Model FW304 Packaged Scrubber Controls Sewage Treatment Odors
Background
The City of Saline, Michigan experienced odor problems emitted from one of their rotating biological contactors (RBC). The project engineer, McNamee, Porter, and Seely of Ann Arbor, Michigan selected Duall Division as the equipment supplier to eliminate these odors.
Results
A Duall model FW304-53-OC was specified. The 5000 cfm unit was constructed of Type II PVC for maximum corrosion resistance. It utilized a random dumped, high efficiency packing and mist eliminator. It was designed for 99% removal of H2S and test results reported efficiencies in excess of 99%. The system also reduced total odor units, measured at the outlet by an independent odor panel, to be less than 20.
The FW-304 system offered several features and advantages including:
- Minimal floor space requirements
- Clear access doors for easy spray nozzle inspection
- Integral centrifugal fan section to eliminate the costs of interconnecting duct and to minimize installation expenses
A NEMA 4X control panel, complete with a pH/ORP analyzer and probes, was used to control the chemical metering pumps. The two chemicals utilized for neutralization and oxidation were sodium hydroxide and sodium hypochlorite.
Present Status
The system was placed into service in March, 1996. All subsequent testing has exceeded design efficiency.