- The stabilization of the waste: in the phase of thermophilic bio-oxidation (see below), the microorganisms, in the presence of oxygen, oxidise the organic matter through the mineralization of the more easily fermentable fraction.
- The sanitation of the waste: aerobic decomposition frees a substantial amount of energy as heat; in the mass of material, in controlled fermentation, temperatures (55-70°C) destroy the pathogens, stabilizing the product from the biological point of view.
ACCORDING TO THE MATRIX USED IN COMPOSTING, THREE TYPES OF PROCESS CAN BE DISTINGUISHED:
- Green compost (lignocellulosic waste);
- Quality composting (various selected organic matrices);
- Composting of waste as RU unselected at origin.
MORE IN DETAILS, THE COMPOSTABLE MATERIALS ARE:
- plant residues (straw, pruning, mowing …)
- residues of agricultural production (stillage husks, stalks, collars …)
- sub-products from wood processing
- food wastes originated from domestic or agro-industrial productions
- organic wastes originated from municipal solid waste (MSW)
- animal wastes (manure and slurry)
- sewage sludge
The quality compost obtained from the separated organic waste collection by an industrial process may be conveniently exploited in agriculture taking advantage of a natural fertilizer and avoiding the use of chemical fertilizers to full field. The floriculture, amateur and professional, makes convenient use of this compost. The marketing of the improver composts is regulated by Legislative Decree of 29 April 2010, n. 75. The compost, not having the quality standard set by Legislative Decree no. 75/2010, can not be traded and is commonly used to cover the landfill of waste and agricultural reclamation. The anaerobic digestion also allows to obtain the biogas usable as fuel.