790 results

Comparison between PVI2D and Abreu–Johnson's Model for Petroleum Vapor Intrusion Assessment

Yijun Yao; Yue Wang; Iason Verginelli et al.

Vadose Zone Journal, Vol. 15 No. 11 · 2016 · English · DOAJ Scopus

Core Ideas A full comparison between PVI2D and the AJM for PVI assessment is provided. PVI2D returns results similar to AJM but with much less computational effort. PVI2D can be used as a 2D PVI tool for cases involving homogenous soil and source. Recently, we have developed a two‐dimensional…

Time‐Lapse Electrical Imaging of Water Infiltration in the Context of Soil Aquifer Treatment

Klaus Haaken; Alex Furman; Noam Weisbrod et al.

Vadose Zone Journal, Vol. 15 No. 11 · 2016 · English · DOAJ Scopus

Core Ideas We investigated geoelectrical monitoring of water infiltration within soil aquifer treatment. Time‐lapse ERT is able to track water infiltration under very high recurrent fluxes. Individual apparent resistivity captures temporal dynamics of water infiltration. Spatiotemporal ERT…

Accuracy of Lysimeters for Dissolved Copper, Antimony, Lead, and Zinc Sampling under Small Arms Backstop

Richard Martel; Pascal Castellazzi; Luc Trépanier et al.

Vadose Zone Journal, Vol. 13 No. 8 · 2014 · English · DOAJ Scopus

Three assays were conducted to evaluate the reliability of lysimeters in detecting concentrations of Cu, Pb, Sb, and Zn in interstitial water of the vadose zone. Two box lysimeters (BLs) made from polyvinyl chloride (PVC) and polyvinylidene fluoride (PVDF) and three tension lysimeters (TLs) of…

Distribution of Phosphorus‐Containing Fine Colloids and Nanoparticles in Stream Water of a Forest Catchment

Nina Gottselig; Roland Bol; Volker Nischwitz et al.

Vadose Zone Journal, Vol. 13 No. 7 · 2014 · English · DOAJ Scopus

Natural fine colloids and nanoparticles have the potential to encapsulate and bind nutrients. Their size and composition is therefore relevant to understand the transport of essential nutrients like phosphorus in an aquatic ecosystem. The aim of this study was to characterize fine colloidal and…

Biogeochemical Interface Formation: Wettability Affected by Organic Matter Sorption and Microbial Activity

Axel Lamparter; Joerg Bachmann; Susanne K Woche et al.

Vadose Zone Journal, Vol. 13 No. 7 · 2014 · English · DOAJ Scopus

Batch incubation and column percolation experiments with dissolved organic matter solution at different pH values were performed to investigate the effect of organic matter sorption and microbial activity on the wettability of clean quartz sand particles. Sodium azide was used as a biocide to…

Response of Dissolved Organic Matter in the Forest Floor of a Temperate Spruce Stand to Increasing Throughfall

Thimo Klotzbücher; Klaus Kaiser; Karsten Kalbitz

Vadose Zone Journal, Vol. 13 No. 7 · 2014 · English · DOAJ Scopus

In temperate spruce forests, dissolved organic matter (DOM) from forest floors is the major source of organic matter entering the mineral soil and thus it determines important soil properties and element cycling through the ecosystem. We examined effects of doubling locally collected throughfall…

Interactions of Soluble and Solid Organic Amendments with Priming Effects Induced by Glucose

Ramya Thangarajan; Saikat Chowdhury; Anitha Kunhikrishnan et al.

Vadose Zone Journal, Vol. 13 No. 7 · 2014 · English · DOAJ Scopus

In this work, the effects of various dissolved organic matter (DOM) sources (piggery effluent [PigE], dairy effluent [DE], sewage effluent [SE], and stormwater [SW]) on the priming effect (PE) of soil C as affected by solid organic amendments (biochar [BC], biosolids [BS], compost, and poultry…

Factors Controlling the Dissolved Organic Matter Concentration in Pore Waters of Agricultural Soils

Inne De Troyer; Roel Merckx; Fien Amery et al.

Vadose Zone Journal, Vol. 13 No. 7 · 2014 · English · DOAJ Scopus

Dissolved organic matter (DOM) affects a wide range of soil processes, but it is generally unknown which factors control its concentration. Here we report a survey of soil solution dissolved organic carbon (DOC) concentrations in agricultural soils with contrasting properties. Eighty‐seven…

Constraints on the Sources and Production Mechanisms of Dissolved Organic Matter in Soils from Molecular Biomarkers

L. Jeanneau; A. Jaffrezic; A.-C. Pierson-Wickmann et al.

Vadose Zone Journal, Vol. 13 No. 7 · 2014 · English · DOAJ Scopus

Spatio‐temporal modifications of the composition of dissolved organic matter (DOM) from a wetland in an agricultural catchment were investigated using thermally assisted hydrolysis and methylation with tetramethylammonium hydroxide coupled to gas chromatography and mass spectrometry (THM‐GC–MS)…

Pore‐Water Extraction from Unsaturated Porous Media: Intermediate‐Scale Laboratory Experiments and Simulations

M. Oostrom; M.J. Truex; T.W. Wietsma et al.

Vadose Zone Journal, Vol. 13 No. 8 · 2014 · English · DOAJ Scopus

As a remedial approach, vacuum‐induced pore‐water extraction offers the possibility of contaminant and water removal from the vadose zone, which may be beneficial in reducing the flux of vadose zone contaminants to groundwater. Vadose zone water extraction is being considered at the Hanford Site in…

In Situ Visualization and Quantification of Three‐Dimensional Root System Architecture and Growth Using X‐Ray Computed Tomography

Nicolai Koebernick; Ulrich Weller; Katrin Huber et al.

Vadose Zone Journal, Vol. 13 No. 8 · 2014 · English · DOAJ Scopus

Root system architecture and associated root–soil interactions exhibit large changes over time. Nondestructive methods for the quantification of root systems and their temporal development are needed to improve our understanding of root activity in natural soils. X‐ray computed tomography (X‐ray…

Using Classification Trees to Evaluate the Performance of Pedotransfer Functions

R.S. Boschi; L.H.A. Rodrigues; M.L.R.C. Lopes-Assad

Vadose Zone Journal, Vol. 13 No. 8 · 2014 · English · DOAJ Scopus

One issue in understanding the performance of pedotransfer functions (PTFs) is knowing the soil properties that contribute most to PTF errors. Classification trees provide a means for identifying these properties. The objective of this study was to use a classification tree to identify patterns in…

Woody Vegetation Increases Saturated Hydraulic Conductivity in Dry Tropical Nicaragua

R.J. Niemeyer; A.K. Fremier; R. Heinse et al.

Vadose Zone Journal, Vol. 13 No. 1 · 2014 · English · DOAJ Scopus

Land conversion in the tropics from primary forest to agricultural land has altered soil hydrologic processes. Woody vegetation is known to increase infiltration rates and saturated hydraulic conductivity (KS) in primary forests compared with agricultural land, but it is less clear if this…

The Cold Vadose Zone: Hydrological and Ecological Significance of Frozen‐Soil Processes

Masaki Hayashi

Vadose Zone Journal, Vol. 13 No. 1 · 2014 · English · DOAJ Scopus

Physicochemical Factors Influencing the Preferential Transport of Escherichia coli in Soils

Yusong Wang; Scott A. Bradford; Jiří Šimůnek

Vadose Zone Journal, Vol. 13 No. 1 · 2014 · English · DOAJ Scopus

Laboratory and numerical studies were conducted to investigate the transport and release of Escherichia coli D21g in preferential flow systems with artificial macropores under different ionic strength (IS) conditions. Macropores were created by embedding coarse sand lenses in a fine sand matrix and…

Soil Bulk Density and Moisture Content Influence Relative Gas Diffusivity and the Reduction of Nitrogen‐15 Nitrous Oxide

Roland R. Klefoth; Tim J. Clough; Oene Oenema et al.

Vadose Zone Journal, Vol. 13 No. 11 · 2014 · English · DOAJ Scopus

Nitrous oxide is a greenhouse gas and contributes to stratospheric ozone depletion. Soil physical conditions may influence N2O reduction and subsequent N2O emissions. We studied how soil water‐filled pore space (WFPS) and soil bulk density (ρb) affect N2O reduction and surface fluxes. Columns were…

Theoretical Relationship between Saturated Hydraulic Conductivity and Air Permeability under Dry Conditions: Continuum Percolation Theory

Behzad Ghanbarian; Allen G. Hunt; Robert P. Ewing et al.

Vadose Zone Journal, Vol. 13 No. 8 · 2014 · English · DOAJ Scopus

The saturated hydraulic conductivity, Ks, is a fundamental characteristic of subsurface flow and the hydrologic cycle. However, direct measurement of Ks is time consuming. Recently, air permeability measurements at 50 and 100 cm of H2O tension, a relatively dry condition in coarse and…

Relationship between Anisotropy in Soil Hydraulic Conductivity and Saturation

Z. Fred Zhang

Vadose Zone Journal, Vol. 13 No. 6 · 2014 · English · DOAJ Scopus

Anisotropy in unsaturated hydraulic conductivity is saturation‐dependent. Accurate characterization of soil anisotropy is very important in simulating flow and contaminant transport (e.g., radioactive nuclides at the U.S. Department of Energy's Hanford Site). A tensorial connectivity–tortuosity…

Properties of Dissolved Organic Matter in Peatland: Implications for Water Quality after Harvest

Oili Kiikkilä; Aino Smolander; Liisa Ukonmaanaho

Vadose Zone Journal, Vol. 13 No. 7 · 2014 · English · DOAJ Scopus

We studied the properties of dissolved organic matter (DOM) in drained boreal peatland in stem‐only‐harvested (SOH), whole‐tree‐harvested (WTH), and unharvested sites. The DOM derived from both aerobic and anaerobic peat layers was divided into four different molecular‐weight fractions with…

Reproducing Field‐Scale Active Layer Thaw in the Laboratory

Aaron A. Mohammed; Robert A. Schincariol; Ranjeet M. Nagare et al.

Vadose Zone Journal, Vol. 13 No. 8 · 2014 · English · DOAJ Scopus

A method to simulate freeze–thaw and permafrost conditions on a large peat‐soil column, housed in a biome, was developed. The design limits ambient temperature interference and maintains one‐dimensional freezing and thawing. An air circulation system, in a cavity surrounding the active layer…