ABSTRACT
This research focused on the treatment of wastewater from the Excel Corporation beef slaughterhouse located at Schuyler, Nebraska. Research was conducted using the Anaerobic Sequencing Batch Reactor (ASBR) process developed at Iowa State University by Dr. Richard R. Dague and coworkers (U.S. Patent No. 5,189,079).
This research was intended to show the feasibility for application of the wastewater to the ASBR system. Research was conducted using two ASBR units over a 13-month period. The first unit was seeded with granular sludge obtained from the Heileman brewery in Lacrosse, Wisconsin and the second unit was seeded with flocculent sludge from the municipal wastewater treatment plant in Ames, Iowa. The units were operated at 30°C to simulate the wastewater temperature at the Excel facility.
This research has shown that the ASBR system is effective in the treatment of wastewater from the Schuyler Excel Corporation slaughterhouse. The system remained effective in terms of removals and operational parameters over a range of organic and solids loadings. Periods of sharp increase in organic loading (shock loading) due to the sampling and feeding procedure were also evaluated and the results shows the system performed well. System performance depended significantly on hydraulic retention time (HRT), with lower HRTs resulting in lower removal efficiencies. Consistent results can be attained at a 30-hour HRT. At this loading, the granular achieved average removals of over 70% based on BOD5 and 50% based on COD.
Granular and flocculent seed were both effective in treatment of the wastewater. Granular seed was more easily held in the reactor, resulting in better startup and higher removals early in the study. MLVSS concentrations in the granular reactor ranged from approximately 10 to 16 g/L under steady state conditions. After establishment, flocculent seed performed as well as granular seed at lower HRTs with more consistent removals even though it operated at much lower biomass levels. MLVSS concentrations in the flocculent reactor ranged from approximately 2 to 4 g/L under steady state conditions.
