Jana Meierdierks*, Christiane Zarfl, Barbara Beckingham and Peter Grathwohl*,
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引用次数: 1
Abstract
Long-term accumulation in the soils of ubiquitous organic pollutants such as many polycyclic aromatic hydrocarbons (PAHs) depends on deposition from the atmosphere, revolatilization, leaching, and degradation processes such as photolysis and biodegradation. Quantifying the phase distribution and fluxes of these compounds across environmental compartments is thus crucial to understand the long-term contaminant fate. The gas-phase exchange between soil and atmosphere follows chemical fugacity gradients that can be approximated by gas-phase concentrations, yet which are difficult to measure directly. Thus, passive sampling, measured sorption isotherms, or empirical relationships to estimate sorption distribution have been combined in this study to determine aqueous (or gas) phase concentrations from measured bulk concentrations in soil solids. All these methods have their strengths and weaknesses but agree within 1 order of magnitude except for ex situ passive samplers employed in soil slurries, which estimated much lower concentrations in soil water and gas likely due to experimental artifacts. In field measurements, PAH concentrations determined in the atmosphere show a pronounced seasonality with some revolatilization during summer and gaseous deposition during winter, but overall dry deposition dominates annual mean fluxes. The characteristic patterns of PAHs in the different phases (gas phase, atmospheric passive samplers, bulk deposition, and soil solids) confirm the expected compound-specific distribution pattern and behavior. Since revolatilization fluxes in summer are only minor and wet and dry deposition is ongoing, our results clearly show that the PAH loads in topsoils will continue to increase.
期刊介绍:
ACS Environmental Au is an open access journal which publishes experimental research and theoretical results in all aspects of environmental science and technology both pure and applied. Short letters comprehensive articles reviews and perspectives are welcome in the following areas:Alternative EnergyAnthropogenic Impacts on Atmosphere Soil or WaterBiogeochemical CyclingBiomass or Wastes as ResourcesContaminants in Aquatic and Terrestrial EnvironmentsEnvironmental Data ScienceEcotoxicology and Public HealthEnergy and ClimateEnvironmental Modeling Processes and Measurement Methods and TechnologiesEnvironmental Nanotechnology and BiotechnologyGreen ChemistryGreen Manufacturing and EngineeringRisk assessment Regulatory Frameworks and Life-Cycle AssessmentsTreatment and Resource Recovery and Waste Management