Review of Two Mechanical Separation Technologies for the Sustainable Management of Agricultural Phosphorus in Nutrient-Vulnerable Zones

This work reviews two mechanical separation technologies (screw press and decanting centrifuge) which could be used in the dairy, beef, pig anaerobic digestion sectors nutrient-vulnerable zones order to improve sustainability of manure digestate management by decreasing agricultural phosphorus loss reducing environmental impact on water quality. Capital operating costs, efficiency throughput, processing separated fractions, including transport impacts biosecurity solids for export, were considered. Of reviewed, screw is a more cost-effective option (5-fold cheaper per tonne feedstock) when lower amounts export off farm are acceptable. For farms those with digesters managing larger volumes manure/digestate, possible. However if higher levels removal required, use centrifugation viable option. Centralised facilities also make centrifuge technology act as hubs local within distance that makes it economical manure/treated to/from processor (the maximum raw approximately 70 km 84 km, respectively). Both integrated into systems provide sustainable approach its associated Screw reduce phosphorous bodies 34% from 30 93%, respectively.