Combined PCDD/F destruction and particulate control in a baghouse: experience with a catalytic filter system at a medical waste incineration plant.

Phoenix Services, Inc., owns and operates the Baltimore Regional Medical Waste Incinerator in Baltimore, MD. New regulations for dioxins and furans imposed a limit that was considerably below historical emission levels. To determine a method to comply with the new dioxin/furan regulations, Phoenix Services performed trials with powdered activated carbon (PAC). Although the results with carbon were acceptable, Phoenix Services decided to replace their woven fiberglass filter bags with catalytic filters that simultaneously destroy dioxins and furans and collect particulate matter (PM). The catalytic filter system offered several advantages to Phoenix Services, including destruction of dioxins and furans instead of adsorption on carbon. The catalytic filters also offered a passive solution that did not require new carbon injection equipment. In January 2000, a campaign to measure dioxins/furans and PM was undertaken. The measurements allowed the catalytic filter system to be evaluated. Some of the key findings of this investigation are The dioxin/furan emission was less than 0.1 ng toxicity equivalents (TEQ)/Nm3 at 11% O2. This concentration is approximately 2 orders of magnitude less than historical averages and it is well below the new regulatory limits, for both existing and new sources of this type; the amount of dioxin/furans destroyed by the catalytic filters was approximately 1.73 ng TEQ/Nm3 at 11% O2; and the particulate emission was 12-17 times less than the regulatory limit.