AW Produced in the Mediterranean Region: Qualitative and Quantitative Characteristics
Olive Oil Mill Wastewaters (OMW)
Generated in huge quantities over a short period every year (November - April), OMW represent a significant environmental problem in Mediterranean countries. One tone of olives produces approximately 0.8 tones of OMW which are characterized as acidic (pH 4-5), with an average chemical oxygen demand (COD) and biochemical oxygen demand (BOD) content of 120 and 60 g/L, respectively, high concentration of suspended solids (7-15 g/L) and phenolic compounds up to 24 g/L. Their disposal may cause adverse effects on soils, surface- and groundwaters. A number of technologies such as physical, physico-chemical, biological and thermal have been developed for OMW treatment but when used individually suffer from drawbacks e.g., low efficiency or high cost. However, combined or advanced alternative methods show encouraging results (Ben Sassi et al., 2006; Niaounakis and Halvadakis, 2006; Mekki et al., 2007; Khoufi et al., 2008; Komnitsas et al., 2011; Camarsa et al., 2010).