UTILIZATION OF GASIFICATION BIOCHAR FOR THE REDUCTION OF GREENHOUSE GASES AND AMMONIA EMISSIONS IN SWINE SLURRY STORAGES

Circular economy, sustainability in agriculture, reuse of by-products, reduction of waste, reduction of emissions, improvement of plant efficiency and exploitation of resources are among the main objectives contained in the 2030 United Nations Agenda. Since this virtuosity often also brings a significant reduction of costs, the market increasingly requires this “circular approach”. This study aims to reduce greenhouse gas emissions (methane and nitrous oxide) and ammonia from swine slurry when it is stored in tanks or lagoons. The study investigates the reduction of emissions through the application of gasification biochar, a low-density and high-porosity material, able to interact, physically and biologically, with thepig slurry. To evaluate the best methodology, three different theseswere investigated: a 5 cm biochar floating layer on the surface of the slurry; filter biochar cartridge crossed by the slurry; nitrifying-denitrifying system in which biochar is used as substrate for micro-bacterial growing colonies. A control thesis, without biochar, was also installed. Three experimental campaigns of two months each (winter, spring, and summer measurements campaigns) were carried out during which greenhouse gases, ammonia and odor emissions were monitored every ten days. Biochar, recognized to date as soil improver, once applied to the pig slurry lagoon can bedistributed on fields. This study investigates, in fact, also the improved agronomic biochar characteristics obtained thanks to the micro and macro nutrients adsorbed or bound to the grains after the biochar slurry contact. This work evaluates the environmental sustainability of the biochar application in slurry treatments. Moreover, reduction of emissions from the storages, increase of stable carbon and nutrient elements in the soil after the application of slurry-biochar mix and economic feasibility of the treatments are investigated, to be able to carefully evaluate the scaling up and the industrial application of these technology. The results identify the biochar as atreatment that can be used for the reduction of greenhouse gases and ammonia emission from swine manure storage lagoon. In particular, the best results were obtained with biochar used as a substrate for microbial colonies. The results showed, in fact, that the nitrifying/denitrifying treatment is the more promising application, compared to the other two tested methodologies. From the chemical analysis performed on the biochar, of all three theses, it was confirmed that the biochar can be used as a soil improver and can be applied to the soil as nitrogen and phosphorus rich amendment.