title: Biochar produced from anaerobically digested fiber reduces phosphorus in dairy lagoons.
abstract: This study evaluated the use of biochar produced from anaerobic digester dairy fiber (ADF) to sequester phosphorus (P) from dairy lagoons. The ADF was collected from a plugged flow digester, air-dried to <8% water content, and pelletized. Biochar was produced by slow pyrolysis in a barrel retort. The potential of biochar to reduce P in the anaerobic digester effluent (ADE) was assessed in small-scale filter systems through which the effluent was circulated. Biochar sequestered an average of 381 mg L P from the ADE, and 4 g L ADF was captured as a coating on the biochar. There was an increase of total (1.9 g kg), Olsen (763 mg kg), and water-extractable P (914 mg kg) bound to the biochar after 15 d of filtration. This accounted for a recovery of 32% of the P in the ADE. The recovered P on the biochar was analyzed using P nuclear magnetic resonance for P speciation, which confirmed the recovery of inorganic orthophosphate after liquid extraction of the biochar and the presence of inextractable Ca-P in the solid state. The inorganic phosphate was sequestered on the biochar through physical and weak chemical bonding. Results indicate that biochar could be a beneficial component to P reduction in the dairy system.
authors: Convoy of Hope, Springfield, MO, USA. jstreubel@convoyofhope.org
authors: Jason D
authors: JD
authors: Streubel
authors: Harold P
authors: HP
authors: Collins
authors: Julie M
authors: JM
authors: Tarara
authors: Rebecca L
authors: RL
authors: Cochran
mesh_terms: D000693:Anaerobiosis; D000818:Animals; D002417:Cattle; D002606:Charcoal / Q000737:chemistry*; D005374:Filtration / Q000379:methods; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy; D009584:Nitrogen / Q000737:chemistry; D010758:Phosphorus / Q000737:chemistry*; D013455:Sulfur / Q000737:chemistry; D013997:Time Factors; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D014874:Water Pollutants, Chemical; C540010:biochar; D002606:Charcoal; D010758:Phosphorus; D013455:Sulfur; D009584:Nitrogen