Two aerobic digesters were constructed and put in service in June, 1992 for stabilization and reduction of waste activated sludge from our wastewater treatment facility. This process includes tankage, aeration, piping, neutralization and mixing equipment. In the process waste activated sludge is aerated for a period of 20 days, during which time the microorganisms consume their own protoplasm to obtain energy for cell maintenance. The majority of cell tissue is oxidized to carbon dioxide, water and ammonia. The ammonia is oxidized to nitrate as the digestion proceeds.
Odors associated with our waste activated sludge have virtually been eliminated. In addition, the quantity of sludge being disposed has been reduced by over 40% or 1.5 million pounds a year.
Details of Reductions
Additional Information :
Since less sludge needs to be disposed, there is a cost savings of approximately $350,000 per year. The payback period for this project is about 6 years.