Bio-P Removal from High Phosphorus Wastewaters: Pilot Testing Confirms Applicability of the Process

The performance of biological phosphorus removal from combined wastewaters of municipal and pig farm origin containing up to 100 mg/l initial phosphorus was investigated on a PhoStrip semi-industrial size pilot plant. Objective of the experimentation was to assess the applicability of Bio-P removal to high strength liquors in association with biological nitrification/denitrification. The experimental results indicate that high combined phosphorus and nitrogen removal efficiencies can be obtained, while still operating at practicable process conditions. The operation of the pilot plant demonstrated that the dual phosphorous “sink” - with phosphorus-enriched waste activated sludge and with chemically precipitated HAP - is a key factor to consistently achieve low effluent phosphorus concentrations in activated sludge systems operating at high phosphorus loading.