Use of carbonate and alkali to eliminate Escherichia coli from dairy cattle manure

A procedure to eliminate Escherichia coli in dairy cattle manure was develo ped. E. coli persisted in fresh manure and farm storage tanks, and viable c ounts ranged from 10(5) to 10(8)/g. If the feces to urine ratio of fresh ma nure was decreased from 2.2 to 1, E. coli did not persist for greater than or equal to 10 days (<10 viable cells/g), and it appeared that the urine wa s killing E. coli. Fecal urease contamination produced CO2, and 16% was tra pped as carbonate. When urine pH was decreased, antimicrobial effect was lo st, even if the pH was readjusted to 8.5. When E. coli K-12 and O157:H7 wer e treated with Na2CO3 (100 mM, pH 8.5, 24 h), viable cells were not detecte d. The E. coli count of manure (feces to urine ratio of 2.2:1) was decrease d by Na2CO3 addition (8 g/kg), but pH sometimes declined and carbonate was lost. When NaOH was included (2 g/kg), Na2CO3 additions could be decreased (4 g/kg), and treatment time was 5 days. Treatment cost could be <$10 year( -1) (dairy cow)(-1). Water dilution (3-fold) did not diminish the effective ness of the carbonate/alkali treatment, and viability was <10 cells/g.