Soil remediation bioremediation

In situ soil remediation with physical methods includes the in situ heating (in situ thermal treatment), ground-freezing, hydraulic fracturing, immobilization/stabilization, flushing, chemical detoxification, vapor extraction, steam extraction, biodegradation/bioremediation, electroosmosis/ electrokinetic processes, etc. 

Diels, L., Geets, J., Van Roy, S., Dejonghe, W., Gemoets, J., and Vanbroekboven, K., 2005a, Bioremediation of heavy metal contaminated sites. In Soil Remediation series 6 (Proceedings of the European Summer School on Innovative Approaches to the Bioremediation of Contaminated Sites Soil Remediation series N°6, ed. Faba F., Canepa... 

T0458 Kenox Technology Corporation, Wet Air Oxidation T0461 Kinit Enterprises, Trozone Soil Remediation System T0470 Lambda Bioremediation Systems, Inc., Bioremediation... 

T0585 Oxidation Systems, Inc., HYDROX Oxidation Process T0598 Pelorus EnBiotech Corporation, Slurry-Phase Bioremediation T0602 Pet-Con Soil Remediation, Inc., Thermal Desorption T0606 PHYTOKinetics, Inc., Phytoremediation T0607 Phytoremediation—General... 

The process is applicable to sludges, sediments, and liquids and to in situ soil remediation. The DETOX process operates most effectively at soil temperatures between 60 and 95°F (16 and 35°C). The bioremediation process stops at soil temperatures below 32°F (0°C) and at soil temperatures above about 140°F (60°C). 

Industrial Cleaning Facility, California. The PetroClean bioremediation system remediated 4600 m of contaminated soil at a cost of approximately 59/m. The system also recovered and treated an additional 5.7 million liters of contaminated groundwater at no additional cost (D12884R, pp. 598-599). 

The Oil Snapper soil remediator is a nutrient formulation designed to enhance the activity of soil microbes, leading to faster bioremediation of petroleum hydrocarbons. It can be used with either indigenous soil microbes or added commercial microbes and is absorbent to prevent runoff and control odors when applied to spills. Oil Snapper may be used to improve bioremediation processes in treatment cells, biopiles, landfarms, or for in situ bioremediation. 

A. Davis, S. Kamp, G. Fennemore et al., A Risk-based Approach to Soil Remediation Modeling, Envir. Policy Anal. 31(11), 521A-525A (1997). A.M. Thayer, Bioremediation Innovative Technology for Cleaning up Hazardous Waste, Chem. Eng. News, 69(34), 23-44, Aug. 26 (1991). 

We have considered already (see Chapter 6) soil remediation after release and accumulation of some types of pollutant like excessive salt accumulation and accidental release of oil products. In this subchapter we will further discuss the problems of site remediation, including bioremediation, after accumulation and release of heavy metals and persistent organic pollutants. 

Remediation aetivities at North Cavaleade ineluded the installation, operation, and elosure of a bioremediation system to treat eonta-minated soil. 

A further application of the manipulation of microbial activity in the rhizo-sphere is their potential to remediate contaminated land. Bioremediation involves the u.se of microorganisms that break down contaminants. Radwan et al. (255) found that the soil associated with the roots of plants grown in soil heavily contaminated with oil in Kuwait was free of oil residues, presumably as a result of the ability of the resident rhizosphere microflora to degrade hydrocarbons. The use of plants as a means to accumulate pollutants such as heavy metals (256,257) to degrade hydrocarbons and pesticides (255) is already widely implemented and has proven to be successful. In some cases, there is no doubt that it is the plant itself that is responsible for the removal of the contaminants. However, in most... 

Biological activity can be used in two ways for the bioremediation of metal-contaminated soils to immobilize the contaminants in situ or to remove them permanently from the soil matrix, depending on the properties of the reduced elements. Chromium and uranium are typical candidates for in situ immobilization processes. The bioreduction of Cr(VI) and Ur(VI) transforms highly soluble ions such as CrO and UO + to insoluble solid compounds, such as Cr(OH)3 and U02. The selenate anions SeO are also reduced to insoluble elemental selenium Se°. Bioprecipitation of heavy metals, such as Pb, Cd, and Zn, in the form of sulfides, is another in situ immobilization option that exploits the metabolic activity of sulfate-reducing bacteria without altering the valence state of metals. The removal of contaminants from the soil matrix is the most appropriate remediation strategy when bioreduction results in species that are more soluble compared to the initial oxidized element. This is the case for As(V) and Pu(IV), which are transformed to the more soluble As(III) and Pu(III) forms. This treatment option presupposes an installation for the efficient recovery and treatment of the aqueous phase containing the solubilized contaminants. 

Tables 24.13 and 24.14 summarize performance data for the 35 completed and 38 ongoing in situ bioremediation projects. The concentration of MTBE in groundwater prior to treatment was as high as 870,000 pg/L and as low as 10 pg/L. The data show that bioremediation (either alone or in combination with other technologies) has been employed to remediate MTBE in groundwater and soil to concentrations <50 pg/L and has achieved MTBE concentration reductions >99%. The median project duration for the 20 completed sites ranged from 6 months to 1 year.

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