AN ANALYSIS OF THE FACTORS THAT INFLUENCE BIOLOGICAL PHOSPHORUS REMOVAL (BPR) IN A SEQUENCING BATCH ANAEROBIC AEROBIC REACTOR/

A sequencing batch anaerobic/aerobic reactor was operated in such a ma nner as to simulate typical variations in loading and influent feed co mposition as might be encountered in an urban wastewater treatment pla nt. The impact of these Variations on biological phosphorous removal ( BPR) was assayed using a number of statistical techniques including si mple regression, multiple regression, ANOVA and factorial analysis. Th e results demonstrate the importance of biomass loading on efficiency and relate this to the level of mixed liquor suspended solids retained within the system. The ratio of COD:P in the influent wastewater had no significant impact on removal. Multiple regression analysis of fact ors associated with the release of phosphorous in the anaerobic phase revealed a strong correlation of these factors with subsequent phospho rous uptake efficiency in the aerobic phase. On the basis of the coeff icients derived from the analysis an equation was proposed which showe d a good fit to experimental data on BPR.