Effect of chemical treatment on the aromatic carbon content and particle size distribution-based organic matter profile of Olive mill wastewaters

The present experimental work was carried out to examine the physicochemical treatability of a high-strength olive oil mill wastewater (OMW). Firstly, the wastewater was subjected to environmental characterization and particle size distribution-based COD-TOC-UV₂₅₄-UV₂₈₀ analyses. The following treatment schemes were selected for the study: Coagulation-flocculation in the presence of anionic and commercial polymers at varying pH and coagulant/polymer dosages; Fenton treatment at different pH's and Fe(II): H₂O₂ concentrations as well as electrocoagulation using stainless steel electrodes at different electrolyte concentrations and current densities. Results of the study have indicated that none of the investigated physicochemical treatment methods was capable of removing the organic carbon content of the wastewater by more than 30% in terms of COD and 20% in terms of TOC that is at least partially attributable to the high, soluble organic carbon content of the wastewater. Alternative treatment processes and/or combinations have to be explored for effective treatment of OMW effluent.