Biochar Produced from Anaerobically Digested Fiber Reduces Phosphorus in Dairy Lagoons
- Jason D. Streubel *a,
- Harold P. Collinsb,
- Julie M. Tararac and
- Rebecca L. Cochranb
- a Convoy of Hope, 330 S. Patterson, Springfield, MO 65803
b USDA–ARS, Vegetable and Forage Research Unit, 24106 N. Bunn Rd., Prosser, WA 99350
c USDA–ARS, Horticultural Crops Research Unit, 24106 N. Bunn Rd., Prosser, WA 99350. Mention of trade names or commercial products in this article is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the U.S. Department of Agriculture. Assigned to Associate Editor Katherine Knowlton
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−1 P from the ADE, and 4 g L−1 ADF was captured as a coating on the biochar. There was an increase of total (1.9 g kg−1), Olsen (763 mg kg−1), and water-extractable P (914 mg kg−1) 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 31P 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.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
Copyright © 2012. . Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.