title: Carbon, nitrogen, and phosphorus distribution in particle size-fractionated separated pig and cattle slurry.
abstract: Solid liquid separation of animal slurry is a method to reduce the excess nutrient loads from intensive livestock production. Five different separation technologies (sedimentation, centrifugation, pressurized filtration, polymer flocculation and drainage, and iron chloride addition + polymer flocculation and drainage) were applied to pig and cattle slurry in a laboratory study. Separation efficiencies of mass, dry matter (DM), N, and P were measured. Particle size fractionation of the solid fractions was performed by subjecting them to wet fractionation and C, organic N (N(org)), and P contents were subsequently measured. Chemical pretreatment with polymer before gravity drainage separated DM, total N, and P from raw pig and cattle slurry with the highest efficiencies. Sedimentation and centrifugation separated P from pig and cattle slurries with higher simple separation efficiencies (0.77 and 0.70, respectively) compared with pressurized filtration (0.15 and 0.37). Pressurized filtration transferred the lowest masses (14 and 18%) to the solid fractions. Solid fractions from pig slurry generally contained higher concentrations of P and C compared with cattle slurry solid fractions. The majority of C in solid fractions was present in particles > 25 microm, whereas N and P were present in larger proportions in particles < 25 microm. Chemical pretreatment increased the capture of smaller N(org)- and P-rich particles into larger particles between 25 and 1000 microm.
authors.affiliation: Dep. of Agric. and Ecology, Faculty of Life Sci., Univ. of Copenhagen, Denmark. karinj@life.ku.dk
authors.forename: Karin
authors.initials: K
authors.lastname: Peters
authors.forename: Maibritt
authors.initials: M
authors.lastname: Hjorth
authors.forename: Lars Stoumann
authors.initials: LS
authors.lastname: Jensen
authors.forename: Jakob
authors.initials: J
authors.lastname: Magid
mesh_terms: D000818:Animals; D002244:Carbon / Q000737:chemistry*; D002417:Cattle; D009584:Nitrogen / Q000737:chemistry*; D010316:Particle Size; D010758:Phosphorus / Q000737:chemistry*; D013552:Swine; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D010758:Phosphorus; D002244:Carbon; D009584:Nitrogen