Biovalorisation of Two-Phase Olive Mill Waste by Composting Process

The two -phase olive mill waste resulting from the extraction of olive oil a major problem for the olive industry because of their polluting power which originates from a high loading of phenolic compounds. The treatment of Two-phase olive mill (TPOM) was performed by the composting process with horse manure and spent coffee ground for 24 weeks. During composting, the intense microbial activity has translated by an increase in temperature (61.78C -67.98 C) during a week. The final composts show an increase in pH, electrical conductivity, total nitrogen, and a decrease in organic carbon. These final composts have a C/N ratio close to 10, and abundance of the agrochemical element (P, K, Na, Ca). The humic substrates of the composts were evaluated in order to monitor the composting progress. The polyphenol reduction was about 93.06 %. The phytotoxicity, determined by the effect of water-soluble extracts on the germination of cress seeds, after 24 weeks of composting