Bio-derived CuO/olive Cake Nanocomposite for Total Phenols Removal from Olive-mill Wastewater

Acutely high organic-loaded olive mill wastewater (OWW) is produced seasonally from the olive oil processing sectors. In North Cyprus, there is no regulated policy regarding the discharge of olive mill wastewater. Hence, the OWW is routinely discharged into the environment top soil or evaporation ponds, and the solid wastes disposed of without treatment to surrounding lands near the processing mills. This poor management of OWW enhances the risk of polluting the surface water and agricultural soil resources. The environmental threat of the olive mill wastewater is majorly due to the toxicity and low biodegradation of phenolic compounds present in the OWW. This research focused on the feasibility of integrating bio-derived nanoparticles into the surface of waste olives cakes and converting into a high-performance and environmentally nanocomposite adsorbent for removal of total phenol from OWW. An efficient bio-derived CuO/olive cake nanocomposite (BCO-NC) with 266.11 m2/g surface area was prepared using banana peel extract. Under optimised conditions (pH 6 and dosage 2.5g), 80% of total phenols was removed after 180 min in the dark (BCO–NC/dark), but rapidly increased to 100% just after 90 min using BCO–NC/H2O2/sunlight system at pH 10, dosage 1.0g and H2O2 1mM. The removal mechanism is represented by Freundlich isotherm model (R2= 0.996–1.00) and best modelled by pseudo-second-order kinetic. Keywords: Bio-derived nanocomposite; olive mill wastewater, total phenols removal