By Marcio L.B. da Silva
Embrapa Swine and Poultry – Brazil is the fourth larger swine producer and exporter of the world. This position was achieved with significant changes in the production systems over the last 30 years, from a small, subsistence model to larger confined animal feeding operations. However, confined swine production has been a major public concern in Brazil due to the large amount of waste generated in these operations and its potential impact on soil, air, and water quality, urging the necessity of proper manure treatment and disposal.
Composting of swine manure is an alternative that has been promoted in Brazil to manage swine manure. This practice allows water evaporation and transforms liquid manure into a solid material of high organic value as biofertilizer that is easy to handle and transport to nearby fertilizer demanding lands. The project is evaluating greenhouse emissions during composting and proposing innovative technologies to accelerate biological metabolism towards composting and emissions reduction.
The use of liquid manure as fertilizer is also being evaluated. Its benefits as a biofertilizer suggest that it is a promising compound compared to expensive mineral fertilizers. Besides testing biofertilizer concentrations in several crops the project is also evaluating new equipment’s to better distribute and release the biofertilizer in soils in ways to optimize nitrogen fixation and minimize emissions to atmosphere.
Anaerobic digestion of manure produces biogas methane that can be utilized as a sole source of fuel or to generate electricity. The biodgestors technologies are being studied in ways to efficiently promote biogas volumes as well as its quality. There is an increasing interest to develop biogas energy centers in Brazil, particularly for electricity generation. Biogas filtration methods are also being investigated.
Swine waste effluent is usually partially treated using biodgestors which is quite efficient to remove the organic carbon but nutrients such as nitrogen and phosphorus. These nutrients can ultimately cause eutrophication of water bodies. Lagoons are usually installed downstream of biodgestors to minimize nutrient load. Nonetheless, land availability may not always be suitable. The use of SISTRATES (swine wastewater effluent treatment system) can be quite effective to remove such nutrients producing high quality water that can be reused. During the treatment process phosphorus can be removed and utilized as a valuable source of fertilizer.
The use of microalgae as a feedstock to produce biofuels, food and pharmaceutics is regaining credibility and attention worldwide. Microalgae can growth using nutrients from swine waste effluent thus treating the effluent while simultaneously generating valuable biomass. Engineered photobioreactors or open lagoons are being studied as a means to treat effluent from agribusiness and evaluate the potential of the biomass as a source of bioenergy and animal nutrition.
Click here to download of the presentation of “Animal waste as a Source of Animal By-Products and Bioenergy. at “2012 Global Green Hub Korea (GGHK)”. Seoul, South Korea, 2012