The PROZOO project has achieved the expected results for the valorisation of pig waste in order to obtain by-products and energy. The SSICA condenser prototype transformed the digestate derived from a biogas plant and separated it into a condensate, ammonia fraction (80%), and a concentrate (20%). The reverse osmosis of the condensate resulted in an ammonia fertilizer (10-12%) and a permeate for discharge into surface water bodies. The condensate was subjected to pyrolysis in the prototype at SITEIA, at times mixed with dry vegetable biomass, obtaining the biochar. The analysis of the biochar obtained shows a good granulometry, basic pH and low salt content. Phytotoxicity tests show stimulating effects on the growth of barley and lettuce and no negative effects. The agronomic tests were carried out on barley (cv Concerto) and industrial tomato (cv FABER). The treatments were carried out with biochar, organic digestate fertilizer and ammonium salts. The effects of the treatments vary according to the crop and strongly depend on the climatic conditions. The final economic analysis considered the impact of the prototypes and the products obtained from the valorisation of the waste. Biochar is the product with the greatest economic benefit, followed by ammonium salts. The results of the project have been disseminated on several occasions in Italy and abroad.
The integrated use of two prototypes for the extraction of effluent from pig:
- Ammonium Salts: fertilizar that remove ammonia component
- Biochar enriched: able to give a nutrient supply and structural benefits to the soil, improving fertility, increasing water retention and increasing adsorption and biodegradation of herbicides with carbon sequestration, enriched with an organic compound, pasteurized, free from harmful substances or volatile, biologically inert.
- Aqueous effluent: having characteristics such as to be suitable for reuse in the same digester or to discharge to surface water reused in the company being a water free from minerals or in the circuits of the two plants.
- Digestate Collection and storage
- Digestate treatment using two prototypes (“evapoconcentratore” carbonizer): the combined use of the two prototypes will enable the conversion of the digestate into a fertilizer, organic fertilizer and nitric acid; in energy from renewable sources with low emission of pollutants
- Use of biochar as a soil enriched agronomic rating.
- Laboratory analysis to characterize the products obtained.