BioTrol soil washing system

The big difference in application from the in situ flushing method is that this ex situ method can apply to soils with lower permeability, because soil is excavated and can be sufficiently washed. The following presents two ex situ soil washing processes for organic contaminants the BioGenesis soil cleaning process and the BioTrol soil washing system. 

FIGURE 18.16 BioTrol soil washing system process diagram. 

The BioTrol soil washing system is a patented, water-based volume reduction process used to treat excavated soil. It separates slightly contaminated, coarse, washed soil particles from heavily contaminated fine soil particles. The process operates on the premise that (1) contaminants tend to be concentrated in the fine size fraction of soil (sUt, clay, and soil organic matter) and (2) contaminants associated with the coarse soil fraction (sand and gravel) are primarily surficial. The BioTrol soil washing system can be used to treat soils contaminated with petroleum hydrocarbons, pesticides, polychlorinated biphenyls (PCBs), various industrial chemicals, and metals. 

BioTrol soil washing system costs for the MacGilhs and Gibbs Superfund site in New Brighton, Minnesota, were examined on both an integrated and a unit process basis. Costs for the demonstration study were extrapolated to full-scale treatment of the wood preserving site. The extrapolation included both operating costs and capital costs amortized over an assumed 10-year equipment life span. Costs were estimated in 1991 dollars. 

If all three technologies [soil washing (SW), slurry bioreactor (SBR), and BioTrol aqueous treatment system (BATS)] are used, the estimated cost of a commercial-scale soil washing system is 168/ton ( 185/metric ton). Incineration of woody material removed during washing accounts for 76% of the cost (D110690, p. 43). 

Soil washing system (water-based volume reduction) at MacGillis Gibbs Superfund site in Minnesota (Cheremisinoff, 1989) PAHs, PCBs, and PCP BioTrol, Inc., Minnesota... 

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