Pollution removal from groundwater

The use of extraction as we have described it to remove pollutants from groundwater would be unworkable. The concentrations are so low that large quantities of water-insoluble solvents would have to be used and recovered. Inasmuch as the recovery of the solvents would be inexact, more pollutants would doubtless be released into the environment than would be removed. We may have found a solution to this puzzle by using a solvent that does not have to be recovered in the typical sense of the word. 

Takiyama MK, Chu CS, Huang YC, Huang CP, Huang HS. The removal of priority pollutants from groundwater by advanced oxidation processes. Hazard Ind Waste 1994 26 178-185. 

Natural attenuation by itself, however, often is not sufficient to achieve a desired extent or rate of contaminant removal from an aquifer. In these instances, one remedial option may be to enhance the natural rate of biodegradation of pollutant chemicals in the aquifer. This strategy, called in situ bioremediation, is considered to be one of the most attractive remedial techniques from a cost perspective, because many of the high costs associated with pumping and treating groundwater or excavating contaminated aquifer material are avoided. Furthermore, the potential exposure of cleanup workers to pollutant chemicals is reduced if many of the contaminants are mineralized while still in the aquifer. 

Elliott, H.A. Peters, R.W. "Decontamination of Metal-Polluted Soils Using Chelating Agents, In Removal of Heavy Metals from Groundwaters CRC Press, Inc. Boca Raton, FL, (in press). 

F.-G. Simon and T. Meggyes, Removal of Organic and Inorganic Pollutants from Groundwater Using Permeable Reactive Barriers Part 1—Treatment Processes for Pollutants, Land Contam. Reclam., 2000, 8, 103-116. 

Boni R, Pappa R, Contarini S (2006) Urban gasoline stations new techniques for early leak detection from USTs and removal of low concentration pollutants from groundwater. In NATO/CCMS pilot study meeting, 4-7 June, Athens, Greece. Available online at http //www.cluin.org/athens/ last visited 20 April 2007... 

The electrokinetic technology for the remediation of soils, sediments, and groundwater relies on the application of a low-intensity electric field directly to the soil in the polluted site. The effect of the electric field mobilizes ionic species that are removed from the soil and collected at the electrodes. At the same time, the electric field provokes the mobilization of the interstitial fluid in the soil, generating an electroosmotic flow toward the cathode. The electroosmotic flow permit the removal of soluble contaminants. The success of the electrokinetic process rely on the effective extraction and solubilization of the contaminant and on their transportation toward the electrodes, where they can be collected, pumped out, and treated. Many studies have been carried out to determine the influence of the operating conditions and the effect of the soil and contaminant nature in order to improve the applicability and effectiveness of the electrokinetic treatment. 

Groundwater is vulnerable to pollution by chemicals carried by rainwater, leaching from waste sites or from waste water carrying industrial or agricultural effluent. Treatment of drinking water may remove some, but not all, of these contaminants. Some polycarbonate or metal water pipes that are lined with epoxy resin lacquers may release bisphenol A. 

The Macro porous polymer (MPP) system is an ex situ technology designed to remove hydrocarbon pollutants from process water, groundwater, and wastewater. This technology uses a patented, porous polymer containing an immobilized extraction fluid that assimilates the hydrocarbons into the polymer structure. The particles are regenerated with an in situ heating cycle, and the contaminants are recovered for reuse, recycle, or disposal. 

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