Bioremediation of olive mill pomaces for agricultural purposes.

Existing laws in Italy propose olive mill pomaces (OMP), produced by the two phase system, as a soil amendant. The direct supply of such a raw material poses same problems due to the rainy season and its phytotoxicity. The bioremediation of olive mill pomaces can be an useful and economic technology to overcome those backdowns. Composting has been performed in a forced aerated static pile, mixing OMP with chopped wheat straw. During the process moisture content, pH, EC, organic carbon, nitrogen and phytotoxicity were determined. The thermophilic phase lasted 60 days. The phytotoxicity disappeared at the end of the thermophilic phase. The final product has been examined to determine its physical, chemical and biological characteristics. At the end of the process a C/N = 31 was determined. This high value depends on the presence of the grinded stones, hardly to be microbiologically degraded.