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Full-Text Articles in Physical Sciences and Mathematics

Development Of Standard Operating Procedure With Modified Method To Quantify Benzene And Other Volatile Organic Compounds In Air Samples Using Gas Chromatography, Heather Hall Aug 2021

Development Of Standard Operating Procedure With Modified Method To Quantify Benzene And Other Volatile Organic Compounds In Air Samples Using Gas Chromatography, Heather Hall

Electronic Theses and Dissertations

Stephen F. Austin State University (SFASU) Department of Environmental Science has recently invested in a gas chromatograph which can be used to analyze air samples for volatile organic compounds (VOCs) such as benzene, toluene, ethylbenzene, and xylenes (BTEX). The goal of this project was to develop a standard operating procedure (SOP) and modify the current method for the detection of VOCs associated with oil and gas drilling activity to accommodate the equipment and capabilities of SFASU Environmental Assessment Lab. This study aims to provide the framework for future research in air quality monitoring in the Eagle Ford Shale area. An …


Stable Bromine Isotope Signature Of Bromoform From Enzymatic And Abiotic Formation Pathways And Its Application In Identifying Sources Of Environmental Bromoform In The Damariscotta River, Chengyang Wang Jan 2018

Stable Bromine Isotope Signature Of Bromoform From Enzymatic And Abiotic Formation Pathways And Its Application In Identifying Sources Of Environmental Bromoform In The Damariscotta River, Chengyang Wang

Honors Theses

Bromoform is a major source of atmospheric bromine. Most bromoform is produced by marine organisms including macroalgae and phytoplankton, using the enzyme bromoperoxidase (BPO). Bromoform can also be a byproduct of industrial processes such as water disinfection. Identifying sources of environmental bromoform is still a challenge. A novel technique of using quadrupole mass spectrometry coupled to a gas chromatography (GCqMS) was developed and optimized for Br isotope analyses. The study shows that GCqMS in single ion monitoring (SIM) mode can measure 81Br with precision of around ±0.7‰ (60pmol bromoform injected). This study aims to investigate stable Br isotopes of bromoform …


Continuous Monitoring Of Volatile Organic Compounds In Air Emission Using Membrane Extraction Microtrap Gc System, Xin Zhang Oct 1994

Continuous Monitoring Of Volatile Organic Compounds In Air Emission Using Membrane Extraction Microtrap Gc System, Xin Zhang

Theses

A novel method for continuous monitoring volatile organic compounds (VOCs) in air at trace level is presented. A membrane module and a microtrap were used along with gas chromatographic analysis. The membrane module consisted of a bundle of silicone rubber hollow fibers and separated the VOCs from the gaseous stream. The microtrap which is a very small adsorbent trap played the roles of preconcentrator and injector. The VOCs selectively permeate across the membrane into a strip gas in the membrane module. Before entering the GC column, the VOCs are trapped and concentrated by the microtrap. Desorption of the VOCs is …


Measurement Of The Removal Of Selected Vocs From A Municipal Treatment Plant, Hong Yu Dec 1991

Measurement Of The Removal Of Selected Vocs From A Municipal Treatment Plant, Hong Yu

Theses

Industrial wastewater contains a variety of volatile chemical constituents. The large majority of the volatiles are organics. Many of these volatile or¬ganic compounds (VOCs) end up in the effluent to wastewater treatment plants. It is necessary to estimate the emission of the VOCs from sewerage plants in order to study the fate of these volatile organic compounds.

This study focuses on the estimation and comparison of the emission of 28 volatile organic compounds from the water and air in four operation units of Linden Roselle Sewerage Authority (LRSA) wastewater treatment plant. The removal rates of these target compounds have been …


Liquid-Vapor Equilibria And Henry's Law Constants For Volatile Organics In Surfactants, Qianping Peng May 1991

Liquid-Vapor Equilibria And Henry's Law Constants For Volatile Organics In Surfactants, Qianping Peng

Theses

We present liquid vapor equilibria data and Henry's law constants for Methyl-ethyl Ketone, Toluene, Butyl Acetate, Acetone and i-Propanol in surfactants: Octylphenyl Decaethoxylate, Sorbitan Monooleate and Sodium Sulfonate at temperatures of 20 to 70 C.

The objective of this study is to determine the effect of applying surfactant absorption technique (neat surfactants) to volatile organic compounds (VOC's) for the removal of these species as organic vapors from air emission streams.

Liquid/vapor equilibrium data are presented as curves in several different ways:

i. Each individual VOC at four temperatures between 22 C to 70 C in the respective surfactants Octylpenyl Decaethoxylate, …


Degradation Of Refractory Organic Pollutants In Tar, Water And Soil Matrices By Ozone Or Hydrogen Peroxide With Ultraviolet Light, Liang-Jiun Uang Jan 1990

Degradation Of Refractory Organic Pollutants In Tar, Water And Soil Matrices By Ozone Or Hydrogen Peroxide With Ultraviolet Light, Liang-Jiun Uang

Theses

The objective of this research is to develop a method to degrade refractory Tar materials, higher molecular weight 3-5 ring Poly Aromatic Hydrocarbons (PAH's) or degrading these highly refractory PAH structures so that they are amenable to further treatment by biological or chemical methods. The process utilized to achieve this is to treat contaminated soils or tar materials with hydrogen peroxide or ozone plus ultraviolet light. Analysis of 27 specific PAH's was done by gas chromatograph (Flame Ionization Detection) for the reactants and products. The contaminated soil showed significantly lower levels of these PAH's after treatment.


Organics In Ambient Air By Collection On Tenax, Thermal Desorption,And Capillary Chromatography With Parallel Fid/Ecd Analysis, Chih-Hsiang Liao May 1989

Organics In Ambient Air By Collection On Tenax, Thermal Desorption,And Capillary Chromatography With Parallel Fid/Ecd Analysis, Chih-Hsiang Liao

Theses

Volatile organics in ambient air were regularly collected on Tenax cartridges at high (10 ml/min) and low (5 ml/min) intake flows. These Tenax samples were analyzed by using a Tekmar Automatic Thermal Desorber and capillary GC system with parallel flame ionization (FID) and electron capture detectors (ECD). A series of quality assurance procedures has been established to improve and assure the accuracy and precision of sample collector and analysis. These procedures relate to performance of the Tekmar thermal desorber, recovery efficiency from the Tenax, and include studies on breakthrough and co-elution. The results demonstrate (1) that from ambient air data …