The distribution and movement of polyphosphate and associated cations in sludges from NDEBPR plants in different configurations at pilot scale

A gradual change in the mode and location of intracellular storage of polyphosphate was observed during a long-term pilot-scale evaluation of operating efficiency of a number of EBPR process configurations used for model calibration. The location of intracellular polyphosphate, (defined by the extraction procedure), was seen to change from a long chain form to a lower molecular weight or short chain form under the influence of nitrate return to the anaerobic zone, which was related to a number of factors including influent character (TKN/COD, influent RBCOD) and process configuration, however during trials with high TKN/COD (greater than or equal to 0.13) the storage of polyphosphate was observed to exist predominately in the short chain form. The behaviour of EBPR biomass in a sequencing batch reactor demonstrated mobilisation and storage of polyphosphate from only the low MW form. (C) 1998 IAWQ. Publsihed by Elsevier Science Ltd