Main composting methods and techniques for aerobic or anaerobic decomposition

in ecoTrain3 months ago

Before describing some composting methods and techniques, we will first talk about a factor that I overlooked in the previous post and that is undoubtedly important for the quality of the compost, I am referring to the pH, this factor influences the process due to its action on microorganisms, they have different pH requirements, however the ideal range is between 6.5 and 8.0.

▶ Credits: Wasteadvantagemag. – [Image of Public Domain]

▶ Credits: Sunspoturbanfarm. – [Image of Public Domain]

▶ Having already mentioned the importance of pH, let us remember that compost is obtained in a natural way by aerobic decomposition (with oxygen) of organic waste such as vegetable and animal remains, excrements and slurry (highly polluting liquid part that oozes from all types of animal manures).

Fundamentally, this decomposition occurs through the massive reproduction of aerobic thermophilic bacteria that are naturally present everywhere (later, the fermentation is continued by other species of bacteria, fungi and actinomycetes). Normally, the aim is to avoid (as far as possible) the putrefaction of organic waste (due to excess water, which prevents aeration and oxygenation, creating foul-smelling anaerobic biological conditions), although certain industrial composting processes use putrefaction by anaerobic bacteria.

Now, among the main composting techniques we have the composter method, which are composts made with MSW (municipal solid waste), it is important to mention that there are several composting sub-techniques, which are adjusted to different needs; the choice of one technique or another depends, among other things, on the amount and type of material to be processed, available investment and availability of land, operational complexity and the final product to be obtained.

The different systems are determined by the aeration mechanisms used in the process, generally grouped into: passive aeration, forced aeration, and aeration by turning the material.

▶ Credits: Newenglandcompost. – [Image of Public Domain]

Another technique is the composting in static piles, these piles are formed in a large metal box (minimum 1 m3, maximum 1.5 m3) with a lid, placing a thick layer (approximately 6 cm) of sawdust or soil and left without movement, all organic waste is poured there and covered with another layer of soil, to maintain moisture is sprayed with a little water that is essential and sprinkled with lime to prevent odors. It ends up being ventilated naturally by a process of natural thermal convection. In this procedure there is no temperature, the processes are the natural ones at room temperature. In the next publication I will continue to expand on other techniques of equal or greater importance.

NOTE: Reference material.

I invite you to stay tuned and read my next contribution