The aim of this work is to study the biodecomposition process of household organic waste (HOW) in closed "BIOLAR" reactors and to characterize the compost obtained using conventional methods and spectroscopic techniques. With this in mind, two biodecomposters were built, inside which ROD was placed daily, packed with sawdust, in a volume of 17% and 52% respectively. To monitor the process and characterize the compound obtained, temperature, elemental analysis, pH, ash content, CTC and UV/Vis, IR and C13 NMR spectroscopic analyses were carried out.