The issue of organic recycling is particularly relevant in the field of waste management if we consider that the wet fraction represents 40% of the total municipal solid waste sorted in many countries. But what does the treatment of organic waste involve. In some countries we have the possibility of treating the organic fraction through the composting process, which can take place at an industrial level thanks to the plants located throughout the national territory, or at home, if you have a garden or an outdoor area open.

The industrial composting system of organic waste   is a natural process of aerobic degradation, which takes place in the presence of oxygen, which activates the biological transformation of the organic substance into compost. The process replicates, in faster times, what happens in the humification of the undergrowth, that is the production of humus, a precious substance for the natural fertilization of the soil. In composting, the control of conditions (humidity, oxygenation, temperature, etc.) improves and accelerates the biological process.

Even in composting, as in nature, the protagonists are the microorganisms present in the soil, which activate a series of biochemical reactions and release water, carbon dioxide and mineral salts; at the same time the reactions stabilize the organic substance, which is transformed into fertile soil, which is the compost. The microorganisms involved are essentially:

Bacteria that act as fast decomposers; they are able to use the most easily degradable substances and, in doing so, generate heat. Bacteria capable of degrading more complex substances, such as proteins, cellulose, lignin; they are mainly responsible for the characteristic earthy smell that emanates from mature compost.

Fungi capable of degrading complex molecules, such as waxes and lignin; turning them into simpler products, they generate new nourishment for the bacteria.

The industrial composting plants receive the organic urban waste, which in Italy is composed of the collection of wet waste, mowing from public green areas and residual material from agro-industrial processing. In the case of home composting, kitchen and garden waste can be recycled, but with some extra attention because not all foods are suitable.

Fruit and vegetable waste, tea and coffee grounds, egg shells, garden and vegetable waste and biodegradable materials such as uncoated paper, cardboard, sawdust and shavings from untreated wood can be used.

Instead, leftover food of animal origin and cooked foods that attract insects and animals should be used sparingly. Furthermore, some plants have leaves that degrade over a long time, such as magnolia, beech, chestnut and pine needles and must be added in small quantities.

Absolutely to be avoided are waste of synthetic origin or contaminated with toxic substances , such as cigarette ash, animal litter, fabrics, coated paper (magazines), diseased plants or plants treated with insecticides.