Soil-gas data for the underground hydrocarbon contamination site in the Highland Avenue area, Fayetteville, Arkansas

1992 ◽  
Author(s):  
Gary L. Ford ◽  
J.V. Brahana
Keyword(s):  
Soil Gas ◽  
Hydrocarbon Contamination

An Evaluation of Soil-Gas Surveying for H2S for Locating Subsurface Hydrocarbon Contamination

1995 ◽  
Vol 15 (1) ◽  
pp. 124-132 ◽  
Author(s):  
Gary A. Robbins ◽  
Brian E. McAninch ◽  
Francis M. Gavas ◽  
Patricia M. Ellis
Keyword(s):  
Soil Gas ◽  
Hydrocarbon Contamination

Corrections for surface films in microanalysis by EDS and EELS

1992 ◽  
Vol 50 (2) ◽  
pp. 1230-1231
Author(s):  
J. Bentley ◽  
E. A. Kenik
Keyword(s):  
Hydrocarbon Contamination ◽  
Specimen Preparation ◽  
Surface Films ◽  
Ion Milling ◽  
Preferential Sputtering ◽  
Electron Energy Loss Spectrometry ◽  
Composition Determination ◽  
Analytical Electron ◽  
First Order Correction ◽  
Electron Energy Loss

Common artifacts on analytical electron microscope (AEM) specimens prepared from bulk materials are surface films with altered structure and composition that result from electropolishing, oxidation, hydrocarbon contamination, or ion milling (preferential sputtering or deposition of sputtered specimen or support material). Of course, the best solution for surface films is to avoid them by improved specimen preparation and handling procedures or to remove them by low energy ion sputter cleaning, a capability that already exists on some specialized AEMs and one that is likely to become increasingly common. However, the problem remains and it is surprising that surface films have not received more attention with respect to composition determination by energy dispersive X-ray spectrometry (EDS) and electron energy loss spectrometry (EELS).For EDS, an effective first-order correction to remove the contribution of surface films on wedge shaped specimens is to subtract from the spectrum of interest a spectrum obtained under identical conditions (probe current, diffracting conditions, acquisition live time) from a thinner region of the specimen.

Soil gas emission measurements in long term tillage experiments

2005 ◽  
Vol 33 (1) ◽  
pp. 373-376 ◽  
Author(s):  
Péter Hegymegi ◽  
Anita Gál ◽  
Imre Czinkota ◽  
Tony Vyn
Keyword(s):  
Soil Gas ◽  
Gas Emission

Choosing an appropriate soil-gas survey method

1992 ◽  
Vol 21 (1) ◽  
pp. 27-35 ◽  
Author(s):  
Nic Korte ◽  
Sandra Wagner ◽  
Jon Nyquist
Keyword(s):  
Soil Gas ◽  
Survey Method ◽  
Soil Gas Survey

scholarly journals Irrigation Scheduling with Soil Gas Diffusivity as a Decision Tool to Mitigate N2O Emissions from a Urine-Affected Pasture

Agriculture ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 443
Author(s):  
Camille Rousset ◽  
Timothy J. Clough ◽  
Peter R. Grace ◽  
David W. Rowlings ◽  
Clemens Scheer
Keyword(s):  
Irrigation Management ◽  
Irrigation Treatment ◽  
Irrigation Scheduling ◽  
Soil Gas ◽  
N2o Emissions ◽  
Irrigation Frequency ◽  
Water Demands ◽  
Gas Diffusivity ◽  
Matter Production ◽  
Access To Water

Pastures require year-round access to water and in some locations rely on irrigation during dry periods. Currently, there is a dearth of knowledge about the potential for using irrigation to mitigate N2O emissions. This study aimed to mitigate N2O losses from intensely managed pastures by adjusting irrigation frequency using soil gas diffusivity (Dp/Do) thresholds. Two irrigation regimes were compared; a standard irrigation treatment based on farmer practice (15 mm applied every 3 days) versus an optimised irrigation treatment where irrigation was applied when soil Dp/Do was ≈0.033 (equivalent to 50% of plant available water). Cow urine was applied at a rate of 700 kg N ha−1 to simulate a ruminant urine deposition event. In addition to N2O fluxes, soil moisture content was monitored hourly, Dp/Do was modelled, and pasture dry matter production was measured. Standard irrigation practices resulted in higher (p = 0.09) cumulative N2O emissions than the optimised irrigation treatment. Pasture growth rates under treatments did not differ. Denitrification during re-wetting events (irrigation and rain) contributed to soil N2O emissions. These results warrant further modelling of irrigation management as a mitigation option for N2O emissions from pasture soils, based on Dp/Do thresholds, rainfall, plant water demands and evapotranspiration.

scholarly journals Box Experiment Study of Thermally Enhanced SVE for Benzene

2021 ◽  
Vol 18 (8) ◽  
pp. 4062
Author(s):  
Qixiang Zhang ◽  
Qiyan Feng ◽  
Xueqiang Zhu ◽  
Mei Zhang ◽  
Yanjun Wang ◽  
...  
Keyword(s):  
Temperature Distribution ◽  
Concentration Distribution ◽  
Average Concentration ◽  
Soil Gas ◽  
Vapor Extraction ◽  
Operation Process ◽  
Repair Efficiency ◽  
Benzene Concentration ◽  
Benzene Content ◽  
Peak Value

In order to describe the changes of soil temperature field, air flow field and remediation situation with time during the process of thermally enhanced SVE (soil vapor extraction), a remediation experiment of benzene contaminated soil with single extraction pipe was carried out in a box device. The results showed that the whole temperature of the system was raised to 80 °C in 4 h. 43% of benzene were removed in the first 2% of the extraction time. After 24 h, the repair efficiency was close to 100%. The device can efficiently remove benzene from soil. By continuously monitoring the parameters in the operation process of the system, the spatial distribution of temperature and soil gas pollutant concentration with time was plotted. It showed the benzene concentration distribution in the soil gas was more consistent with the temperature distribution before the start of ventilation, and the concentration of benzene in the soil gas dropped rapidly after ventilation, while the temperature distribution was almost unaffected. In the treatment of soil with a benzene content of 17.8 mg∙kg−1, when the soil gas benzene concentration is the highest at 180 min, the peak value is 11,200 mg∙m−3, and the average concentration is 7629.4 mg∙m−3.

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