Kinetics of nitrogen removal in a MBR nutrient removal activated sludge system

It is found that, at the same ML concentration, the specific ammonia utilization rates (nitrification rate) for the conventional BNR system are approximately 1.8 times higher than those found in the parallel MBR–BNR system, probably due to different selective pressures. In contrast, no differences in specific denitrification rates were found. As the ML concentration in the MBR–BNR batch tests is increased, the specific nitrification rate and maximum specific growth rate of the nitrifiers (µmax,n) decrease, The results obtained confirm that the introduction of membranes into BNR systems may cause associated changes in the kinetics of BNR. Further experimental work is currently being undertaken to determine and to quantify anaerobic P release, anoxic P release/uptake and aerobic P uptake kinetics and any ML concentration effects. The results will be examined in a future paper.