Determination of bicarbonate and total volatile acid concentration in anaerobic digesters using a simple titration

ABSTRACT: A simple, alkalimetric method is described that can be used to determine bicarbonate and total volatile fatty acid concentrations in anaerobic digesters by a two‐stage sequential titration. The new method was evaluated by standard solutions of volatile fatty acids and bicarbonate over a pH 5.5 to 7.65 range. It was also used to determine the total volatile fatty acid and bicarbonate concentrations in effluent samples from five laboratory anaerobic digesters treating different types of waste. The average recovery of volatile fatty acids and bicarbonate by the new method from standard solutions was found to be 96%. The total volatile fatty acid concentration measured by the new method from the digester ceffluent samples coincided well with those measured by a chromatographer.