973 resultados para volatile halogenated organic compounds
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The purpose of this fact sheet is to provide a summary of literature research on the use of well "shooting" or blasting technology in Northern Illinois. Water well shooting or blasting is done to increase water yield from a sandstone aquifer for a particular water supply well ... The Lake County Health Department (LCHD) detected a chemical, vinyl chloride -- from a family of chemicals known as volatile organic compounds (VOCs) -- in some private wells in the unincorporated Hillcrest Subdivision near Wauconda, through routine well testing done in the fall of 2003. The LCHD presented these findings to the public at a January 13, 2004 meeting. The concern was raised at the public meeting that recent subsurface water well "shooting" or blasting techniques, performed in the deep sandstone aquifer (800 to 1,000 feet below ground surface), in the borehole of a community water supply (CWS) well in the area, might have impacted the shallow aquifer in such a way as to contribute to private well contamination under investigation in the Hillcrest Subdivision.
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"June 5, 2009"
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Updates on-site environmental investigations by the PREMCOR Refining Group at the former Clark-Blue Island Refinery which began operations as the Great Lakes Refinery in the mid 1920s and continued operating at the Blue Island (Ill.) site until PREMCOR closed the refinery in 2001. Valero Energy Corporation purchased PREMCOR on Sept. 1, 2005.
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"August 2010."
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Soil contamination on the Elm Street site is located mainly underneath and near the building foundation. Groundwater contamination appears to extend beyond the property boundaries to the west towards the Fox River, which is approximately 1100 feet west of the site. The groundwater contamination is located in a mixed industrial, commercial and residential area. It is not clear at this point whether there may be multiple sources of contamination in the area. Currently the public water supply is only available to some properties along Route 120, where there is a water main in place. Most of the homes and businesses in the area use private wells for their water source.
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Contamination in soil and groundwater was found during an investigation of a property located on the east side of the Fox River in McHenry, at 3004 W. Elm Street (Route 120) during 2003-2006. The property, currently owned by Inverse Investments, Inc., is enrolled in an Illinois Environmental Protection Agency (Illinois EPA) cleanup program. It is the location of a car rental establishment. Gem Cleaners occupied the site from 1970 to 1977, after which it was occupied by a carpet dealer, an automotive repair facility, and a tire store. Historic use of solvents at the former dry cleaner location has resulted in contamination of the soil and groundwater with chlorinated organic compounds.
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"HWRIC RR-074."
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"October 2011."
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"September 11, 2009"
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Errata slip inserted.
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Many studies have shown a reduction in P sorption in highly weathered soils when organic matter (OM) is applied, suggesting competition between OM decomposition products and P for sorption sites. However, such studies seldom consider the P released from the added OM. To delineate the effects of OM addition on P availability through sorption competition and P addition, water leachate from incubated soybean (SB) [Glycine mar (L.) Merr.] and Rhodes grass (RG) (Chloris gayana Knuth cv. Callide) was used in competitive P sorption studies both undiluted and after acidification (i.e., the fulvic acid [FA] component). Addition of two rates (0.2 and 2 mL) of SB leachate to an Oxisol significantly increased P sorption at the higher rate, while a similar trend was observed following RG leachate addition at the same rates. Extending the range of highly weathered soils examined (two Oxisols, an Ultisol, and an acidic Vertisol) resulted in no observed decrease in P sorption following addition of OM leachate. Surprisingly, SB leachate transiently increased P sorption in the two Oxisol soils. Addition of the FA component of the leachates resulted in a transient (< 6 d) decrease in P sorption in three of the four soils examined and constituted the only evidence in this study that decomposing OM residues reduced P sorption. This research provides further evidence contradicting the long held assumption that inhibition of P sorption by dissolved organic compounds, derived from decomposing OM, is responsible for increased P phytoavailability when P fertilizer and OM are applied together.
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This review covers the production and utilisation of liquids from the thermal processing of biomass and related materials to substitute for synthetic phenol and formaldehyde in phenol formaldehyde resins. These resins are primarily employed in the manufacture of wood panels such as plywood, MDF, particle-board and OSB. The most important thermal conversion methods for this purpose are fast pyrolysis and vacuum pyrolysis, pressure liquefaction and phenolysis. Many feedstocks have been tested for their suitability as sources of phenolics including hard and softwoods, bark and residual lignins. Resins have been prepared utilising either the whole liquid product, or a phenolics enriched fraction obtained after fractional condensation or further processing, such as solvent extraction. None of the phenolics production and fractionation techniques covered in this review are believed to allow substitution of 100% of the phenol content of the resin without impacting its effectiveness compared to commercial formulations based on petroleum derived phenol. This survey shows that considerable progress has been made towards reaching the goal of a price competitive renewable resin, but that further research is required to meet the twin challenges of low renewable resin cost and satisfactory quality requirements. Particular areas of concern are wood panel press times, variability of renewable resin properties, odour, lack of reactive sites compared to phenol and potential for increased emissions of volatile organic compounds.
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Many organic compounds cause an irreversible damage to human health and the ecosystem and are present in water resources. Among these hazard substances, phenolic compounds play an important role on the actual contamination. Utilization of membrane technology is increasing exponentially in drinking water production and waste water treatment. The removal of organic compounds by nanofiltration membranes is characterized not only by molecular sieving effects but also by membrane-solute interactions. Influence of the sieving parameters (molecular weight and molecular diameter) and the physicochemical interactions (dissociation constant and molecular hydrophobicity) on the membrane rejection of the organic solutes were studied. The molecular hydrophobicity is expressed as logarithm of octanol-water partition coefficient. This paper proposes a method used that can be used for symbolic knowledge extraction from a trained neural network, once they have been trained with the desired performance and is based on detect the more important variables in problems where exist multicolineality among the input variables.
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Highly sensitive and selective detection of volatile organic compounds (VOCs) with fast response time is imperative based on safety requirements, yet often remains a challenge. Herein, we propose an effective solution, preparing a novel gas sensor comprised of amorphous nanoflake arrays (a-NFAs) with specific surface groups. The sensor was produced via an extremely simple process in which a-NFAs of CdO were deposited directly onto an interdigital electrode immersed in a chemical bath under ambient conditions. Upon exposure to a widely used VOC, diethyl ether (DEE), the sensor exhibits excellent performance, more specifically, the quickest response, lowest detection limit and highest selectivity ever reported for DEE as a target gas. The superior gas-sensing properties of the prepared a-NFAs are found to arise from their open trumpet-shaped morphology, defect-rich amorphous nature, and surface CO groups.
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The Intoxilyzer 5000 was tested for calibration curve linearity for ethanol vapor concentration between 0.020 and 0.400g/210L with excellent linearity. Calibration error using reference solutions outside of the allowed concentration range, response to the same ethanol reference solution at different temperatures between 34 and 38$\sp\circ$C, and its response to eleven chemicals, 10 mixtures of two at the time, and one mixture of four chemicals potentially found in human breath have been evaluated. Potential interferents were chosen on the basis of their infrared signatures and the concentration range of solutions corresponding to the non-lethal blood concentration range of various volatile organic compounds reported in the literature. The result of this study indicates that the instrument calibrates with solutions outside the allowed range up to $\pm$10% of target value. Headspace FID dual column GC analysis was used to confirm the concentrations of the solutions. Increasing the temperature of the reference solution from 34 to 38$\sp\circ$C resulted in linear increases in instrument recorded ethanol readings with an average increase of 6.25%/$\sp\circ$C. Of the eleven chemicals studied during this experiment, six, isopropanol, toluene, methyl ethyl ketone, trichloroethylene, acetaldehyde, and methanol could reasonably interfere with the test at non-lethal reported blood concentration ranges, the mixtures of those six chemicals showed linear additive results with a combined effect of as much as a 0.080g/210L reading (Florida's legal limit) without any ethanol present. ^