The oil extraction industry generates two by-products, an aqueous effluent, olive mill wastewater (OMWW) and a solid residue, olive mill solid waste (OMSW). OMWW is considered as the major pollutant in the Mediterranean area causing severe environmental threats. The main problem regarding the disposal of OMWW is to find an environmental and economical viable solution. A new valorisation strategy has been carried out which includes the following steps: (a) absorption of OMWW on low-cost renewable absorbents, (b) natural evaporation of the water and (c) energy recovery by combustion of the impregnated absorbents. Sawdust and OMSW were selected as low-cost renewable absorbents. Thermal behaviour of the impregnated samples was studied under inert and oxidative atmosphere from 20 degrees C to 900 degrees C using thermogravimetric analysis (TGA). Kinetic parameters were obtained and compared for the different samples. Gaseous emissions such as CO2, CO and volatile organic compounds (VOC) were measured under oxidative conditions at 500 degrees C, 600 degrees C and at 700 degrees C in a fixed bed reactor. The results indicate that for samples containing the same amount of OMWW, the reaction time of impregnated sawdust is lower compared to impregnated OMSW. Combined treatment of OMMW proposed in this study may be a promising method for the reduction of their environmental impact and for the energetic valorisation of the organic content of OMWW. (c) 2011 Elsevier Ltd. All rights reserved.