Researchers Turn Olive Mill Wastewater into Green Fuel, Water Source and Fertilizer

Production of olive oil creates a vast stream of wastewater that can foul waterways, reduce soil fertility and damage ecosystems. Hence, a study from Institut de Science des Matériaux de Mulhouse in France developed an environment friendly process that could transform this pollutant into "green" biofuel, bio-fertilizer and safe water for irrigation.

During processing, olives are crushed and mixed with water in mills. The oil is separated out of this mixture, and the olive mill wastewater (OMW) is discarded. The process developed by the Institute first impregnates OMW on raw cypress sawdust (RCS), another common waste product.

Then the mixture is dried and the evaporated water is collected. This water will be safe enough for irrigation. The OMW-sawdust mixture is then subjected to pyrolysis, turning it into combustible gases and charcoal. The researchers then collected and condensed the gas into bio-oil, a biofuel precursor. The charcoal pellets left can now be used as fertilizer.

These results indicate the possibility of converting OMW to green fuels, agricultural water source, and fertilizer.