No abstract

The problems created in managing olive mill wastewater (OMW) have been extensively investigated during the last few years. In most cases, dehydration of olive mill wastes is a first step before developing further applications. The subject of this study was to determine the drying behavior of OMW solid fraction (OMWS). Drying (moisture vs time) and shrinkage (image vs time) data were obtained on slabs of OMWS in an air dryer operated at 60-80 C. The effective diffusivity was determined using (a) the simplified solution of Fick's second law and (b) the method of slopes of the drying curve, taking into account the effect of moisture content on diffusivity and sample shrinkage. The combined effect of moisture content and temperature on effective diffusivity was expressed by an empirical model. In addition, each moisture loss and shrinkage curve was fit to 10 simplified drying models. The dependence of the best descriptive model constants on drying temperature was expressed by an appropriate type of model.