Permeable Reactive Barrier PRB System

Various remediation techniques have been developed and adopted to clean up contaminated groundwater. Among them, the PRB system has been considered as 

The PRB system works best at sites with loose, sandy soil and with a steady flow of groundwater. The depth of pollution that can be treated by the PRB system should be within 50ft. The remediation by the PRB system can be effective (i.e. faster) and economic (i.e. cheaper) compared to other methods as there is no need to pump contaminated groundwater (US EPA, 2001). 

4 COMBINED SYSTEM OE ELECTROKINETICS AND PERMEABLE REACTIVE BARRIER 

The reactive materials placed in the PRB trench are not harmful to the groundwater as well as to people. Tlie contaminated groundwater can be cleaned underground, and therefore people can avoid contact with pollutants. The remediation using 

PRB usually needs to remove some soil, which may be contaminated, when digging the trench. 

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Based on 1997 data, the estimated cost of a permeable reactive barrier (PRB) system ranged from approximately 405,000, corresponding to 1400 per 1000 gal of groundwater extracted to 585,000, corresponding to 225 per 1000 gal of groundwater extracted. The capital costs... 

The use of sohd acid catalysts has several advantages over acidic solutions. On the one hand, using sohd materials reduces the risk of toxicity and corrosion, and on the other it improves the separation and the regeneration of the catalyst. They could feasibly be used in reactors of pump-and-treat systems and in permeable reactive barriers (PRBs). Table 3 provides an overview of the ma-... 

If the soil is polluted, another cleanup method may be required to remediate contaminated ground. Thus, the coupled electrokinetic permeable reactive barrier system (EK-PRB) system should be effective to clean up polluted groundwater by the PRB system as well as to remediate contaminated ground by the EK system. The following section describes the investigations on a feasible field application of the EK remediation coupled with the PRB system to remediate contaminated ground of low-permeability soils. 

In view of the advantages of the EK process (capable of removing contaminants from low-permeable media) and PRBs (ability to adsorb/reduce/degrade contaminants in the barrier), this chapter describes the EK process coupled with PRBs (EK-PRB) that has been developing (see Fig. 23.1). The problems of clogging in the PRB system due to the precipitation of ferric oxide or ferric hydroxide would be overcome by EK operation. Since the remediation period of the EK process is much shorter than that of PRB for groundwater remediation, the long-term performance of the loss of barrier reactivity in the EK-PRB process would not be a serious problem if there is sufficient Fe° in the barrier. Reactive heavy metals and... 

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