Technology and installation for post treating residual urban muds with a view to being used as agricultural fertilizers

Abstract

The invention relates to a process and an installation for post treating residual urban muds in order to obtain a compost to be used as agricultural fertilizer. According to the invention, the process consists in that it is carried out in aeration conditions, by ensuring an amount of oxygen necessary for composting, while monitoring the functional parameters concerning the composting of urban muds in admixture with vegetable waste in a mass ratio ranging from 1 :1 to 4: 1 for 30...60 days wherein a stage of aerobic mesophilic fermentation takes place at a temperature of 25...40 degrees C which consists in increasing the number of bacteria; a thermophilic stage at a temperature of 45...60 degrees C in which the present bacteria, fungi and actinomycetes decompose the cellulose, lignin and other resisting organic substances, the maximum temperature being necessarily to be maintained at least one day in order to ensure the destruction of pathogens and organic contaminants; the last stage being the ageing when temperatures are lowered and some oxidative biological processes are continued and stabilized transforming the degraded organic substrate into humus. The installation claimed by the invention consists of an aeration subassembly (A) which ensures the amount of oxygen necessary in a subassembly (B) for composting and a subassembly (C) for monitoring which measures and records the functional parameters of the process for treating the urban muds.