Combined Acidification and Solar Drying of Pig Slurries for Nutrient Recovery and Controlled Atmospheric Emissions
Author
Prenafeta-Boldύ, Francesc X.
Noguerol, Joan
Soler, Joan
Illa, Josep
Publication date
2021-01-25ISSN
2073-4395
Abstract
The solar drying of pig slurries was tested in a pilot-scale greenhouse (10 m2 footprint), operated with forced ventilation under low and high solar irradiation in Mediterranean conditions. Gaseous emissions were prevented through slurry acidification and by the biofiltration of exhaust gases. Air relative humidity and temperature in and out the greenhouse, as well as the weight of a slurry sample, were monitored online to command the ventilation regime. Daily average drying rate values ranged from 0.3 to 2.8 kg m−2 d−1 and displayed a direct dependency with solar radiation until the pig slurry lost a 60% of its initial weight, with a solar energy efficiency of about 26%. Upon further drying, the water content from pig slurries stabilized at around 10%. Mass balances between the initial slurry and dried product were closed for total solids and organic matter, but the recovery of nutrients ranged from 69% to 81%, apparently because of precipitation and incrustation phenomena. The NPK composition of the final product was 4.3–2.5–3.8 and fulfilled current regulations for solid organic fertilizers. Operational costs of the drying process and fertilizing quality parameters were also discussed.
Document Type
Article
Document version
Published version
Language
English
Subject (CDU)
504 - Threats to the environment
Pages
12
Publisher
MDPI
Is part of
Agronomy
Citation
Prenafeta-Boldú, Francesc X., Belén Fernández, Marc Viñas, Joan Noguerol, Joan Soler, and Josep Illa. 2021. "Combined Acidification And Solar Drying Of Pig Slurries For Nutrient Recovery And Controlled Atmospheric Emissions". Agronomy 11 (2): 222. doi:10.3390/agronomy11020222.
Program
Sostenibilitat en Biosistemes
This item appears in the following Collection(s)
- ARTICLES CIENTÍFICS [2503]
The following license files are associated with this item:
Except where otherwise noted, this item's license is described as http://creativecommons.org/licenses/by/4.0/