Background A large national food processing company operates a strawberry fruit dicing facility in central California. This facility only operates during the strawberry growing and harvesting season (April through July). In 1994, a $1.5 million wastewater pretreatment facility was installed in the plant to bring it into compliance with the city regulatory standards. The pretreatment did lower BOD and TSS well below permit levels. In 1997, the plant management decided to evaluate ACCELL as an agent to reduce sludge volume and disposal costs, as well as control mal odors emanating from the digester. 

Year 1 Treatment 1996 was used as the baseline data point and the plant was operating at an effluent flow rate of 250,000 gallons per day. During the first packing season, plant management decided to apply ACCELL to the aerobic digester. They felt that the effects and cost of the product could be measured more precisely by limiting the use of the product to one identifiable are. A dose ranging evaluation took place during the first few weeks and it was determined that the application of 10 ppm of ACCELL would be the most cost effective. While the initial objective of the trial was the reduce sludge volume and control odors, plant management also monitored the aeration electric power consumption. 

Results: Sludge volume was reduced by 50% and electric power costs were reduced by 32% during the first year trial. Occasional aerobic digester odor problems were also eliminated.

Year 2 Treatment Since the processing plant had experience such positive results during the first packing season trial, management decided to evaluate ACCELL effectiveness when utilized during the whole treatment process. The product was applied at the front end of the treatment system in the aeration tanks at a rate of 10 ppm of effluent processed. 

Results: Sludge volume was further reduced showing a 60% decrease from the 1996 baseline date. Electric power costs were also further reduced showing a 49% decrease rom the 1996 baseline data.

During the third year, the plant continued to successfully use the product and the effluent rate had increased to 400,,000 gallons per day.