POLLUTING CHARACTERISTICS AND LIME PRECIPITATION OF OLIVE-MILL WASTE-WATER

Olive mill wastewaters originating from olive extraction units are the most polluted wastewaters of the food industry which present a toxici ty towards plants as well as certain impacts to the hydro-flora. Pollu tion abatement for olive mill wastewater is difficult, because they ar e seasonal, highly concentrated, very polluting, and the processing un its are small, and can not withstand the cost of a depollution. This p aper mainly concentrates on the polluting characteristics and lime pre cipitation as a minimal pre-treatment procedure for the removal of org anic matter content. The sludge produced of the addition of 0.5-3% CaO reduces the concentration of suspended solids in the ''vegetation wat ers'' by 27.6% whereas 77.1% of the oil and grease are distributed in the precipitate fraction. The COD as well as the toxic load in terms o f phenolic compounds are not strongly affected by the addition of CaO.