|TAKATA, VIRGINIA - Universidad De La República|
|DEL PINO, A - Universidad De La República|
Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 11/28/2018
Publication Date: 11/28/2018
Citation: Takata, V.H., Szogi, A.A., Del Pino, A. 2018. Extraction and recovery of phosphorus from dairy manure using the Quick Wash Process (Extraccion y Recuperacion de Fosforo del Estiercol Vacuno Utilizando el Proceso Quick Wash).1st National Congress Sustainable Management of Residues, November 28-29, 2018, Montevideo, Uruguay. 1-7.
Technical Abstract: The large volumes of residues generated by agro-industries and agriculture are a problem at the time of their management for final disposal. Land disposal is the common practice for using residues as amendment for soil improvement. This practice brings an increase of soil phosphorus (P) because of the nutrient imbalance of the amendments versus the incapacity of crops to absorb large loads of nutrients. As a result, P accumulates in soils, prone to be lost by soil erosion and run-off and generating contamination in waterways. In order to reduce nutrient pollution, it is necessary to adopt technologies that minimize the problems generated by the disposal of residues. The Quick Wash technique, which consists of acid washing animal manure, has been used for the extraction of P from swine manure, generating two products: one rich in P (recovered P) and another low in P but rich in carbon and nitrogen (washed manure solids). Both products supply plant nutrients in a more balanced fashion. The research objective was to evaluate the Quick Wash technique with dairy manure. Including a no treatment control, two treatments (T1 and T2) compared acidification in two instances: before and after separation of coarse animal manure solids. The acid rate was 25 milimoles of sulfuric acid per litter of slurry. From the acid extract, P was recovered by adding 2.2 grams per liter of calcium hydroxide and anionic polyacrylamide (PAM). The P recovery in the control, T1, and T2 treatments were 35, 44, and 58% of the initial total P content of the fresh manure, respectively. An X-ray diffraction analysis revealed that the precipitates in the control, T1, and T2 had amorphous calcium phosphate containing 4, 7 and 8% as P pentoxide, respectively. It was concluded that these precipitates can be used as a fertilizer source. The N:P relationship of the manure washed solids were 6.7, 8.8, and 11.3 in the control, T1 and T2. This study includes the C and N mineralization rates determined after a 70-day incubation of washed solids and fresh dairy manure applied on surface or incorporated to soil.