Method for treating waste, in particular household refuse, and unit for implementing same

A process for treating waste containing organic matter mixed with undesirable products, the process comprising:

• the waste is subjected to a first sorting by screening,
• a fraction of the waste passing through the screening is subjected to a prefermentation treatment in a rotating tube with a feed end and an extraction end,
• and material leaving the rotating tube is subjected to mixing in a mixing hopper, then to a methanization treatment in a digester,
• wherein:
• the organic matter is separated from the undesirable products in the material leaving the rotating tube before entering the mixing hopper,
• the digester is horizontal, mechanically stirred, and a fraction of digestate leaving the digester is recirculated directly after leaving the digester at least to the mixing hopper, a recirculation ratio being high enough to ensure complete mixing, wherein the recirculated digestate enters the mixing hopper with a solid particle content of between 30% to 40%.