| Abstract |
Emissions of metals and organics from a series of four wastewater sludge incinerators were determined. Three multiple hearth units and one fluidized bed combustor were tested. Emissions were controlled with a combination of venturi and/or tray impingement scrubbers. One site incorporated an afterburner as well. Flue gas testing was conducted at the inlet and outlet to the air pollution control devices at two of the plants. Feed sludge was also extensively tested for moisture, metals, and organics, as well as overall feed rate and heating value. Testing operating conditions were categorized as short-term versus long term (transients, start-up, interruptions, etc.). The metals found in greatest concentrations in the sludge were lead, chromium, and nickel; and the highest metal emission rates were of lead and cadmium. Organics were tested for in terms of volatile species (B.P. 30C - 100C) and semi-volatiles species. For the volatile species, toluene had the highest concentrations in the sludge and acrylonitrile, benzene, toluene, chloroform, and vinyl chloride had the highest emission rates. Few of the target semi-volatile compounds were detected in either the sludge feed or at the stack. |
