COMPARATIVE STUDY OF ORGANIC MATTER DEGRADATION OF COMPOSTED SLUDGE AND SLUDGE LANDFILLED </br> ETUDE COMPARATIVE DE LA DEGRADATION DE LA MATIERE ORGANIQUE DES BOUES COMPOSTEES ET BOUES MISES EN DECHARGE
SLIMANE LAHSAINI(1), LEILA IDRISSI(1), SALAH SOUABI(1*), LOUBNA EL FELS(2), ANAS AGUELMOUS(1), MOHAMED HAFIDI(2)
1. Université Hassan II, Faculté des Sciences et Techniques, BP 146, 20650, Mohammedia, Maroc 2. Université Cadi Ayyad, Faculté des Sciences Semlalia, Bd Prince My Abdellah, B.P. 2390, 40000, Marrakech, Maroc *Corresponding author: salah.souabi@gmail.com
Abstract
The results of the biotransformation of organic matter for three trials A (500 kg sludge + 400 kg turf + 100 kg of straw), B (1000 kg sludge composted alone), and C (1000 kg sludge landfilled) after six months show a good degradation rate for trial A, compared to B, and C. C/N ratio decrease from 30 to 12 for mixture A, from 32 to 19 for B, and from 32 to 24 for C. An important decomposition rate, about 74 %, for mixture A has been reached after six months. The final compost for mixture A exhibited a high concentration (151.7 g·kg-1) of humic substance and a low concentration of heavy metal contents, compared to the AFNOR standard (NF U 44-041). The efficiency of the composting is confirmed by the germination index (GI), which exceeds 90 % for the trial A. However, phytotoxicity for trials B and C remains less important (GI does not exceed 40 %). The results of trial A will open the way for the agricultural use of sludge.