In Situ Processes

Under the appropriate conditions, bioremediation can be successfully accomplished in situ that is, soil microorganisms may be stimulated and or added to treat low-to-moderate concentrations of organic contaminants in place, without excavating or otherwise disturbing contaminated soil. The reaction zone may be a soil horizon at or near the surface, or may occur in an aquifer many feet below the surface. In some situations bioremediation can occur by the action of the indigenous microbial...

Introduction

Pump-and-treat systems have found widespread application at affected sites and have become a standard technology for cleanup of contaminated groundwater (see chapter 6). Several drawbacks are noteworthy to this approach, however. A pump-and-treat system requires an external energy source that becomes costly when operated over long periods. Also, because much of the water initially extracted is uncontaminated, pump-and-treat may waste groundwater resources. Even when properly operated,...

Plasma Centrifugal Furnace

The plasma centrifugal furnace (PCF) is an ex situ technology that uses heat generated from a plasma torch to melt and vitrify solid feed material. Organic contaminants are vaporized and decomposed by the intense heat of the plasma and are oxidized by the air used as the plasma gas before passing to the off-gas treatment system. Metal-containing solids are vitrified into a monolithic nonleachable mass (U.S. EPA 1992). Vitreous material occurring after ISV treatment U.S. Department of Energy....

Pneumatic Fracturing And Hot Gas Injection

As discussed in chapter 9, soil vapor extraction (SVE) has been a popular method for the removal of volatile hydrocarbons from the vadose zone. A primary limitation to SVE technology, however, is that the vadose zone formation must be sufficiently permeable for air to flow and mobilize the volatile contaminants into the airstream. A method has been devised to facilitate the cleanup of soil and rock formations with poor air permeability, for example, shales and clay. The method involves...

Phytoremediation Chapter 12 Phytoextraction Of Metals

Phytoextraction involves the use of hyperaccumulating plants to transport metals from the soil to concentrate them into roots and aboveground shoots. Following harvest of the extracting crop, the metal-rich plant biomass can be processed to recover the contaminant (e.g., valuable heavy metals, radionuclides). If recycling the metal is not economically feasible, the small amount of ash (compared to the original plant biomass or the large volume of contaminated soil) can be disposed of...

Lethal Cyanide Spill in Ghana Outrages Gold Mining Communities Environment News Service July 5 2006

A cyanide spill in Ghana has posed serious threats to local populations and wildlife. The release has caused numerous fish kills and has made many people sick. This is not the first time the Bogosu Gold Ltd. Company has harmed the local environment, and citizens in surrounding villages are demanding an environmental audit. The cyanide was specifically used for extracting gold from rock tailings. The contaminated tailing apparently spilled into local soils and water. The company then applied...

Mercury

Mercury (Hg) is a chalcophile and, in unweathered rocks is commonly found as cinnabar, HgS. Sources of soil contamination with Hg include metal processing industries, certain chemical works (especially chloralkali), and the use of fungicides containing Hg. Sewage sludges and other wastes may also be sources of Hg contamination. Mercury has been used in the gold amalgamation process in gold mining in the Brazilian Amazon basin (Olivera et al. Malm et al. 1990). Common secondary Hg sources are...

Isolation Containment Chapter

Isolation involves the physical segregation of subsurface contaminants from noncontaminated soil and groundwater. A number of systems are available to isolate the affected area so that contaminants are contained, either for permanent isolation or for removal or treatment at a later date. Specific systems that can effectively limit the spread of the contaminant include diverting the flow of groundwater subsurface barriers placed in the direction of flow to control lateral spread and placement of...

Reductive Treatment of Inorganic Anions

Anions and oxy anions of chromium (Cr), arsenic, selenium, technetium, and antimony are significant groundwater contaminants. Because of their negative charge, such anionic species are typically repulsed by negatively charged colloidal surfaces that usually predominate in soil and aquifers under neutral pH conditions (see chapter 4). The resulting high solubility of such anions results in a potential hazard to water supplies. PRB technology is often appropriate for the treatment and removal of...

Chromium

Significant sources of chromium (Cr) to the biosphere include the chemical manufacturing industry and combustion of fossil fuels (natural gas, oil, and coal). Other sources include wastewaters from electroplating, leather tanning, and textile industries incineration of municipal solid waste (MSW) and sewage sludge cement manufacture and emissions from air conditioning cooling towers that use Cr compounds as rust inhibitors (U.S. EPA 1994 Nriagu 1988). The variability in the oxidation states of...

Chemical And Physical Properties Of Fuels And Petrochemicals

From the standpoint of delineation of a contaminant plume and prognosis for success in remediation, important physical properties of petroleum Table 3.4. Uses of alkanes, alkenes, aromatics, and related hydrocarbons in petrochemical applications Table 3.4. Uses of alkanes, alkenes, aromatics, and related hydrocarbons in petrochemical applications Manufacture of plastic resins including phenolic, urea, and melamine resins. Bakelite, Formica, methanol Manufacture of solvents, refrigerants, and...

Flushing Metals From Soil

Bacteria Biosorption

Metals at contaminated sites occur in complex forms, and mobility is controlled by numerous chemical and physical phenomena including soil type, pH, cation exchange capacity, particle size, and the presence of other inorganic or organic compounds (see chapter 2). Many of these factors are interdependent (Reed et al. 1995). Metal removal efficiencies during soil flushing depend not only on soil characteristics but also on metal concentration, chemistry of the metal(s), extractant chemistry, and...

Case History

The Selma Pressure Treating (SPT) site was used for the chemical treatment of lumber since 1942. The site is located southeast of Fresno, California, in the San Joaquin River Valley. The SPT site covers 18 acres however, the actual wood-treatment area measures 3 to 4 acres. The site is located less than a quarter-mile from homes and businesses. Ground-water resources near the site are classified as a beneficial use, sole-source aquifer. This aquifer provides the domestic water supply for...

Slurry Biodgradation

In a slurry biodegradation system, contaminated soil or sludge is removed from the affected area and mixed with water to produce a slurry. This slurry is then continuously mixed and aerated within a reactor vessel or lined lagoon. Decomposition of organic contaminants takes place usually via aerobic processes. Slurry biodegradation has been shown to be capable of treating soils with contaminant concentrations up to 250,000 mg kg. The method has been used to treat a range of organic contaminants...

Electrokinetic Remediation

Electrokinetic remediation, also referred to as electrokinetic soil processing, electromigration, electrochemical decontamination, or electroreclamation, involves the application of low-density direct current between electrodes placed in the soil to mobilize contaminants that occur as charged species. This is therefore a separation and removal technique for radionuclides, metals, and some organic contaminants from saturated or unsaturated soils, slurries, and sediments. Electrodes can be...

Figures

Illustration of carding, drawing, and roving that appeared in History of Cotton Manufacture, Edward Baine, 1835 2 Figure 1.2. Smog event over urban skyline 3 Figure 1.3. Leaking underground storage tanks removed from an abandoned petroleum refinery 6 Figure 1.4. The Love Canal (N.Y.) neighborhood during cleanup activities in the late 1970s 7 Figure 1.5. Valley of the Drums, Kentucky 8 Figure 1.6. Kin-Buc Landfill, New Jersey 9 Figure 1.7. Indiscriminate disposal of hazardous wastes...

Liquid Phase Bioremediation

There are situations in which it is advantageous to recover contaminated groundwater and treat it in an aboveground bioreactor. Microorganisms are encouraged to proliferate and are retained under optimized process conditions. Treated water is later returned to the site. The original principles of design originate from municipal and industrial wastewater treatment facilities. Several technologies are well adapted to the treatment of contaminated groundwater. However, some of the theory behind...

Land Treatment

Land treatment techniques for bioremediation (landfarming, biorecla-mation, biopiles) are commonly used for treatment of contaminated soil but certain chemical plant sludges, industrial wastes, and petroleum waste sludges have also been added to soil for treatment. Contaminants most commonly treated are petroleum compounds including fuel, lubricating oil, and organic wood preservatives. Other applications include soil contaminated with coal tar wastes, pesticides, and explosives. Until passage...

Glossary of Terms

Accumulator Plant that absorbs high concentrations of an element or compound into tissue with no apparent detrimental effect. Acid A liquid or solid that donates a proton (H+) to another substance. A substance that causes destruction to skin tissue at the site of contact or that corrodes steel. Liquids possess a pH of less than 7.0. Actinomycetes A group of heterotrophic, mostly filamentous aerobic microorganisms. Activated carbon Pyrolyzed carbonaceous material used to remove potentially toxic...

Installation And Configuration Of Prbs

Funnel And Gate

The PRB is installed across the flow path of a contaminant plume (Fig. 10.2). The reactive media is installed in order to be in intimate contact with the surrounding aquifer material. The reactive treatment zone either decomposes the contaminant or restricts its movement via employing reac-tants and agents including zero-valent iron (ZVI) or other reduced metals, zeolites, humic materials, chelating agents, sorbents, active microbial cells, and others. Several variations of PRB configurations,...

References

F. Mayland. 1999. Selenium uptake by plants from soils amended with inorganic materials. Journal of Environmental Quality 27 1218-27. Anderson, T. A., and B. T. Walton. 1992. Comparative Plant Uptake and Microbial Degradation of Trichlorethylene in the Rhizospheres of Five Plant Species Implications for Bioremediation of contaminated surface Soils. Oak Ridge, TX Oak Ridge National Laboratory. Environmental Science Division, Pub. 3809. ORNL TM-12017. Arapis,...

Questions

How can it be applied to solidified stabilized contaminated soil material 2. Locate ASTM standards for concrete testing. How do you expect solidified soil to differ from Portland cement in terms of UCS and other properties 3. What, if any, is the effect of the presence of oily wastes on S S of metal-contaminated soil 4. Ideally, Cr(VI) should be reduced to Cr(III) prior to S S. Explain why this is so. 5. Volume expansion inevitably results from S S treatment....

Case History 1

The French Limited Superfund Site in Crosby, Texas, is a former industrial waste storage and disposal facility measuring 22.5 acres. Between 1966 and 1971, approximately 70 million gal of industrial wastes from local petrochemical companies were disposed at the site. Wastes included tank bottoms, pickling acids, and off-specification product from petroleum refineries and petrochemical plants. Most of the waste was deposited in an unlined, 7.3-acre lagoon. Wastes were also processed in tanks and...

Release Considerations

An initial step in the phase II investigation is to ascertain what contaminants were released. Knowledge of the type of the product released, its physical and chemical properties, and its major chemical constituents provides insight into subsurface behavior as well as the hazard potential to public health and environmental receptors. Petroleum products include a variety of fuel types, each having different physical and chemical properties. These properties must be known or estimated to make a...

Brownfields

EPA Region 5 defines brownfields as abandoned, idled or underused industrial and commercial sites where expansion or redevelopment is complicated by real or perceived environmental contamination that can add cost, time or uncertainty to a redevelopment project. The U.S. Office of Technology Assessment definition includes a site whose redevelopment may be hindered not only by potential contamination, but also by poor location, old or obsolete infrastructure, or other less tangible...

A Note About Feo Longevity

The lifespan of effective ZVI-based PRBs is relatively unknown. Cost effectiveness is directly linked to longevity of the PRB reactant media. The longevity of ZVI is potentially reduced by three phenomena (Morrison et al. 2002) (1) dissolution of the iron (2) mineral precipitation leading to significant reduction in permeability and (3) passivation of the ZVI (i.e., the changing of the chemically active surface of the metal to a much less reactive state) resulting from alteration of Feo...

Toxic Home Costs Orkin Millions Tampa Tribune November 21 1998

Orkin Exterminating Co. illegally used the pesticide chlordane for termite control after it was banned in 1988. Chlordane was used from 1948 to 1988. Chlordane cannot be decomposed by the human body, can accumulate, and can affect the neurological, reproductive, and immune systems. Orkin treated a historic home with chlordane in 1993. The house was subsequently condemned for occupation due to chlordane contamination. The couple that lived in the house was awarded 2 million in settlement for the...

Cost Analysis of Remediation Projects

Based on the technical information presented in the previous chapters, it should be obvious that the cost of bringing a remediation project to completion will vary over a wide spectrum. Important factors that potentially affect project costs include concentration of contaminants in the affected media required cleanup levels, hydrogeologic conditions, completion schedules, and permit fees for example, for treatment of a specific media, treatment of off-gases, disposal of treated soil, etc. . As...

List of Acronyms and Abbreviations

ASTM American Society for Testing Materials BTEX benzene, toluene, ethylbenzene, and xylene CERCLA Comprehensive Environmental Response, Compensation, CESQG conditionally exempt small-quantity generator CFR Code of Federal Regulations DNAPL dense nonaqueous phase liquid DOT U.S. Department of Transportation DRE destruction and removal efficiency EPA U. S. Environmental Protection Agency HCl hydrochloric acid or hydrogen chloride Occupational Safety and Health Administration perchloroethylene...