DYNAMISKA PILOTSKALEFÖRSÖK MED OLIKA FOSFORBELASTNINGAR I EN BIOLOGISK FOSFORAVSKILJNINGSPROCESS / Dynamical Pilot-scale Experiments with Different Phosphorus Loadings in a Biological Phosphorus Removal Process
Experiments with three different phosphorus loadings have been conducted in pilot-scale. During an experimental period of 24 hour with normal loading the effluent concentration of PO4-P was stabile around 0.1 mg/1. The results show that even if the phosphorus loading is increased up to four times or if 60 % of a 24 h load is chockloaded to the process, the effluent concentrations are not affected. The oxygen concentration from the aerobic step has to be between 2-3 mg O2/1. This to ensure that enough oxygen is present for the uptake and on the other hand prevents release of phosphate in the clarifier. 2-3 mg O2/l in the aerobic effluent does not adversly affect the anaerobic step by oxygen transport in the recycled sludge. The F/M ratio affects the phosphate release in the anaerobic reactor to a limit; after this does the phosphate release not increase with increasing F/M ratio. Max phosphate releases were during the normal phosphorus load, 5.5 g P/kg VSS*h and during increased load 8 g P/kg VSS*h. The maximum phosphate uptake rate in the pilot plant was measured to 9 g P/kg VSS*h.