Newly developed membrane contactor-based N and P recovery process: Pilot-scale field experiments and cost analysis

In this study, a newly developed nitrogen (N) and phosphorus (P) recovery process using membrane contactor termed NPHarvest was tested with different liquid waste streams in large-scale trials. Ammonia captured ammonium sulfate form hydrophobic membrane, while precipitated as sludge alkali precipitation coagulation processes. The were selected to cover the potential for included two mesophilic digester reject waters, landfill leachate, separately collected urine. pilot hydraulic loads range of 12–133 L/h. Nitrogen efficiency reached maximum 92.5% water ammonia flux 481.1 mg/L.h obtained urine stream. A mass transfer coefficient calculated four wastewater approaches, resulting value ranges order 10−3 10−7 m/s. It found that decreased increase initial concentration. varied between 79% 97%. quality evaluated by employing comprehensive tests vegetative cells coliphages, harmful metals, organic micropollutant measurements. These measurements confirmed meets Finnish legislation requirements agricultural use. use diluted acid wash proven be sufficient maintaining surface properties observed insignificant loss hydrophobicity mild development fouling. Finally, competitiveness compared existing processes through detailed cost analysis.