Induction of phosphorus removal in an enhanced biological phosphorus removal bacterial population

Volatile fatty acids (VFAs) resulting from prefermentation of influent glucose were used to cultivate a bacterial population capable of enhanced biological phosphorus removal (EBPR) in two identical anaerobic/aerobic sequencing batch reactors (SBRs). An identical SBR receiving starch, which did not readily preferment, established only marginal EBPR. The Starch SBR population did not respond in batch tests to any of the substrates studied. In batch tests for the glucose SBR populations the two to five carbon VFAs, except propionic acid, induced greater inorganic phosphate (P-i) removal. Succinic acid also improved removals. Branched VFAs were superior to their linear isomers. Isovaleric acid improved P-i removal the most consistently, and at lower molar concentrations than any other VFA. The C-2 and C-5 alcohols did not have a significant effect on P-i removal, and neither did formate or methanol. The C-3 and C-4 alcohols did result in relatively small but consistent improvements in removals. Glucose, as well as amino acid rich synthetic wastewater, were both extremely detrimental to P-i removal. Fructose and starch did not have the same detrimental effect as glucose. (C) 1997 Elsevier Science Ltd