Alkalinity measurement: part 3 - a 5 pH point titration method to determine the carbonate and SCFA weak acid/bases in aqueous solution containing also known concentrations of other weak acid /bases

The theoretical basis for a 5 pH point acid titration method is described that allowed the determination of carbonate alkalinity, total carbonate species concentration and total short-chain fatty acid concentration in anaerobic digester liquids containing known concentrations of other weak acid/bases. The contributions of these other weak acid/bases to total alkalinity were subtracted to allow the calculation of carbonate and short-chain fatty acid. The method provided an estimate of any systematic pH measurement error, provided that the carbonate subsystem dominated over the short-chain fatty acid subsystem. (see also preceeding abstracts).