradation was primarily microbially-mediated, but in certain cases abiotic degradation was also observed, which were significantly slower.
B51B-0371
A Comparison of the Soil Bioload of Mars Analog Sites Using a Novel Life Detection Instrument.
In this presentation we compare the microbial bioload at Mars Analog Sites, such as the Moab, Mojave, and Atacama Deserts as well as high altitude volcanic environments. A novel technique using intrinsic fluorescence for life detection was implemented in-situ to quantify total soil biomass. Soil samples were collected to compare in-situ techniques with traditional microbial assays, such as culturing. The Mars Analog sites differ in soil bioload, but show similarities in microbial patchiness distribution. In addition to the microbial work we also describe the novel instrument used to detect and quantify the total soil bioload.
B51B-0372
Wetlands for Wastewater: a Visual Approach to Microbial Dynamics
The complex character of distillery wastewater comprises high concentrations of sugars, lignins, hemicelluloses, dextrans, resins, polyphenols and organic acids which are recalcitrant to biodegradation. Microorganisms play a key role in the production and degradation of organic matter, environmental pollutants, and cycling of nutrients and metals. Due to their short life cycles microbes respond rapidly to external nutrient loading, with major consequences for the stability of biological systems. We evaluated the feasibility of wetlands to treat winery and distillery effluents in experimental systems based on constructed wetlands, including down-scaled on-site distillery wetlands, small-scale controlled greenhouse systems, and bench-scale mesocosms. Chemical, visual and molecular fingerprinting (t-RFLP) techniques were applied to study the dynamics of planktonic and attached (biofilm) communities at various points in wetlands of different size, retention time and geological substrate, and under influence of shock nutrient loadings. Variable- Pressure Scanning Electron Microscopy (VP-SEM) was applied to visualize microbial colonization, morphotype diversity and distribution, and 3D biofilm architecture. Cross-taxon and predator-prey interactions were markedly influenced by organic loading, while the presence of algae affected microbial community composition and biofilm structure. COD removal varied with geological substrate, and was positively correlated with retention time in gravel wetlands. Planktonic and biofilm communities varied markedly in different regions of the wetland and over time, as indicated by whole-community t-RFLP and VP-SEM. An integrative visual approach to community dynamics enhanced data retrieval not afforded by molecular techniques alone. The high microbial diversity along spatial and temporal gradients, and responsiveness to the physico-chemical environment, suggest that microbial communities maintain metabolic function by modifying species composition in response to fluctuations in their environment. It seems apparent that microbial community plasticity may indeed be the distinguishing characteristic of a successful wetland system.
B51B-0373
2D Process-based Microbialite Growth Model
A 2D process-based microbialite growth model (MGM) has been developed that integrates the coupled effects of the microbialite growth and sediment distribution within a two-dimensional cross-section of a subaqueous bedrock profile. Sediment transport is realized through particle erosion and deposition that are a function of local wave energy which is computed on the basis of linear wave theory. Surface-normal microbialite growth is directly correlated to light intensity, which is computed for every point of the microbialite surface by using a Henyey- Greenstein-type relation for scattering and the Beer's Law for absorption in the water column. Shadowing effects by surrounding obstacles and/or overlying sediment are also considered. Sediment particles can be incorporated into the microbialite framework if growth occurs in the presence of sediment. The resulting meter-size microbialite constructs develop morphologies that correspond well to natural microbialites. Furthermore, changes of environmental factors such as light intensity, wave energy, and bedrock profile result in morphological variations of the microbialites that would be expected on the basis of the current understanding of microbialite growth and development.
B51B-0374
Resolving the Unresolved Complex Mixtures of Hydrothermal Petroleum Using Comprehensive Two-Dimensional Gas Chromatography - Time of Flight Mass Spectrometry
Within hydrothermal systems sedimentary organic matter can be altered by high temperature fluids resulting in the generation of petroleum. These hydrothermal petroleums are compositionally similar to conventional, basin- formed petroleum, with the exception that they often contain substantial mixtures of coeluting organic compounds, which are difficult to resolve by traditional gas chromatographic methods. The coelution of these compounds produces a rapidly rising baseline in gas chromatogram that is referred to as an unresolved complex mixture (UCM). Little is known about these UCMs or why and how they form. In this study we analyzed the apolar fractions of four hydrothermal petroleum samples from the Middle Valley, Juan de Fuca Ridge and Escanaba Trough, Gorda Ridge in the NE Pacific Ocean and the Guaymus Basin, Gulf of California using comprehensive two-dimensional gas chromatography-Time of Flight Mass Spectrometry (GC×GC-ToFMS). The GC×GC-ToFMS chromatograms of these samples elucidate two hydrocarbon subsets. The first subset consists of commonly defined hydrocarbon series such as n-alkanes, alkylcyclohexanes, alkylbenzenes, naphthalenes, tricylic terpanes, steranes, and hopanes. The second subset is dominated by compounds forming the UCM. These compounds form a continuous series of configurational isomers that become increasingly aromatic at higher molecular weights. The UCMs of the hydrothermal petroleum samples vary as a function of the relative intensity, number, and molecular weight range of the contributing configurational isomers. The subset appears to represent areas of mass gain that overprint the first subset in the GC×GC-ToFMS chromatogram. This gain likely reflects an exogenous input or the accumulation of primary organic matter that underwent extensive dehydrogenation and dealkylation. Variation between the second hydrocarbon sample subsets is likely caused by different thermal gradients within the pyrolytic regimes, gaseous solubilization, hydrodynamic alteration from multi-component fluids, and post-depositional alteration from biodegradation and water-washing.
B51B-0375
DISTRIBUTION OF LANTHANIDES IN MEDITERRANEAN COASTAL WATER
Distribution and behaviour of the whole lanthanide series and yttrium in both seawater column and suspended particulate matter were investigated in coastal water located in the Central Mediterranean Sea. An area characterized by high anthropic pressure, atmospheric fallout and river input due to drainage of little local watersheds was selected. Water masses were discriminated with respect to both surrounding and depth and in relation to the processes occurring at the solid-liquid interface. We found that yttrium and Rare Earth Elements in the labile fraction of the suspended particulates result from the mixing between lithogenic material from the Sicilian basin and detrital material of Sahara origin. Y/Ho and Ce/La ratios, Ce anomalies, shape and amplitudes of tetrad effects calculated in both dissolved phase and suspended matter indicates that heavier Rare Earth (from Dy to Lu) mainly occur as organic complexes in near shore waters whereas, light and intermediate Rare Earths (From La to Ho) in the outer waters are ruled by scaveging processes onto surface of suspended matter. The behaviour of these trace elements is explained in terms of lanthanides sorption into Mn-Fe oxyhydroxide surfaces and under solution complexation. In particular, for deep water layers the found low apparent distribution coefficients for the heaviest REE and high dissolved organic matter concentration indicate surface complexation processes according to an outer sphere coordination mechanism.
B51B-0376
Laboratory Protocol for Measuring the Bioaccumulation of Mercury by Earthworms
Protocol was developed for a series of laboratory tests to determine if Canadian earthworms ( Lumbricus terrestris) can hyperaccumulate mercury from the soil in which they live. Two batches of 300 hundred worms each were measured for mercury uptake by establishing 3 populations (one control and two of known contamination). Populations were sampled every two weeks. Worm lengths were measured as an indicator of worm age and health. Worm tissue was processed by a modified EPA Method 7470 consisting of freeze drying, vacuum extraction, oxidation and acid extraction of the mercury. Each sample needed 2.000 g dry weight of worm tissue required 5 to 6 worms to be homogenized. Mercury concentration in the extraction fluid was measured by a CETAC M-6100 cold vapor mercury analyzer with an ASX-400 Autosampler having a method detection limit of 0.05 ppb. QA/QC activities such as calibration of instrumentation, spike samples, blank samples, reagent control samples, triplicate samples, and standard samples ensure acurate and precise measurements of mercury levels in tissue samples.
B51B-0377
Modeling the Emergent Impacts of Harvesting Acadian Forests over 100+ Years
Harvesting strategies and policies for Acadian forest in Nova Scotia, Canada, presently are set using Decision Support Models (DSMs) that aim to maximize the long-term (>100y) value of forests through decisions implemented over short time horizons (5-80 years). However, DSMs typically are aspatial, lack ecological processes and do not treat erosion, so the long-term (>100y) emergent impacts of the prescribed forestry decisions on erosion and vegetation in Acadian forests remain poorly known. To better understand these impacts, we created an equation-based model that simulates the evolution of a ≥4 km2 forest in time steps of 1 y and at a spatial resolution of 3 m2, the footprint of a single mature tree. The model combines 1) ecological processes of recruitment, competition, and mortality; 2) geomorphic processes of hillslope erosion; 3) anthropic processes of tree harvesting, replanting, and road construction under constraints imposed by regulations and cost/benefit ratio. The model uses digital elevation models, parameters (where available), and calibration (where measurements are not available) for conditions presently found in central Cape Breton, Nova Scotia. The model is unique because it 1) deals with the impacts of harvesting on an Acadian forest; and 2) vegetation and erosion are coupled. The model was tested by comparing the species-specific biomass of long-term (40 y) forest plot data to simulated results. At the spatial scale of individual 1 ha plots, model predictions presently account for approximately 50% of observed biomass changes through time, but predictions are hampered by the effects of serendipitous "random" events such as single tree windfall. Harvesting increases the cumulative erosion over 3000 years by 240% when compared to an old growth forest and significantly suppresses the growth of Balsam Fir and Sugar Maple. We discuss further tests of the model, and how it might be used to investigate the long-term sustainability of the recommendations made by DSMs and to better understand the relationship between vegetation, erosion, and forest management strategies.
B51B-0378
Linking water quality to water quantity: Integration of disturbance variables such as phytoplankton and turbidity into the management strategies of drinking water reservoirs
So far, seasonal management strategies for water withdrawal from drinking water reservoirs in Germany are based on the hydrological regime and use Monte-Carlo-simulations in order to provide recommendations with certain probability thresholds. Long-term experience on the annual development and composition of phytoplankton is used for ad-hoc adjustments in case of unexpected events. In the framework of the project INTEGTA ('Integrated management of reservoirs') knowledge on the biological and chemical freshwater ecosystem will be integrated into the widely used management system TALSIM. On the one hand, field studies on the reservoir system Klingenberg-Lehnmuehle are carried out in order to investigate the seasonal development and the dispersion of flood events in the major drinking water supply of Dresden, Saxony. The system consists of two closely linked reservoirs which are connected to other water storages so that many possibilities for water supply exist. In the year 2007, an early hot spring and lower than average precipitation resulted in a summerly water deficiency in Klingenberg reservoir which was met with increased supply with a time lag of one month. Though the inflowing water was of high quality and low temperature, the quality of the raw water could not be stabilized on the desired level and caused the request for an administrative fine. Thus, 2007 can be taken as a good example for studying the effect of delayed management activities. On the other hand, simulations by the coupled hydrodynamical ecological model SALMO will provide the basis to include water quality predictions into the decision system for the reservoir. Hydrological scenarios from the decision support system TALSIM are used as boundary conditions for the water quality model so that consistent predictions for the development of the water quantity and quality are derived. The output of the simulations are statistically analyzed with respect to (i) securing a sufficient water volume, (ii) increase/decrease of phytoplankton biomass, (iii) shifts in the phytoplankton community and (iv) increase/decrease of oxygen deficiency. These are transformed into management rules that can be included in TALSIM. The hydrological scenarios are designed in order to cover a wide range of meteorological situations including changes in the climatic conditions. Thus, the system will allow for the consideration of water quality issues under extreme events such as droughts and floods as well as under conditions of climate change.
B51B-0379
Preliminary analysis of a metals-contaminated brownfield: Palmerton, PA
Palmerton, PA was the site of zinc smelting for most of the 20th century, and the resulting airfall deposits of zinc, cadmium, lead, and arsenic, led to the destruction of a forest ecosystem along the neighboring Kittatinny Ridge and metals contamination in the town and surrounding area. Preliminary results from analysis of soil samples from the site of one of the smelting plants provides a baseline for the chemical distribution of metals as well as an indication of the time scale of dissipation of soil contamination since the smelter was shut down in the 1980's. An accurate and representative sampling of soil metal concentrations on the site was planned using a 100 meter grid and the identification of areas of concern using historical site data collected during a phase 1 investigation. Field sampling locations were locating using GPS enabled portable field computers equipped with ArcMap and a georeferenced set of digital aerial photographs and arc vector boundaries. Concentrations of metals were analyzed in the field using a portable x-ray fluorescence analyzer (Innov-X Systems). Analyses of samples from 141 shallow soil pits had zinc concentrations up to 95 mg/kg, with a mean value of 14 mg/kg. Lead concentrations in the same soils had concentrations ranging up to 250 mg/kg, with a mean value of 72 mg/kg. Continued sampling and digestion of soils is underway to validate and compare the field x-ray fluorescence technique to approved United States Environmental Protection Agency laboratory soil digestion techniques. An investigation of the contamination of soils at distances away from the field site can ascertain if any residual metal contamination exists and if strategies should be developed to mitigate incorporation of metals into the surface ecosystem, or if dissipation in recent decades has rendered baseless any community concerns of harmful metals concentrations.
B51B-0380
Microbial Biomass and Community Structure of a Stromatolite from an Acid Mine Drainage System in Western Indiana
Lipids extracted to determine the microbial biomass and community structure of an Fe-rich stromatolite from acid mine drainage (AMD) at the Green Valley coal mine site (GVS) in western Indiana correlate well with layers in the laminated stromatolite. The biomass of the top layer of the stromatolite was dominated by phototrophic organisms constituting 83% of the total biomass. Biomass of the lower layers was dominated by prokaryotic microorganisms. The presence of terminal methyl-branched fatty acids and mid methyl-branched fatty acids suggests the presence of Gram-positive and sulfate-reducing bacteria, respectively. Fungi appear to also be an important part of the AMD microbial communities as suggested by sterol profiles and the presence of polyunsaturated fatty acids. Hydroxy fatty acids and C19 cyclopropane fatty acids were also detected and likely originated from acid-producing, acidophilic bacteria. The presence of Archaea is indicated by abundant phospholipid ether-linked isoprenoid hydrocarbons (phytane and phytadienes). The AMD Fe-rich stromatolites at GVS, thus, appear to be formed by interactions of microbial communities composed of all three domains of life; Archaea, Bacteria, and Eukarya. Identification of microeukaryote-dominated stromatolites verifies the prominent role these organisms play in the formation and preservation of these structures. In addition, the production of oxygen through photosynthesis by these organisms in AMD systems may be important for retrodicting the interaction of microbial communities in Precambrian environments in the production of microbially mediated sedimentary structures and oxygenation of Earth's early atmosphere.