Under a contract issued by the Naval Research Laboratory, Retech Services, Inc., designed, constructed and placed into operation at their site a plasma arc hazardous waste treatment system (PAHWTS). It is intended for this system ultimately to be installed on the Norfolk, Virginia, Naval Base (subject to completion of an Environmental Impact Statement and obtaining the necessary permits) and used for the destruction of most of the solid and liquid hazardous waste generated on the base. Operational testing of the system was conducted in October 1999 and included six separate two- or three-hour runs on soil, epoxy paint, latex paint, and methanol mixed with 1,1,1 trichloroethane (TCA) in the ratio of 3.5:1. The feed rates for these materials ranged from 135 to 225 kilograms (300 to 500 pounds) per hour. For the epoxy paint, both liquid and solid materials were fed simultaneously into the primary processing chamber. Stack emissions of CO, NOx, and total hydrocarbons were monitored using continuous emissions monitors and in each case the emissions were below the standard limits covered by the NESHAPS for hazardous waste incinerators. Stack emissions for particulates, metals, dioxins/furans, and HCl were measured in accordance with standard EPA sampling methods. For all runs the particulates and metals were well below the NESHAPS emissions limits. For the soil and epoxy paint, the dioxins/furans and HCl were below the limits; how-ever, for the methanol/TCA and latex paint runs, the emissions for the dioxins/furans and HCl exceeded the emission limits. The destruction and removal efficiency for the TCA exceeded 99.9999%. A potential explanation for the over-limit values for dioxins/furans and HCl is offered.
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