A new screw press and Bioset system for Little Blue Valley in Independence, Missouri
The Little Blue Valley Sewer District (LBVSD) wastewater treatment plant treats an average daily flow of 25 MGD. The solids processing portion of the treatment process consists of centrifuges that feed a fluid bed incinerator. During routine maintenance, the plant was forced to haul liquid or dewatered sludge to the landfill when either the centrifuges or incinerator were out of service. Hauling sludge resulted in a considerable increase in operation costs.
LBVSD evaluated various dewatering technologies and sludge disposal options. Schwing Bioset’s 1203X screw press technology was selected not only because of the reliability and low maintenance inherent in the design, but it’s also the only screw press on the market that could handle the plants full solids load with a single unit and fit in the available footprint. Lime stabilization was also evaluated to have the lowest capital expenditure compared to other treatment processes such as digestion. The Bioset system was selected because of the technologies proven track record of reliable treatment, without the operational challenges traditionally associated with lime stabilization.
The new screw press from Schwing Bioset is dewatering 4,700 dry lbs/hr of sludge to a minimum dryness of 24%. This sludge is either fed into the plant’s fluid bed incinerator or to the new Class B Bioset process. During incinerator down time the Bioset process treats the facilities dewatered WAS and primary sludge to Class B. LBVSD has brokered off-take agreements with local farmers and nurseries to receive the sludge at a fraction of the cost of land filling.