Full Scale Treatment of Slaughter House and Meat Packing Waste at Jennie-O Turkey Store, Barron, Wisconsin

Jennie-O Turkey Store owns and operates a 0.057 m3/sec (1.3 MGD) treatment plant for treating wastewater from the slaughter of 26,000 turkeys per day. In 2000, Jennie-O Turkey Store was required by the Wisconsin Department of Natural Resources (WDNR) to remove phosphorous below 1 mg/l. The existing lagoon system with seepage cell was not removing phosphorous cost effectively and odors were a continuing issue. To improve the plant's waste treatment process, an activated sludge system was proposed to replace the lagoon system.After screening and pumping at the existing slaughter facility, wastewater flows to an equalization basin, and then receives primary treatment through dissolved air flotation (DAF), using ferric sulfate and anionic polymer as flocculants. The DAF effluent is then further treated in an Orbal oxidation ditch for complete nitrification, phosphorus removed with ferric sulfate, alkalinity controlled with magnesium hydroxide, clarified and UV disinfected. The waste activated sludge is DAF thickened in a second DAF tank using a cationic polymer and joins the primary DAF float sludge in sludge storage. Sludge in the storage tanks is mixed 3-times per year and liquid hauled to land application. During the year, decant from the sludge holding tanks is pumped to the waste activated sludge DAF unit for solids removal and the underflow goes to the oxidation ditch. The new activated sludge system came on-line in June 2002.This paper presents the results of a comprehensive and innovative evaluation to overcome a persistent filamentous bulking problem in an industrial waste treatment facility. Specifically, it will reveal how a multi-ring oxidation ditch was modified, with minor construction changes, to provide selector benefits in treating highly soluble BOD wastewater. Actual data from startup through three years of operation will show the impact of a selector on activated sludge settling and control of filament O21N. The paper disproves, at least in this specific case, the theory that a selector effect occurs in the outer ring of such ditches due to alternating aerobic and anoxic conditions. In actuality, introducing the wastewater to the outer ring of this ditch helped propagate the growth of filament O21N, likely due to rapid dispersion of the soluble waste throughout the ring volume. In contrast, introducing the wastewater to the inner ring of the ditch and reversing the flow through the ditch has shown to significantly control the growth of filament O21N and has provided a simple, easy to operate, and very cost-effective solution to the filamentous bulking problems.