acid gas sampling Articles | Environmental XPRT

Sampling VOCs with Supel™-Inert Film Gas Sampling Bags

Sampling VOCs with Supel™-Inert Film Gas Sampling Bags with Thermogreen™ LB-2 Septa as an Alternative to Tedlar® For 10 years, Supelco has provided our customers with high quality Tedlar gas sampling bags. Recently, we expanded our gas sampling bag line to include an alternative to Tedlar for sampling VOCs that incorporates our low-bleed Thermogreen™ LB-2 ...

Jun. 5, 2012

By MilliporeSigma

Sampling errors in the study of acid gases and anion species in atmospheric aerosols

Atmospheric acid aerosols were sampled by two annular denuder systems (ADS) and a micro-orifice uniform deposit impactor (MOUDI) at a traffic site in central Taiwan. Theoretical analysis showed that the relative artifact for HNO3 gas sampling was about 0.53 when the initial HNO3 concentration was under 0.2 µg/m³ and should be considered carefully. The ...

Sep. 6, 2004

By Inderscience Publishers

Monitoring of Hydrogen Sulfide in Industrial Processes

Hydrogen sulfide, H2S, is a very poisonous, corrosive, and flammable gas. As such, it needs to be carefully monitored and controlled in industrial processes where it is generated or used. At relatively low concentrations, it has an odour of rotten eggs which effectively works as a warning, but at higher concentrations where it becomes acutely toxic and even lethal, it can no longer be smelled ...

Oct. 14, 2018

By Opsis AB

Reducing NOx in Diesel Emissions | Spectroscopy Solutions

Air pollution and NOx emissions from diesel engines are a global concern due to their potential impacts on human health. Researchers worldwide are developing new and improved methods to reduce NOx emissions. Infrared spectroscopy in the gas phase, which is made possible using FTIR gas cells from Specac, has an important role to play in this ...

Feb. 7, 2018

By Specac Limited

An Easy Guide to Understanding Surfactants

What is a Surfactant? Surfactants are a primary component of cleaning detergents. The word surfactant means surface active agent. As the name implies, surfactants stir up activity on the surface you are cleaning to help trap dirt and remove it from the surface. Surfactants have a hydrophobic (water-hating) tail and a hydrophilic (water-loving) head. The hydrophobic tail of each ...

Jul. 30, 2018

By International Products Corporation

Simultaneous determination of trace lead and cadmium in water samples by adsorptive stripping voltammetry using gallic acid as a selective chelating agent

This work describes a procedure for the simultaneous determination of cadmium and lead in some food and water samples using an adsorptive stripping voltammetric method. The method is based on the adsorptive accumulation of 2,3,4-trihydroxybenzoic acid (gallic acid (GA)) complexes of these elements onto a hanging mercury drop electrode, followed by the reduction of the adsorbed species. Optimal ...

Jun. 7, 2015

By IWA Publishing

Biodegradation Tests for Wastewater Samples

Biodegradation Tests for Wastewater Samples Biodegradation tests usually involve comparison of the oxygen uptake of a test sample – or gas production for anoxic or anaerobic tests – to that for a readily biodegradable control substrate (usually acetic acid, ethanol, or aniline). While biodegradation characteristics can vary among chemical types and wastewater sources, typical patterns are shown ...

Dec. 31, 2002

By Challenge Technology

Understanding the atmospheric measurement and behavior of perfluorooctanoic acid

The recently reported quantification of the atmospheric sampling artifact for perfluorooctanoic acid (PFOA) was applied to existing gas and particle concentration measurements. Specifically, gas phase concentrations were increased by a factor of 3.5 and particle‐bound concentrations by a factor of 0.1. The correlation constants in two particle–gas partition coefficient (KQA) estimation equations ...

Jul. 3, 2012

By John Wiley & Sons, Ltd.

Development of headspace–gas chromatography–flame ionization detection procedure to determine volatile fatty acids in zoo organic waste leachates

In order to determine volatile fatty acids (short chain monocarboxylic acids with 2 to 6 carbon atoms in a molecule) in leachates formed in organic waste piles a procedure based on static headspace (HS) coupled with gas chromatography (GC) have been proposed and optimized. The conditions of HS extraction and sample introduction into a gas chromatograph as well as of chromatographic separation ...

Dec. 31, 2010

By IWA Publishing

Peroxy-acid treatment of selected PAHs in sediments

In an attempt to address some of the disadvantages of the common biotic and abiotic processes used for the degradation of Polycyclic Aromatic Hydrocarbons (PAHs), an alternative strategy utilising a primary chemical oxidative step to be combined with a biological post-treatment step was created. The degradation of α-methylnaphthalene, fluorene, phenanthrene, anthracene, pyrene and ...

Oct. 17, 2006

By Inderscience Publishers

Application of gas chromatography-mass spectrometry preceded by solvent extraction to determine volatile fatty acids in wastewater of municipal, animal farm and landfill origin

This study describes extraction of selected volatile fatty acids (VFAs) (containing from 2 up to 8 carbon atoms) with methyl-tert-butyl ether (MTBE) from polluted aqueous samples followed by separation, identification and quantification by gas chromatography coupled with mass spectrometry (GC-MS). Extraction parameters such as time and number of extractions, volume ratio, effect of acidification ...

Jan. 31, 2011

By IWA Publishing

Least-Cost Approaches to Reducing Acid Emissions

' The costs of meeting sulfur emission targets can be high. It is essential, therefore, that countries adopt policies which (a) minimize the net economic and social costs of reducing emissions to the agreed target levels, and (b) maximize the overlap between measures designed to reduce acidifying emissions and those addressing other forms of air pollution. This note discusses alternative ...

Dec. 31, 1996

By The World Bank

Photochemical degradation of 4-chlorophenol in the aqueous phase using peroxyacetic acid (PAA)

The photochemical degradation of 4-chlorophenol (4-CP) using ultraviolet irradiation (UV) of 6, 12 and 18 W with peroxyacetic acid (PAA) was studied in a batch reactor. The objective of this work was to investigate degradation and mineralization of 4-CP by PAA. The degradation efficiency increased with increasing UV input. The degradation process was also pH and initial PAA concentration ...

Nov. 19, 2012

By IWA Publishing

Photolytic degradation of chlorophenols from industrial wastewaters by organic oxidants peroxy acetic acid, para nitro benzoic acid and methyl ethyl ketone peroxide: identification of reaction products

In this investigation, chlorophenol (CP) containing industrial wastewater was remediated by ultraviolet irradiation in conjunction with organic oxidants, peroxy acetic acid (PAA); para nitro benzoic acid (PNBA); and methyl ethyl ketone peroxide (MEKP). CP mineralization was studied with regard to chemical oxygen demand (COD) and chloride ion release under identical test conditions. COD depletion ...

Mar. 18, 2014

By IWA Publishing

Leak detection in semiconductor fab gas processes

Problem Statement Often times in semiconductor fabs moisture levels are monitored to ensure that products aren’t damaged by excess moisture in the process. If there are above normal levels of moisture, pinpointing the source of that moisture can be difficult. The moisture could be evolving from impurities in gas tanks or leaks in the sampling lines. One way to avoid downtime ...

Apr. 30, 2013

By CIC Photonics

Gas cell selection for analysis of electronic gases

APIMS and FTIR remain the preferred analytical tools for monitoring impurities in the electronic specialty gases used by the semiconductor industry, although other tools such as CRDS are currently finding application in selected cases. FTIR spectroscopy offers the advantage of the simultaneous measurement of all gaseous species that exhibit dipole moment changes during vibrations at ...

Mar. 22, 2003

By CIC Photonics

Gas Monitoring for Ventilation Control and Energy Management

The growing demand for underground and enclosed parking and maintenance garages (resulting from limitations on land availability) has increased the awareness and need for proper ventilation and control systems. In addition, increased health and safety programs have only added to the concerns of toxic and combustible gases in confined or enclosed spaces. Historically, ventilation and make-up air ...

Dec. 15, 2013

By Arjay Engineering Ltd.

Sample Handling Strategies for Accurate Lead-In-Soil Measurements in the Field and Laboratory

ABSTRACT The inhomogenous lead-in-soil matrix can present serious obstacles to accurate sample collection and handling. In typical lead-in-soil measurement, particle size related errors in sampling and sample handling often exceed all other sources of error. The magnitude of error can vary widely depending on the particulate nature of the lead contaminant and the effectiveness of control ...

Jan. 28, 1999

By Thermo Scientific Niton Analyzers

Evaluation of benzene exposure in adults and urinary s-phenylmercapturic acid in children living in Adelaide, South Australia

Abstract: Benzene Exposure was evaluated in adults and children living in Adelaide, South Australia by measuring benzene and urinary s-phenylmercapturic acid (SPMA). To determine of benzene exposure in each subject the personal passive samplers was used and samples were analyzed by gas chromatography system equipped to flame ionization detector. The level of SPMA was determined by competitive ...

Apr. 19, 2006

By Center for Environment and Energy Research & Studies (CEERS)

Digester Developer Taps Natural Gas Markets

IN the late 1990s, Dan Eastman and two colleagues were researching business opportunities in the renewable energy industry. They were looking for a commercially viable technology that could take renewable energy from an experimental phase to a solid business investment. In 1999, Eastman and his partners founded Microgy, Inc., with its base in Wisconsin. The company licensed the Xergi anaerobic ...

Aug. 31, 2007

By BioCycle Magazine

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