Primary sludge thickening project
This project will add primary sludge and scum thickening to the existing biosolids treatment process to remove excess water from the digester feed sludge and scum, thereby reducing the hydraulic and heating load on the digestion process and increasing its capacity. Thickening the primary solids prior to digestion will remove approximately 50 percent of the water and will double the SRT (Solids Retention Time) in the digestion process. Increasing the SRT will increase VS (Volatile Solids) destruction, increase biogas production, reduce pathogens, and produce a more stabilized biosolids product from the digesters, thus reducing the odor generating potential in downstream dewatering, hauling, and land application processes.
The Primary Sludge Thickening Building improvements include construction of a new 15,000 square foot building. The ground floor level of the new building will house sludge and scum thickening equipment, polymer storage and feed equipment room, electrical room, control room, and restroom. The below grade basement area will house the thickened sludge blending/equalization tank and digester feed pumps, drainage tank and pump station, process piping, and biogas treatment and compression equipment. This project also includes a new bioscrubber for treating odors generated by the solids thickening process. Provisions have been made in the design of the facility to add additional processing equipment in the future as solids loading increases and treatment requirements change.