Low Cost Treatment and Disposal of Olive Mill Wastewater

During the extraction of oil from olives, large amounts of potable water are used, solid waste, and olive mill wastewater (OMW) are generated. OMW is phytotoxic, has antibacterial effects, and high pollution potentials. Azraq bentonite (AB), reddish volcanic tuff (RVT), lime (CaO), aluminum sulfate (alum), ferric chloride, and sodium carbonate were used to remove turbidity (NTU) and non-specific organic compounds (COD) from OMW. The results showed that RVT, ferric chloride, and sodium carbonate are not efficient in removing turbidity (NTU) and COD from OMW. The removal of NTU and COD using alum was 95% and 65% respectively. Alum is not recommended, since it is expensive to use. The removal of NTU and COD using lime were 99% and 69% respectively. AB showed 96% removal of NTU and 37.5% removal of COD. Lime and AB are inexpensive and locally available materials. The treated OMW can not be used in agriculture because of their high dissolved solids content; therefore, natural evaporation in shallow ponds, after lime or AB treatment, might be an acceptable solution.