Assessment of recycling perspectives for olive mill solid waste in Palestine

Abstract

Olive mill solid waste (OMSW) or olive cake, locally known as “Jift”, is the major solid waste generated by the olive oil industry in Palestine. It is also known as “olive husk” or “olive pomace” in some other olive oil producing countries. The organic rich by-product is under utilized in Palestine. After simple drying process and without any treatment, farmers in rural areas use only limited amounts of the waste, as a burning material to produce heat, as a fertilizer, or as animal fodder. The remaining quantity is disposed off either in uncontrolled landfill dump sites or discharged into open channels causing environmental problems. OMSW is mainly made of olive stones and pulp for which the heating value makes it attractive to be used as a source of energy. When used as a source of energy, OMSW has the potential to replace to some extent the use of fossil fuel as a burning material and therefore, to reduce the associated emissions of pollutant gases into the atmosphere. OMSW can also be utilized, efficiently, as animal feed, fertilizer, and in manufacturing. The desk study conducted over four months during 2004, aims at perspectives assessment of OMSW recycling in Palestine with special emphasis on characteristics, quantities, present status of reuse and disposal methods. In addition, sustainable utilization techniques of OMSW as a source of energy are presented and discussed with regard to having the potential to be technically adequate, environmentally sound, and economically feasible in Palestine. The quantity of OMSW varies according to the annual yield and the manufacturing process. The characteristics of OMSW, however, vary according to the origin of olives and the type of extraction process used. Utilization techniques of OMSW which have the potential to be feasible in Palestine should be considered. Co-composting and anaerobic digestion of OMSW to produce energy have the potential to be feasible and can be recommended for Palestine. However, the feasibility of the other techniques depends very much on funds availability. Pilot scale studies on such techniques in Palestine should be encouraged and supported. Hence, the farmers, the energy generation industries, and the environment can benefit if such a waste is fully utilized on a sustainable approach.