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EXECUTIVE SUMMARIES

This Issue in Journal of Environmental Quality

	Timing is Everything!

TOP Timing is Everything! Permeability and Pore Size... Submergence Decreases... Soil-Water Studied by Stray... Paramagnetic Effects on Carbon... Improvements in the 2-D... NMR Imaging in Porous... Bioremediation of TNT... Condensed Tannins Linked to... MRI of Fluid Flow... Inositol Phosphate Measurement... Mobile Phosphorus Determination... Design Determines Detention Pond... Heteroaromatic-N After Prolonged... Transport Imaging in Porous... Do Harvesting and Climate... High-Resolution Measurement of... Industrial Impact on Marsh... Management Techniques to Reduce... Lead Bioavailability and Metal... River Phosphorus Concentrations... Environmentally Friendly Fate of... N Fixation, CO2, and... Necrosis Related to Tissue... Shallow Soils Buffer Rain... Polyacrylamide Removes Itself... Dissolution Kinetics of Heavy... Wildfire Intensifies Wind... Heavy Metal Sorption in... Microcosm Wetlands for... Light Intensity Interacts with... Little Leaching of Biosolids... Arsenic Hyperaccumulation by...

B. Cade-Menun

(bjcm{at}pangea.stanford.edu)

Soil and Litter Phosphorus-31 Nuclear Magnetic Resonance Spectroscopy: Extractants, Metals, and Phosphorus Relaxation Times. J. Environ. Qual. 31:457–465.

	Permeability and Pore Size Distribution of Porous Media

TOP Timing is Everything! Permeability and Pore Size... Submergence Decreases... Soil-Water Studied by Stray... Paramagnetic Effects on Carbon... Improvements in the 2-D... NMR Imaging in Porous... Bioremediation of TNT... Condensed Tannins Linked to... MRI of Fluid Flow... Inositol Phosphate Measurement... Mobile Phosphorus Determination... Design Determines Detention Pond... Heteroaromatic-N After Prolonged... Transport Imaging in Porous... Do Harvesting and Climate... High-Resolution Measurement of... Industrial Impact on Marsh... Management Techniques to Reduce... Lead Bioavailability and Metal... River Phosphorus Concentrations... Environmentally Friendly Fate of... N Fixation, CO2, and... Necrosis Related to Tissue... Shallow Soils Buffer Rain... Polyacrylamide Removes Itself... Dissolution Kinetics of Heavy... Wildfire Intensifies Wind... Heavy Metal Sorption in... Microcosm Wetlands for... Light Intensity Interacts with... Little Leaching of Biosolids... Arsenic Hyperaccumulation by...

 
Porosity and permeability of porous and fractured geological media decrease during exploitation of formation fluids such as petroleum, natural gas, or ground water due to the decrease in fluid pressure. This may result in ground subsidence and damage to petroleum, natural gas, or ground water wells. Therefore, an evaluation of the behavior of permeability and porosity under formation fluid pressure changes is important to petroleum and ground water industries. This study establishes a method that allows simultaneous measurement of permeability, porosity, and pore size distribution of cores. While permeability is determined in a classical Darcy setup, pore size distribution is obtained by low-field standard NMR relaxation time spectrometry, and porosity is determined with standard NMRI. The experiments allow derivation of the mechanisms responsible for pressure-dependent porosity and permeability changes.

W. Kinzelbach

(kinzelbach{at}ihw.baug.ethz.ch)

Variations of Permeability and Pore Size Distribution of Porous Media with Pressure. J. Environ. Qual. 31: 500–505.

	Submergence Decreases Humification in Lowland Rice

TOP Timing is Everything! Permeability and Pore Size... Submergence Decreases... Soil-Water Studied by Stray... Paramagnetic Effects on Carbon... Improvements in the 2-D... NMR Imaging in Porous... Bioremediation of TNT... Condensed Tannins Linked to... MRI of Fluid Flow... Inositol Phosphate Measurement... Mobile Phosphorus Determination... Design Determines Detention Pond... Heteroaromatic-N After Prolonged... Transport Imaging in Porous... Do Harvesting and Climate... High-Resolution Measurement of... Industrial Impact on Marsh... Management Techniques to Reduce... Lead Bioavailability and Metal... River Phosphorus Concentrations... Environmentally Friendly Fate of... N Fixation, CO2, and... Necrosis Related to Tissue... Shallow Soils Buffer Rain... Polyacrylamide Removes Itself... Dissolution Kinetics of Heavy... Wildfire Intensifies Wind... Heavy Metal Sorption in... Microcosm Wetlands for... Light Intensity Interacts with... Little Leaching of Biosolids... Arsenic Hyperaccumulation by...

 
To determine the effects of intensive cropping of tropical lowland rice and the associated soil submergence on chemical properties of soil organic matter, we used solid-state ¹³C and ¹⁵N and solution ³¹P nuclear magnetic resonance spectroscopy to analyze the labile mobile humic acid and the more recalcitrant Ca humate fractions extracted from a series of soils supporting several long-term field experiments in the Philippines. All analyses associated an increasing intensity of rice cropping with larger proportions of less humified material in both fractions, such as diester P, amide N, and phenolic C. We established significant correlations between proportions of various spectral areas as well as between some spectral areas and other humic acid properties such as visible light absorption and free radical concentration (positive indices of humification) and H concentration (negative index of humification).

N. Mahieu (n.mahieu{at}qmul.ac.uk)

Multinuclear Magnetic Resonance Analysis of Two Humic Acid Fractions from Lowland Rice Soils. J. Environ. Qual. 31: 421–430.

	Soil–Water Studied by Stray-Field NMR

TOP Timing is Everything! Permeability and Pore Size... Submergence Decreases... Soil-Water Studied by Stray... Paramagnetic Effects on Carbon... Improvements in the 2-D... NMR Imaging in Porous... Bioremediation of TNT... Condensed Tannins Linked to... MRI of Fluid Flow... Inositol Phosphate Measurement... Mobile Phosphorus Determination... Design Determines Detention Pond... Heteroaromatic-N After Prolonged... Transport Imaging in Porous... Do Harvesting and Climate... High-Resolution Measurement of... Industrial Impact on Marsh... Management Techniques to Reduce... Lead Bioavailability and Metal... River Phosphorus Concentrations... Environmentally Friendly Fate of... N Fixation, CO2, and... Necrosis Related to Tissue... Shallow Soils Buffer Rain... Polyacrylamide Removes Itself... Dissolution Kinetics of Heavy... Wildfire Intensifies Wind... Heavy Metal Sorption in... Microcosm Wetlands for... Light Intensity Interacts with... Little Leaching of Biosolids... Arsenic Hyperaccumulation by...

 
Soil samples consist of solid, liquid, and gaseous phases. A device to study undisturbed samples in which the matric potential of water can be varied will aid interpretation of water retention curves. Kinchesh et al. describe the construction and characterization of a unique device to study 5-cm-diameter soil cores by NMR in the strong stray field gradient of a superconducting magnet. Measurements of relative pore-size distribution in a 100-micron-thick slice are demonstrated and the effect of varying the matric potential on the filled pore distribution are presented. Some large-diameter pores remain filled even when the soil is partially drained, which confirms the hypothesis that the parallel-sided capillary tube model is insufficient to describe a soil containing pores interconnected by narrow necks.

A.R. Preston

(a.r.preston{at}qmul.ac.uk)

Stray Field Nuclear Magnetic Resonance of Soil Water: Development of a New, Large Probe and Preliminary Results. J. Environ. Qual. 31: 494–499.

	Paramagnetic Effects on Carbon-13 NMR Spectra

TOP Timing is Everything! Permeability and Pore Size... Submergence Decreases... Soil-Water Studied by Stray... Paramagnetic Effects on Carbon... Improvements in the 2-D... NMR Imaging in Porous... Bioremediation of TNT... Condensed Tannins Linked to... MRI of Fluid Flow... Inositol Phosphate Measurement... Mobile Phosphorus Determination... Design Determines Detention Pond... Heteroaromatic-N After Prolonged... Transport Imaging in Porous... Do Harvesting and Climate... High-Resolution Measurement of... Industrial Impact on Marsh... Management Techniques to Reduce... Lead Bioavailability and Metal... River Phosphorus Concentrations... Environmentally Friendly Fate of... N Fixation, CO2, and... Necrosis Related to Tissue... Shallow Soils Buffer Rain... Polyacrylamide Removes Itself... Dissolution Kinetics of Heavy... Wildfire Intensifies Wind... Heavy Metal Sorption in... Microcosm Wetlands for... Light Intensity Interacts with... Little Leaching of Biosolids... Arsenic Hyperaccumulation by...

 
Paramagnetic species—such as Fe oxides and Fe, Cu, and Mn cations—have long been known to cause problems in obtaining ¹³C NMR spectra of soil organic matter. Smernik and Oades now quantify this interference in terms of decreases in ¹³C NMR observability for model systems and isolated soil organic matter, doped with a range of paramagnetic species. Signal loss is shown to depend on the nature of the species and intimacy of mixing, as well as the concentration of the paramagnetic species. Three mechanisms for signal loss are identified for CPMAS spectra. Signal loss and increases in relaxation rates caused by paramagnetic doping are put to good use in identifying the nature of cation exchange sites on soil organic matter and in probing its submicron structure.

R. Smernik

(ronald.smernik{at}adelaide.edu.au)

Paramagnetic Effects on Solid State Carbon-13 Nuclear Magnetic Resonance Spectra of Soil Organic Matter. J. Environ. Qual. 31: 414–420.

	Improvements in the 2-D NMR of Humic Substances

TOP Timing is Everything! Permeability and Pore Size... Submergence Decreases... Soil-Water Studied by Stray... Paramagnetic Effects on Carbon... Improvements in the 2-D... NMR Imaging in Porous... Bioremediation of TNT... Condensed Tannins Linked to... MRI of Fluid Flow... Inositol Phosphate Measurement... Mobile Phosphorus Determination... Design Determines Detention Pond... Heteroaromatic-N After Prolonged... Transport Imaging in Porous... Do Harvesting and Climate... High-Resolution Measurement of... Industrial Impact on Marsh... Management Techniques to Reduce... Lead Bioavailability and Metal... River Phosphorus Concentrations... Environmentally Friendly Fate of... N Fixation, CO2, and... Necrosis Related to Tissue... Shallow Soils Buffer Rain... Polyacrylamide Removes Itself... Dissolution Kinetics of Heavy... Wildfire Intensifies Wind... Heavy Metal Sorption in... Microcosm Wetlands for... Light Intensity Interacts with... Little Leaching of Biosolids... Arsenic Hyperaccumulation by...

 
Nuclear magnetic resonance spectroscopy has long been a tool in organic chemistry and biochemistry. Recently, this powerful technique has been used successfully to study humic substances from soils and sediments. Two-dimensional NMR experiments can provide much more detail than that obtained from 1-D; however, the multitude of experiments available can make its application complicated. This paper presents data that demonstrate some 2-D experiments are better suited for humic substances than others. This information will assist the future application of 2-D NMR to humic substances.

A.J. Simpson

(asimpson{at}chemistry.ohio-state.edu)

Improvements in the Two-Dimensional Nuclear Magnetic Resonance Spectroscopy of Humic Substances. J. Environ. Qual. 31: 388–392.

	NMR Imaging in Porous Media

TOP Timing is Everything! Permeability and Pore Size... Submergence Decreases... Soil-Water Studied by Stray... Paramagnetic Effects on Carbon... Improvements in the 2-D... NMR Imaging in Porous... Bioremediation of TNT... Condensed Tannins Linked to... MRI of Fluid Flow... Inositol Phosphate Measurement... Mobile Phosphorus Determination... Design Determines Detention Pond... Heteroaromatic-N After Prolonged... Transport Imaging in Porous... Do Harvesting and Climate... High-Resolution Measurement of... Industrial Impact on Marsh... Management Techniques to Reduce... Lead Bioavailability and Metal... River Phosphorus Concentrations... Environmentally Friendly Fate of... N Fixation, CO2, and... Necrosis Related to Tissue... Shallow Soils Buffer Rain... Polyacrylamide Removes Itself... Dissolution Kinetics of Heavy... Wildfire Intensifies Wind... Heavy Metal Sorption in... Microcosm Wetlands for... Light Intensity Interacts with... Little Leaching of Biosolids... Arsenic Hyperaccumulation by...

 
Nuclear magnetic resonance imaging (NMRI) methods can be used in various ways for visualization of fluid flow and transport in porous media. The review shows examples for the application of two different principles: direct velocity imaging and the imaging of NMR tracer front movement in single phase, multiphase, and density flows. They illustrate the capacity of NMRI to give structural information both of the medium and the fluid distributions, as well as their temporal development. The resulting data can be used in a black box–white box comparison and as benchmarks for numerical models.

W. Kinzelbach

(kinzelbach{at}ihw.baug.ethz.ch)

Nuclear Magnetic Resonance Imaging for Studies of Flow and Transport in Porous Media. J. Environ. Qual. 31: 477–486.

	Bioremediation of TNT-Contaminated Sites

TOP Timing is Everything! Permeability and Pore Size... Submergence Decreases... Soil-Water Studied by Stray... Paramagnetic Effects on Carbon... Improvements in the 2-D... NMR Imaging in Porous... Bioremediation of TNT... Condensed Tannins Linked to... MRI of Fluid Flow... Inositol Phosphate Measurement... Mobile Phosphorus Determination... Design Determines Detention Pond... Heteroaromatic-N After Prolonged... Transport Imaging in Porous... Do Harvesting and Climate... High-Resolution Measurement of... Industrial Impact on Marsh... Management Techniques to Reduce... Lead Bioavailability and Metal... River Phosphorus Concentrations... Environmentally Friendly Fate of... N Fixation, CO2, and... Necrosis Related to Tissue... Shallow Soils Buffer Rain... Polyacrylamide Removes Itself... Dissolution Kinetics of Heavy... Wildfire Intensifies Wind... Heavy Metal Sorption in... Microcosm Wetlands for... Light Intensity Interacts with... Little Leaching of Biosolids... Arsenic Hyperaccumulation by...

 
Organic pollutants are degraded in the soil and simultaneously nonextractable residues are formed. Through their binding to soil, the transformed pollutants are no longer accessible to the biota; consequently, this process results in the bioremediation of contaminated sites. We investigated the transformation and binding of the explosive TNT (2,4,6-trinitrotoluene) using catechol, a humic monomer, or soil humic acid as cosubstrates. TNT was first reduced by anaerobic microorganisms and, after treatment with the fungal enzyme laccase, the resulting metabolites bound to humic material in the soil. This observation was confirmed using ¹⁵N–NMR spectra of ¹⁵N-labeled TNT and its ensuing metabolites.

Jean-Marc Bollag

(jmbollag{at}psu.edu)

Enzymatic Transformation and Binding of Labeled 2,4,6-Trinitrotoluene to Humic Substances during an Anaerobic/Aerobic Incubation. J. Environ. Qual. 31: 437–444.

	Condensed Tannins Linked to Nutrient Cycling?

TOP Timing is Everything! Permeability and Pore Size... Submergence Decreases... Soil-Water Studied by Stray... Paramagnetic Effects on Carbon... Improvements in the 2-D... NMR Imaging in Porous... Bioremediation of TNT... Condensed Tannins Linked to... MRI of Fluid Flow... Inositol Phosphate Measurement... Mobile Phosphorus Determination... Design Determines Detention Pond... Heteroaromatic-N After Prolonged... Transport Imaging in Porous... Do Harvesting and Climate... High-Resolution Measurement of... Industrial Impact on Marsh... Management Techniques to Reduce... Lead Bioavailability and Metal... River Phosphorus Concentrations... Environmentally Friendly Fate of... N Fixation, CO2, and... Necrosis Related to Tissue... Shallow Soils Buffer Rain... Polyacrylamide Removes Itself... Dissolution Kinetics of Heavy... Wildfire Intensifies Wind... Heavy Metal Sorption in... Microcosm Wetlands for... Light Intensity Interacts with... Little Leaching of Biosolids... Arsenic Hyperaccumulation by...

 
The fate of plant-derived condensed tannins in soils and their influence on nutrient cycling are hardly known. Lorenz and Preston show high-tannin fractions are extractable from a black spruce humus from a site in Northern Ontario, even if humus tannin levels are very low. Characterization of the extracts by ¹³C CPMAS NMR shows no evidence of tannin–protein complexes proposed as a mechanism for nitrogen sequestration. Further studies are needed to detect or isolate tannin–protein structures in humus and if condensed tannins contribute to forest management problems observed in black spruce ecosystems.

K. Lorenz

(lorenzk{at}uni-hohenheim.de)

Characterization of High-Tannin Fractions from Humus by Carbon-13 Cross- Polarization and Magic-Angle Spinning Nuclear Magnetic Resonance. J. Environ. Qual. 31: 431–436.

	MRI of Fluid Flow in Porous Media

TOP Timing is Everything! Permeability and Pore Size... Submergence Decreases... Soil-Water Studied by Stray... Paramagnetic Effects on Carbon... Improvements in the 2-D... NMR Imaging in Porous... Bioremediation of TNT... Condensed Tannins Linked to... MRI of Fluid Flow... Inositol Phosphate Measurement... Mobile Phosphorus Determination... Design Determines Detention Pond... Heteroaromatic-N After Prolonged... Transport Imaging in Porous... Do Harvesting and Climate... High-Resolution Measurement of... Industrial Impact on Marsh... Management Techniques to Reduce... Lead Bioavailability and Metal... River Phosphorus Concentrations... Environmentally Friendly Fate of... N Fixation, CO2, and... Necrosis Related to Tissue... Shallow Soils Buffer Rain... Polyacrylamide Removes Itself... Dissolution Kinetics of Heavy... Wildfire Intensifies Wind... Heavy Metal Sorption in... Microcosm Wetlands for... Light Intensity Interacts with... Little Leaching of Biosolids... Arsenic Hyperaccumulation by...

 
The movement of water in porous media, which makes up most of the shallow aquifers, is of prior importance for, e.g., an assessment of the risk of contamination of drinking water wells. Conventional laboratory techniques do not allow measurement of the flow velocity or the diffusion of water directly, thus leaving some uncertainty. This study demonstrates a method to measure these important parameters directly within the soil or sediment, while preserving the integrity of the sample. With magnetic resonance imaging (MRI), the propagation water in a sample can be visualized directly without adding any tracer chemicals. It is also possible to increase the spatial and temporal resolution of the experiment significantly. A better understanding of the processes involved in contaminant transport gained from MRI experiments contributes to an improvement in the prediction of the fate of contaminants in ground water.

T. Baumann

(thomas.baumann{at}ch.tum.de)

Flow and Diffusion Measurements in Natural Porous Media Using Magnetic Resonance Imaging. J. Environ. Qual. 31: 470–476.

	Inositol Phosphate Measurement Simplified

TOP Timing is Everything! Permeability and Pore Size... Submergence Decreases... Soil-Water Studied by Stray... Paramagnetic Effects on Carbon... Improvements in the 2-D... NMR Imaging in Porous... Bioremediation of TNT... Condensed Tannins Linked to... MRI of Fluid Flow... Inositol Phosphate Measurement... Mobile Phosphorus Determination... Design Determines Detention Pond... Heteroaromatic-N After Prolonged... Transport Imaging in Porous... Do Harvesting and Climate... High-Resolution Measurement of... Industrial Impact on Marsh... Management Techniques to Reduce... Lead Bioavailability and Metal... River Phosphorus Concentrations... Environmentally Friendly Fate of... N Fixation, CO2, and... Necrosis Related to Tissue... Shallow Soils Buffer Rain... Polyacrylamide Removes Itself... Dissolution Kinetics of Heavy... Wildfire Intensifies Wind... Heavy Metal Sorption in... Microcosm Wetlands for... Light Intensity Interacts with... Little Leaching of Biosolids... Arsenic Hyperaccumulation by...

 
Inositol phosphates are among the most important forms of P in nature, but are poorly understood because they are difficult to measure. We developed a method for measuring inositol hexakisphosphate, the most abundant type of inositol phosphate, in soil and water samples. The method involves the simultaneous separation and concentration of the compound onto a gel and detection by ³¹P nuclear magnetic resonance spectroscopy. With development, this method should help to reveal important information about these enigmatic P compounds.

B. Turner

(bturner{at}nwisrl.ars.usda.gov)

A Novel Technique for the Pre-Concentration and Extraction of Inositol Hexakisphosphate from Soil Extracts with Determination by Phosphorus-31 Nuclear Magnetic Resonance. J. Environ. Qual. 31: 466–470.

	Mobile Phosphorus Determination Using Solid-State NMR

TOP Timing is Everything! Permeability and Pore Size... Submergence Decreases... Soil-Water Studied by Stray... Paramagnetic Effects on Carbon... Improvements in the 2-D... NMR Imaging in Porous... Bioremediation of TNT... Condensed Tannins Linked to... MRI of Fluid Flow... Inositol Phosphate Measurement... Mobile Phosphorus Determination... Design Determines Detention Pond... Heteroaromatic-N After Prolonged... Transport Imaging in Porous... Do Harvesting and Climate... High-Resolution Measurement of... Industrial Impact on Marsh... Management Techniques to Reduce... Lead Bioavailability and Metal... River Phosphorus Concentrations... Environmentally Friendly Fate of... N Fixation, CO2, and... Necrosis Related to Tissue... Shallow Soils Buffer Rain... Polyacrylamide Removes Itself... Dissolution Kinetics of Heavy... Wildfire Intensifies Wind... Heavy Metal Sorption in... Microcosm Wetlands for... Light Intensity Interacts with... Little Leaching of Biosolids... Arsenic Hyperaccumulation by...

 
The solubility, form, and risk of P loss changes with soil P concentration. McDowell et al. used solid-state ³¹P NMR spectroscopy, high-power decoupling magic angle spinning NMR, and cross polarization NMR to determine potentially mobile P associated with Al and Ca in arable soils with Olsen P concentrations of 40 to 102 mg P kg^-1. Above a threshold of 59 mg Olsen P kg^-1, the potential for P loss increases. Comparison among soils indicated P above the threshold was present as a combination of soluble and loosely adsorbed (protonated–cross-polarized) P forms, largely associated with Ca as Monetite (CaHPO₄) and dicalcium phosphate dihydrate (CaHPO₄·2H₂O), and some Al associated P as Wavellite. These findings demonstrate solid-state NMR can provide good information on the chemical nature and risk of soil P species to water enrichment.

R. McDowell

(richard.mcdowell{at}agresearch.co.nz)

Analysis of Potentially Mobile Phosphorus in Arable Soils Using Solid State Nuclear Magnetic Resonance. J. Environ. Qual. 31: 450–456.

	Design Determines Detention Pond Performance

TOP Timing is Everything! Permeability and Pore Size... Submergence Decreases... Soil-Water Studied by Stray... Paramagnetic Effects on Carbon... Improvements in the 2-D... NMR Imaging in Porous... Bioremediation of TNT... Condensed Tannins Linked to... MRI of Fluid Flow... Inositol Phosphate Measurement... Mobile Phosphorus Determination... Design Determines Detention Pond... Heteroaromatic-N After Prolonged... Transport Imaging in Porous... Do Harvesting and Climate... High-Resolution Measurement of... Industrial Impact on Marsh... Management Techniques to Reduce... Lead Bioavailability and Metal... River Phosphorus Concentrations... Environmentally Friendly Fate of... N Fixation, CO2, and... Necrosis Related to Tissue... Shallow Soils Buffer Rain... Polyacrylamide Removes Itself... Dissolution Kinetics of Heavy... Wildfire Intensifies Wind... Heavy Metal Sorption in... Microcosm Wetlands for... Light Intensity Interacts with... Little Leaching of Biosolids... Arsenic Hyperaccumulation by...

 
Wet detention ponds are a common mitigation tool used to reduce inputs of nonpoint-source pollutants into natural water bodies. However, their efficacy at pollution reduction varies greatly among ponds. Mallin et al. conducted a 29-month study comparing inflow and outflow parameter concentrations of three regional wet detention ponds. The results demonstrated removal of nutrients, turbidity, and fecal coliform bacteria was high in ponds that combined large and diverse coverage of aquatic macrophytes with a high pond length/width ratio. Combining wet detention ponds with natural wetlands also aided in nutrient removal, whereas placing pond inputs near the outflow structure greatly reduced nutrient removal efficacy.

M.A. Mallin (mallinm{at}uncwil.edu)

Pollutant Removal Efficacy of Three Wet Detention Ponds. J. Environ. Qual. 31: 654–660.

	Heteroaromatic-N After Prolonged Humification

TOP Timing is Everything! Permeability and Pore Size... Submergence Decreases... Soil-Water Studied by Stray... Paramagnetic Effects on Carbon... Improvements in the 2-D... NMR Imaging in Porous... Bioremediation of TNT... Condensed Tannins Linked to... MRI of Fluid Flow... Inositol Phosphate Measurement... Mobile Phosphorus Determination... Design Determines Detention Pond... Heteroaromatic-N After Prolonged... Transport Imaging in Porous... Do Harvesting and Climate... High-Resolution Measurement of... Industrial Impact on Marsh... Management Techniques to Reduce... Lead Bioavailability and Metal... River Phosphorus Concentrations... Environmentally Friendly Fate of... N Fixation, CO2, and... Necrosis Related to Tissue... Shallow Soils Buffer Rain... Polyacrylamide Removes Itself... Dissolution Kinetics of Heavy... Wildfire Intensifies Wind... Heavy Metal Sorption in... Microcosm Wetlands for... Light Intensity Interacts with... Little Leaching of Biosolids... Arsenic Hyperaccumulation by...

 
Subjecting organic material from recent and fossilized sediments to solid-state ¹⁵N NMR spectroscopy, the transformation of organic N from plant debris was examined during peatification and coalification. While for recent material no indication of heteroaromatic N accumulation was found, spectra of the fossilized sample material was dominated by pyrrole-type N. As revealed from the deepest peat layer of a Holocene sapropel from Mangrove Lake, Bermuda, the transformation occurs between an advanced stage of peatification and an early stage of coalification, most probably due to abiotic processes.

H. Knicker

(knicker{at}weihenstephan.de)

Formation of Heteroaromatic Nitrogen after Prolonged Humification of Vascular Plant Remains as Revealed by Nuclear Magnetic Resonance Spectroscopy. J. Environ. Qual. 31: 444–449.

	Transport Imaging in Porous Media

TOP Timing is Everything! Permeability and Pore Size... Submergence Decreases... Soil-Water Studied by Stray... Paramagnetic Effects on Carbon... Improvements in the 2-D... NMR Imaging in Porous... Bioremediation of TNT... Condensed Tannins Linked to... MRI of Fluid Flow... Inositol Phosphate Measurement... Mobile Phosphorus Determination... Design Determines Detention Pond... Heteroaromatic-N After Prolonged... Transport Imaging in Porous... Do Harvesting and Climate... High-Resolution Measurement of... Industrial Impact on Marsh... Management Techniques to Reduce... Lead Bioavailability and Metal... River Phosphorus Concentrations... Environmentally Friendly Fate of... N Fixation, CO2, and... Necrosis Related to Tissue... Shallow Soils Buffer Rain... Polyacrylamide Removes Itself... Dissolution Kinetics of Heavy... Wildfire Intensifies Wind... Heavy Metal Sorption in... Microcosm Wetlands for... Light Intensity Interacts with... Little Leaching of Biosolids... Arsenic Hyperaccumulation by...

 
The detailed characterization of transport processes in porous media is of crucial importance to understand the fate of contaminants in soils. With development of the nuclear magnetic resonance imaging technique in recent years, a powerful instrument is available for detailed, high resolution, 3-D imaging of tracer concentrations in porous media. With this method, we have investigated the movement of Ni²⁺ in columns packed with glass beads and quartz sand. From the obtained 3-D movie, we have calculated the 3-D flow velocity field as well as the statistical properties, which serve either as the basis for novel 3-D computer models, or for their validation. Also, we have calculated the mean effective dispersion coefficient, which is established only after a minimum flow distance, depending on grain size.

K.-H. Herrmann

(k.-h.herrmann{at}fz-juelich.de)

Three-Dimensional Nickel Ion Transport through Porous Media Using Magnetic Resonance Imaging. J. Environ. Qual. 31: 506–514.

	Do Harvesting and Climate Affect Forest Soil Organic Matter?

TOP Timing is Everything! Permeability and Pore Size... Submergence Decreases... Soil-Water Studied by Stray... Paramagnetic Effects on Carbon... Improvements in the 2-D... NMR Imaging in Porous... Bioremediation of TNT... Condensed Tannins Linked to... MRI of Fluid Flow... Inositol Phosphate Measurement... Mobile Phosphorus Determination... Design Determines Detention Pond... Heteroaromatic-N After Prolonged... Transport Imaging in Porous... Do Harvesting and Climate... High-Resolution Measurement of... Industrial Impact on Marsh... Management Techniques to Reduce... Lead Bioavailability and Metal... River Phosphorus Concentrations... Environmentally Friendly Fate of... N Fixation, CO2, and... Necrosis Related to Tissue... Shallow Soils Buffer Rain... Polyacrylamide Removes Itself... Dissolution Kinetics of Heavy... Wildfire Intensifies Wind... Heavy Metal Sorption in... Microcosm Wetlands for... Light Intensity Interacts with... Little Leaching of Biosolids... Arsenic Hyperaccumulation by...

 
Harvesting of old-growth coastal forest in British Columbia has raised concerns about sustainability and preservation of its unique characteristics. We characterized C pools in recently harvested to old-growth stands on the west coast of Vancouver Island and the drier, slightly warmer east coast. Neither climate nor harvesting affected C concentration of five poorly decomposed organic matter pools. Carbon quality (carbon-13 NMR) also showed little harvesting effect, but small-scale variation, mainly due to coarse woody debris (a defining feature of old-growth) vs. tannin-rich roots. Wood had a greater influence in the west, and charcoal in the drier east side. The large old-growth legacy has minimized the impact of one harvest on organic matter, but more intensive management will likely reduce wood and charcoal inputs and microsite variability, with potential impact on biodiversity.

C.M. Preston

(cpreston{at}pfc.forestry.ca)

Harvesting and Climate Effects on Organic Matter Characteristics in British Columbia Coastal Forests. J. Environ. Qual. 31: 402–413.

	High-Resolution Measurement of Trace Gases

TOP Timing is Everything! Permeability and Pore Size... Submergence Decreases... Soil-Water Studied by Stray... Paramagnetic Effects on Carbon... Improvements in the 2-D... NMR Imaging in Porous... Bioremediation of TNT... Condensed Tannins Linked to... MRI of Fluid Flow... Inositol Phosphate Measurement... Mobile Phosphorus Determination... Design Determines Detention Pond... Heteroaromatic-N After Prolonged... Transport Imaging in Porous... Do Harvesting and Climate... High-Resolution Measurement of... Industrial Impact on Marsh... Management Techniques to Reduce... Lead Bioavailability and Metal... River Phosphorus Concentrations... Environmentally Friendly Fate of... N Fixation, CO2, and... Necrosis Related to Tissue... Shallow Soils Buffer Rain... Polyacrylamide Removes Itself... Dissolution Kinetics of Heavy... Wildfire Intensifies Wind... Heavy Metal Sorption in... Microcosm Wetlands for... Light Intensity Interacts with... Little Leaching of Biosolids... Arsenic Hyperaccumulation by...

 
A new technique is presented for the rapid, high-resolution identification and quantification of multiple trace gases above soils, at concentrations down to 10 ppb. The technique, selected ion flow tube mass spectrometry (SIFT-MS), uses selected chemical ionization methods to identify and quantify trace gases. The method is demonstrated by measuring emissions of NO, NH₃, and organics from soils treated with synthetic cattle urine, and shows that of the applied N, 7% is emitted as NH₃–N, 10% as NO–N, and none as N organics. The SIFT method allows simultaneous in situ measurement of multiple gas components with high spatial resolution of <10 cm and time resolution of <20 seconds, allowing the identification of emission hot-spots, measuring localized and rapid variations above agricultural and contaminated soils, and integrated emissions over longer periods.

M.N. Mautner

(mautnerm{at}lincoln.ac.nz)

Real-Time, High-Resolution Quantitative Measurement of Multiple Soil Gas Emissions: Selected Ion Flow Tube Mass Spectrometry. J. Environ. Qual. 31: 515–524.

	Industrial Impact on Marsh Soils

TOP Timing is Everything! Permeability and Pore Size... Submergence Decreases... Soil-Water Studied by Stray... Paramagnetic Effects on Carbon... Improvements in the 2-D... NMR Imaging in Porous... Bioremediation of TNT... Condensed Tannins Linked to... MRI of Fluid Flow... Inositol Phosphate Measurement... Mobile Phosphorus Determination... Design Determines Detention Pond... Heteroaromatic-N After Prolonged... Transport Imaging in Porous... Do Harvesting and Climate... High-Resolution Measurement of... Industrial Impact on Marsh... Management Techniques to Reduce... Lead Bioavailability and Metal... River Phosphorus Concentrations... Environmentally Friendly Fate of... N Fixation, CO2, and... Necrosis Related to Tissue... Shallow Soils Buffer Rain... Polyacrylamide Removes Itself... Dissolution Kinetics of Heavy... Wildfire Intensifies Wind... Heavy Metal Sorption in... Microcosm Wetlands for... Light Intensity Interacts with... Little Leaching of Biosolids... Arsenic Hyperaccumulation by...

 
The Bahia Blanca Estuary in Argentina