Download or read book Identification and Removal of Trichloroethylene Contamination A Case Study at Wright Patterson Air Force Base written by Gregory A. Butterfield (Captain USAF.) and published by . This book was released on 1991 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Identification and Removal of Trichloroethylene Contamination A Case Study at Wright Patterson Air Force Base written by Gregory A. Butterfield and published by . This book was released on 1991 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this thesis was to determine the parameters associated with installing monitoring wells to detect trichloroethylene contamination, and to determine what emphasis or weights were placed on the nine National Contingency Plan criteria to select a treatment method that would remove trichloroethylene. The results of this study should help installation restoration project officers understand what parameters should be investigated for determining the number and placement of monitoring wells during a remedial investigation for trichloroethylene. The results of this study should also give some insight into what emphasis should be placed on the nine National Contingency Plan criteria.

Download or read book Measuring the Removal of Trichloroethylene from Phytoremediation Sites at Travis and Fairchild Air Force Bases written by Heather A. Klein and published by . This book was released on 2011 with total page 113 pages. Available in PDF, EPUB and Kindle. Book excerpt: Past use of trichloroethylene (TCE) as a degreasing solvent for aircraft maintenance has resulted in widespread groundwater contamination at Air Force Bases around the world. Travis AFB in California and Fairchild AFB in Washington are evaluating phytoremediation as a treatment option, since trees have been reported to take up dissolved TCE from shallow groundwater and volatilize it to the atmosphere while enhancing the volatilization of TCE from surrounding soil. Previous studies generally focused on the identification of removal mechanisms. The emphasis of this research was to quantify total TCE removal from phytoremediation demonstration plots at Travis and Fairchild AFBs. Tree cores, collected using an increment borer and analyzed using headspace GC/MS, were used to determine the relative TCE concentrations within the plume beneath the trees and to estimate the mass of TCE in each tree. To estimate the iv volatilization of TCE from leaves, a small section of tree branch was placed inside a flow-through glass chamber. Continuous air flow through the chamber maintained normal transpiration and temperature. Air exiting the chamber was sampled for TCE using Tenax® tubes. Humidity probes placed at the chamber entry and exit were used to estimate transpiration. Volatilization of TCE from tree trunk and soil surfaces was measured by enclosing a section of trunk or ground surface within a small stainless steel chamber. Fans in the chamber mixed the air that was recirculated through Tenax® tubes to continuously remove TCE. After a measured time interval, the Tenax® tubes were analyzed for TCE by thermal desorption GC/MS. By using a Thiessen polygon method, the removal of TCE was estimated to be 839 g/yr at Travis and 18 g/yr at Fairchild with the majority from leaf and soil volatilization. Soil surface volatilization of TCE was greater inside the planted areas than outside the planted areas, indicating that the trees enhance this removal by this mechanism. Based on these estimates phytoremediation removed 5 and 50% of the mass of TCE in the groundwater at Fairchild and Travis Air Force sites, respectively.

Download or read book Quantifying the Removal of Trichloroethylene Via Phytoremediation a Hill Air Force Base Utah Operational Unit 2 Using Recent and Historical Data written by J. Oliver Diamond and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Trichloroethylene (TCE) is a carcinogenic, chlorinated volatile organic compound that was commonly used as a degreasing solvent for aircraft maintenance at many US Air Force bases. Past improper disposal of TCE has resulted in contaminated groundwater at many of these facilities. Phytoremediation, defined as the use of plants and their associated microorganisms to stabilize or remove contamination, has been implemented as part of a TCE groundwater cleanup at Travis Air Force base near Sacramento, CA and is being considered as a remediation option at other bases. Volatilization of TCE from leaves and the surface of the soil near the trees were shown to be the most important removal mechanisms at the Travis site. Past studies conducted on indigenous trees growing above TCE contaminated groundwater at several Hill Air Force Base (HAFB) locations have also shown that TCE is taken up and volatilized by the trees. However, phytoremediation has not been implemented, in part because of the difficulty in predicting the potential effectiveness of TCE removal over time. Flow through or recirculating chambers were used to quantify the amount of TCE removed by volatilization through leaf, trunk, and soil surfaces. Tenax4́Ø sorbent tubes, used to collect TCE from the chambers, were analyzed by thermal desorption gas chromatography/mass spectrometry. Tree cores were collected using an incremental borer and analyzed by headspace GC/MS to quantify the TCE mass contained in the trees. Field measured transpiration stream concentrations (TSC) and groundwater data were used to calculate transpiration stream concentration factors (TSCF) for TCE. Comparing current and historical data, it was found that trees reach a steady state TSCF value of 0.26 after about 15 years. Using this information, it was predicted that a phytoremediation plot containing 40 poplar trees located in a seep area within HAFB OU2 would remove 4.82 kg of TCE annually. A larger plot covering the entire hillside above this seep (160 trees) could remove up to 19.28 kg of TCE annually, once trees reach a steady state TSCF.

Download or read book Government Reports Announcements Index written by and published by . This book was released on 1992 with total page 836 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Environmental Contamination Department of Defense Activities Related to Trichloroethylene Perchlorate and Other Emerging Contaminants written by and published by DIANE Publishing. This book was released on 2007 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Removal of Trichloroethylene Contamination from Drinking Water at a USAF Installation written by Robert G. Perry and published by . This book was released on 1978 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: Trichloroethylene (TCE), a solvent previously used by numerous USAF industrial activities as a degreasing agent, was discovered in relatively high concenrations in the drinking water distribution system at one USAF installation. Various USAF agencies and the U.S. Environmental Protection Agency cooperated in research work to determine the most economically feasible method to remove TCE from the water supply. This report documents the historical aspects of the problem and the results of this phase of the research. (Author).

Download or read book Distribution and Movement of Trichloroethylene in Ground Water in the Tucson Area Arizona written by S. A. Leake and published by . This book was released on 1987 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Evaluation of Pumping Strategies for Capturing Aqueous Tetrachloroethylene and Trichloroethylene at Wright Patterson Air Force Base Ohio written by Keith W. Henn and published by . This book was released on 1996 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Preliminary Assessment of Using Tree Tissue Analysis and Passive Diffusion Samplers to Evaluate Trichloroethene Contamination of GroundWater at Site SS 34N McChord Air Force Base Washington 2001 written by and published by DIANE Publishing. This book was released on with total page 21 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Development of Packed Tower Air Strippers for Trichloroethylene Removal at Wurtsmith Air Force Base Michigan written by Randy L. Gross and published by . This book was released on 1985 with total page 89 pages. Available in PDF, EPUB and Kindle. Book excerpt: Packed-tower air stripping was researched and developed to treat trichloroethylene (TCE)-contaminated groundwater at Wurtsmith Air Force Base (Oscoda), Michigan. A leaking underground storage tank has caused a 1000 meters (3200 feet) long, 500 meters (1600 feet) wide, and 18 meters (60 feet) deep plume, with a maximum concentration approaching 10,000 ppb. While activated carbon could have produced treated water with an effluent TCE concentration below Michigan's 1.5 ppb discharge standard, the projected $1.5 million capital cost and the annual $400,000 operating and maintenance costs were prohibitive. At the request of HQ Strategic Air Command, the Engineering and Services Center investigated alternate groundwater treatment techniques. Laboratory studies were performed to determine removal efficiencies and mass transfer coefficients for TCE on 16 mm (5/8-inch) (and 25 mm (1-inch)) polypropylene Pall rings at various liquid and air flows, and at temperatures ranging from 10-30 C (50-86 F). Performance equations and removal efficiencies were combined to provide relationships for determining the required packing volume. Based on these studies, twin packed-tower air strippers were built onsite at Wurtsmith AFB. The strippers were performance-tested from May 1982 to May 1983, with removal efficiencies averaging better than 99.9 percent. Originator supplied keywords include: Aeration, Trichloroethylene, TCE, Pall Rings, Groundwater Treatment, Volatile Organics, Biological Growth, Air Stripping, Biological Degradation, Trichloroethene.

Download or read book A Case Study of Reductive Dechlorination of Trichloroethylene contaminated Groundwater at Offutt AFB by Use of an Organic Composite Biowall Lasagna Treatment written by Brian J. Christ and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Toxicological Profile for Trichloroethylene written by and published by . This book was released on 1997 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Procedures for Addressing Uncertainty and Variability in Exposure to Characterize Potential Health Risk from Trichloroethylene Contaminated Ground Water at Beale Air Force Base in California written by and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Conservative deterministic, screening-level calculations of exposure and risk commonly are used in quantitative assessments of potential human-health consequences from contaminants in environmental media. However, these calculations generally are based on multiple upper-bound point estimates of input parameters, particularly for exposure attributes, and can therefore produce results for decision makers that actually overstate the need for costly remediation. Alternatively, a more informative and quantitative characterization of health risk can be obtained by quantifying uncertainty and variability in exposure. This process is illustrated in this report for a hypothetical population at a specific site at Beale Air Force Base in California, where there is trichloroethylene (TCE) contaminated ground water and a potential for future residential use. When uncertainty and variability in exposure were addressed jointly for this case, the 95th-percentile upper-bound value of individual excess lifetime cancer risk was a factor approaching 10 lower than the most conservative deterministic estimate. Additionally, the probability of more than zero additional cases of cancer can be estimated, and in this case it is less than 0.5 for a hypothetical future residential population of up to 26,900 individuals present for any 7.6-y interval of a 70-y time period. Clearly, the results from application of this probabilistic approach can provide reasonable and equitable risk-acceptability criteria for a contaminated site.

Download or read book National Exposure Registry written by United States. Agency for Toxic Substances and Disease Registry and published by . This book was released on 1994 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Government reports annual index written by and published by . This book was released on 199? with total page 1388 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Occupational Exposure to Trichloroethylene written by National Institute for Occupational Safety and Health and published by . This book was released on 1973 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt: