ISSN:1051-5658    

DOI:10.1002/rem.3440050202

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractThe Decatur County Landfill, a privately owned sanitary landfill, was shut down by Indiana officials in 1991. When the owner proved not to have the financial ability to close the site as required by law, state environmental officials turned to local businesses to remediate the landfill. In a pioneering effort at voluntary action, officials of the state, county, and city government worked in partnership with business and the local community to perform and fund closure and provide the postclosure care. This study illustrates the results that can be achieved when government and private parties work together.

ISSN:1051-5658    

DOI:10.1002/rem.3440050203

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractThousands of contaminated sites around the country never get caught in the sticky web of Superfund. Instead, they are handled by state environmental agencies under state environmental laws and rules. Generally speaking, state environmental programs appear to function much more efficiently than Superfund. But even though they are easier to work with than Superfund, state contamination cleanup programs can still be daunting. This article offers some points and suggestions for making the state process work smoothly and efficiently.

ISSN:1051-5658    

DOI:10.1002/rem.3440050204

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractRecently, some companies have begun making environmental reports and internal audits public. Other companies have chosen not to do so. The desire to engage in a critical and thorough self‐examination is often thwarted by the fear that audits and other reports may be used against a company in later litigation or administrative proceedings. However, there are some legal, regulatory, and procedural safeguards that can protect a company that chooses to make reports and audits public. This article examines these safeguards, their strengths and weaknesses, and their role in balancing self‐examination and self‐prote

ISSN:1051-5658    

DOI:10.1002/rem.3440050205

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractEnhanced methods of in‐situ remediation based on patented technology involving fluid injection with vacuum extraction have been used successfully at the Sand Creek Superfund Site in Commerce City, Colorado. Approximately 177,000 pounds of volatile organic compounds (VOCs) were removed from the subsurface in six months, two months ahead of schedule. Remediation goals were achieved on this thermally enhanced soil vapor extraction project by using vertical and horizontal wells interchangeably in vacuum or pressure service for vapor extraction, dual vacuum extraction, heated vapor reinjection, and air sparging. Although VOCs consisted of mixed chlorinated and petroleum hydrocarbons, the petroleum hydrocarbons, some in the form of nonaqueous phase liquids, had not been fully characterized. This article examines the evolution of the remedial design from that conceptualized in the Record of Decision (ROD) of the U.S. EPA, presents the rationale for the selection of alternative system components, and provides a cost analysis of the selected remedial technology, with comparisons to that of alternatives considered for use at Sand Cree

ISSN:1051-5658    

DOI:10.1002/rem.3440050206

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractSoils contaminated with wood preserving wastes, including pentachlo‐rophenol (PCP) and creosote, are treated at field‐scale in an engineered prepared‐bed system consisting of two one‐acre land treatment units (LTUs). The concentration of selected indicator compounds of treatment performance included PCP, pyrene, and total carcinogenic polycyclic aromatic hydrocarbons (TCPAHs) was monitored in the soil by taking both composited soil samples at multiple points in time, and discrete soil samples at two points in time. The mean concentration of the indicator compounds and the 95‐percent confidence interval (CI) of the composite and discrete samples agreed relatively well, and first‐order degradation rate kinetics satisfactorily represented the mean chemical concentration loss of indicator compounds in the LTU. Toxicity of the soil, as measured by MicrotoxTMassay of the soil extracts, indicated that toxicity reduction corresponded with indicator compound disappearance. No toxicity effects were observed with time in treated layers of soil (lifts) buried beneath highly contaminated lifts of newly applied soil. This indicated that vertical migration of soluble contaminants from such lifts had little effect on the microbial activity in the underlying t

ISSN:1051-5658    

DOI:10.1002/rem.3440050207

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractTraditional bioremediation approaches have been used to treat petroleum source contamination in readily accessible soils and sludges. Contamination under existing structures is a greater challenge. Options to deal with this problem have usually been in the extreme (i.e., to dismantle the facility and excavate to an acceptable regulated residual, or to pump and treat for an inordinately long period of time). The excavated material must be further remediated and cleanfill must be added to close the excavation. If site assessments were too conservative or incomplete, new contamination adulterating fill soils may result in additional excavation at some later date. Innovative, cost‐efficient technologies must be developed to remove preexisting wastes under structures and to reduce future remediation episodes. An innovative soil bioremediation treatment method was developed and evaluated in petroleum hydrocarbon contaminated (PHC) soils at compressor stations of a natural gas pipeline running through Louisiana. The in‐situ protocol was developed for remediating significant acreage subjected to contamination by petroleum‐based lubricants and other PHC products resulting from a chronic leakage of lubricating oil used to maintain the pipeline itself. Initial total petroleum hydrocarbon (TPH) measurements revealed values of up to 12,000 mg/kg soil dry weight. The aim of the remediation project was to reduce TPH concentration in the contaminated soils to a level of<200 mg/kg soil dry weight, a level negotiated to be acceptable to state and federal regulators. After monitoring the system for 122 days, all sites showed greater than 99‐percent reduction in TPH concen

ISSN:1051-5658    

DOI:10.1002/rem.3440050208

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractPneumatic fracturing is an innovative technology enhancing the removal and treatment of contaminants in moderate‐to‐low permeability formations. The main advantages are a reduction in treatment time and the extension of available in‐situ technologies to more difficult geologic conditions. Pneumatic fracturing has been successfully demonstrated in the field at a number of contaminated sites and in a variety of geologic formations. The technology is now commercially available and is being incorporated into site cleanups. This article provides an overview of the pneumatic fracturing technology, beginning with a general description of the concept and apparatus. Next, key technological considerations will be discussed including fracture initiation, fracture orientation, fracture flow, and treatable soils and contaminants. Three case studies are presented describing different applications of pneumatic fracturing. The article concludes with a discussion of cost benefits of the techn

ISSN:1051-5658    

DOI:10.1002/rem.3440050209

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractHanford tanks contain more than 60 million gallons of high‐level wastes produced by decades of extracting plutonium from irradiated uranium fuel. The wastes were concentrated to a thick slurry consistency by evaporation prior to storage to minimize space. The resulting concentrated waste properties introduced unanticipated, detrimental conditions affecting workers' and the public's health and safety and involving the release of potentially flammable gases. The released gases consist primarily of hydrogen, nitrous oxide, and ammonia.Dilution and sluicing were initially proposed to mitigate the flammable gas safety conditions. As a result of evaluations, the mechanisms and conditions that are thought to control the accumulation and spontaneous release of flammable gases were identified and confirmed. The technical rationale was established for developing operational approaches to mitigate the periodic generation of flammable gases in existing tanks and to avoid any reoccurrence of this serious safety problem during future waste management activities. The chemistry of the two highest risk tanks was examined to test the potential for reversing the conditions causing gas buildup and the consequences of sluicing without appropriate chemical conditioning. The identified mechanisms apply equally to the remaining flammable gas tanks at Hanford as well as to other waste tanks in the DOE complex, particularly those at Savannah River. Passive means of mitigating the flammable gas condition require less than 1:1 dilution, and sluicing wastes from tank 106‐C can be accomplished without creating a flammable gas condition.Carbonate equilibria reactions and their effect on aluminum speciation are largely overlooked and provided the key for explaining the episodic release of flammable gases from tank wastes. The reaction of atmospheric carbon dioxide with a sodium hydroxide‐rich waste solution produces carbonate precipitates. More importantly, this reaction lowers the pH of the waste and precipitates aluminum hydroxide as a gel. The wastes contain substantial amounts of complexing agents such as ethylene diamine tetraacidicacid (EDTA), hydroxy ethylene diamine triacidic acid (HEDTA), and their degradation products. These complexing agents stabilize the aluminum hydroxide gel together with chromium, manganese and iron hydroxides, and oxybydroxides under the resulting pH conditions. These complex species may coprecipitate and accumulate as a metastable layer in the middle and lower levels of th tank. The complexed aluminum hydroxide acts as a binding agent trapping other particulates in a microcrystalline mat. Microcrystalline particles such as sodium nitrite provide the structural strength for the mat.Once the gas accumulation below the gel layer achieves a critical buoyancy sufficient to rupture the microcrystalline mat, a gas release event occurs. The cycle of gas buildup and release continues each time the buoyancy of the trapped gas exceeds the hydrostatic pressure and the gels' plasticity modulus. Stokes Law predicts a particle settling rate in the tank of less than 50 days, well within the bistorical periodicity of GREs.Laboratory tests, forming the basis of a recent patent application, verify that large quantities of complexed aluminum hydroxide gel are produced by passing carbon dioxide through simulated waste solutions (Hobl, 1993) equivalent to those found in tank 101‐SY. It was confirmed that a simple adjustment of pH witll redissolve the gel, thereby reducing viscosity and safely facilitating continuous flammable gas release. Additional experiments were undertaken to provide a basis for understanding the role of complexed aluminum hydroxides in the CO2/NaOH/Al(OH)3(complexing agents)/NaAlO2system.This article examines a plausible mechanism for the periodic release of flammable gas and considerations for: (1) remediating existing flammable gas tanks through a combination of chemical treatment and mixer pumps; (2) diluting, combining, retrieving, and storing wastes; (3) preventing clogging of transfer lines; (4) sludge and soil washing; and (5) cribs, ponds, basins, and ground‐water cleanup. This study provides a singificant breakthrough for tank waste management by explaining key mechanisms controlling episodic release of flammable gases. The breakthrough provides the bases for removing the tanks classified as flammable gas from the wathclist and has broad operational applications with a potential for billions of dollars in cos

ISSN:1051-5658    

DOI:10.1002/rem.3440050210

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractSEAMISTTMis an innovative technology that facilitates measurements of contaminants in both vertical and horizontal boreholes. The essence of SEAMISTTMis an airtight membrane liner pneumatically emplaced inside the borehole and maintained with positive pressure. Sampling ports, absorbent collectors, and various in‐situ measuring devices can be fabricated into the liner. Small instruments and cameras can be guided through the borehole to obtain real‐time data.This article reports on the cost and performance effectiveness of this new technology. In this report, SEAMISTTMis evaluated as a tool for obtaining data on volatile organic compounds, semivolatile organic compounds, other water‐borne contaminants, and radionuclides. SEAMISTTMis also compared to traditional borehole casing, to conventional soil vapor probes, and to conventional pore‐fluid collecting lysimeters. The most cost‐ and performance‐effective applications of SEAMISTTMare shown to be those applications for which multiple characterization requirements can be combined into one SEAMISTTMmemb

ISSN:1051-5658    

DOI:10.1002/rem.3440050211

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY