The process in the composting plant begins with the control of waste and the mechanical separation of foreign and non-biodegradable contaminants, such as plastic and metal.
The selected material is then shredded and mixed using special machinery. The preparation of the mixture is essential to obtain a mass with porosity such as to guarantee the penetration of air. Furthermore, if on the one hand it is necessary to provide material that is easily degradable by the first microorganisms organic waste, on the other hand the material rich in lignin and cellulose cuttings and twigs it is essential for the subsequent humification phase. After preparation, the material is arranged in heaps on large surfaces, equipped at the bottom with grids for the recovery of the leachate and with ventilation openings. The leachate that originates from the various processing phases is collected and reused on the heaps at the beginning of the process, in case it is necessary to increase the humidity of the mass. Throughout the process, mechanical arms periodically mix the mass to ensure the right oxygenation.
During the bio-oxidation the biological processes of natural commercial composting Australia are triggered and the material loses water and volume.The initial phase lasts from one to six weeks, depending on the conditions and the quantities of materials to be composted. During this phase, the microorganisms in action are aerobic bacteria that live at temperatures of 18-45 ° C and begin the decomposition of the most easily assimilated organic substance, such as carbohydrates, lipids and proteins. To do this, the bacteria consume oxygen and release water, carbon dioxide (CO2) and heat.
The heat, which causes the temperature to rise up to 55-60 ° C, causes the microbial load to drop, naturally bringing the process to the next so-called thermophilic phase , in which different microorganisms, more resistant to temperature, operate. In this phase, the new bacteria, capable of living at temperatures of 50-70 ° C, fix carbon dioxide in energy compounds over a period of time that can last 40-50 days.
Decomposition continues with slower processes at the expense of complex molecules such as cellulose and lignin. In these conditions of low humidity, fungi operate, the process of which progressively causes the temperature to drop below 45 ° C. In this stage the humification, or the production of humus, takes place in a minimum period of 50 days. Once fully ripe, the compost can be subjected to a refining and final screening treatment. This allows eliminating any foreign bodies and decomposed woody parts, which are reused in mixing at the beginning of the process. Before being placed on the market, thecompost produced is analyzed to verify compliance with legal requirements.