Physical Sciences and Mathematics Commons^™

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 Oxygenated Volatile Organic Compounds Using The Thermionic Ionization Detector, Wanfang Li

Theses

A thermionic ionization detector (TID) consists of a catalytically active, low work function heated source. It responds to molecules with high electron affinity which can extract electrons from the surface of the source to form negative ions. TID has been used as selective detectors for nitrogen and phosphorous compounds (NPD). In this research, a TID has been used for selective detection of oxygenated volatile organic compounds (VOCs). The response of the TID to different oxygenated and chlorinated VOCs compounds was studied. To evaluated its performance, the analysis was done using a FID in parallel with the TID. For most of …

Solvent Sublation Of Toluene From Aqueous Phase, Mei Chen

Theses

Solvent sublation, a surface chemical technique, was used to remove toluene from aqueous solution into a layer of paraffin oil.

Analytical methods for GC determination of toluene in both gas and aqueous phase were set up. The comparison of solvent sublation and conventional air stripping on toluene removal was carried out. It was found that solvent sublation provides significant improvement over air stripping in removing toluene from water, and reduces toluene emission to the atmosphere. The toluene emissions reduction by solvent sublation are 30%-70% under different conditions. The effects of air flowrates and thickness of organic layer were studied. Increased …

Pyrolysis And Oxidation Reaction Of 1,2, Dichloroethylene In Ar; Ar And Ch4; Ar, Ch4 And O2 Mixtures, Byung Ik Park

Theses

The thermal reaction of trans-1,2-dichloroethylene (DCEE) in methane and oxygen mixtures in Ar bath gas has been studied in 10.5 mm I.D. tubular flow quartz reactors at I atmosphere pressure, isothermal temperature between 575°C and 1000°C, and times of 0.3 to 2.0 seconds.

The thermal reaction of trans-1,2-dichloroethylene in the gas phase proceeds via unimolecular HCI elimination under the reaction condition of the present experiments. The chain branching C-Cl bond fission reaction is expected to become important at the higher temperature, competing With the HCI elimination.

The decay trans- 1,2- dichloroethylene, intermediates and final product distributions varied in the absence …

Study On The Remediation Of Organic Soil Contaminated With Polychlorinated Biphenyls Using A Variable Frequency Microwave Furnace, Lili Zou

Theses

The development of new and innovative remediation technologies for soil contaminated with Polychlorinated Biphenyl (PCB) is necessary to fulfill the need of cleanup of contaminated sites. In the past eight years the Laboratory for Microwave treatment as Hazardous Substance Management Research Center has investigated the use of Microwave energy to remediate contaminated soils. A major drawback of using single frequencies of the microwave range is the non-uniformity of the electromagnetic field. In this thesis a Variable Frequency Microwave Furnace (operating between 2.40 and 7.50 GHz) is used to improve the uniformity of the field. A new method is used to …

Study Of The Leaching Of Pentachlorophenol From Treated Utility Poles, Jingyi Zhang

Theses

Pentachlorophenol ( PCP ) has been used as a preservative in wood industry over 40 years. If new regulations are passed, the disposal of used treated utility poles in landfills could be restricted because of the toxic properties of PCP. This study was undertaken to provide a better understanding of the rates and mechanisms of leaching of PCP from these poles.

Following the initial analytical method development for PCP determination, a study was done to apply and validate the method in a leaching characteristics study of PCP from Douglas Fir and Southern Pine.

The major factors which influence the leaching …

Bio-Oxidation Of A Model Voc In Air, Jeong Seop Shim

Theses

This study was performed to find a satisfactory regime of operation for the vapor phase bio-oxidation of ethyl alcohol, a model volatile organic compound (VOC), in a specially designed bioreactor. Ethanol was selected as a model compound representing bakery oven gas pollution. A spirally wound bioreactor module was used within which was immobilized a mixed bacterial culture from aerobic sludge. The activated sludge from municipal wastewater treatment plants readily attached with no pretreatment on the surface of the spiral biosupport which is a polymeric sheet.

The parameters studied were air flow rate and inlet concentrations of ethanol. Ethanol was injected, …