EVALUATION OF LABORATORY BATCH TESTS FOR ENHANCED BIOLOGICAL PHOSPHORUS REMOVAL
Phosphorus release batch tests can be used for evaluation of an activated sludge process with enhanced biological phosphorus removal (EBPR or bio-P). The test method is described and different aspects of the result evaluation are discussed. The concentration of dissolved phosphorus in a sample from the activated sludge is followed during an anaerobic period within a batch reactor or a beaker. The release of phosphorus is used to
estimate the activity of phosphate accumulating organisms (PAOs). In addition to the phosphorus analyses, VFA (volatile fatty acids) can be analysed in order to estimate the fraction of glycogen accumulating organisms (GAOs) competing with PAOs for available VFA. Potassium and magnesium can be analysed to evaluate if chemical precipitation affect the test results. Chemical precipitation, temperature, pH and presence of nitrate
or oxygen are example of factors that can influence results from the test.