The olive oil mill wastewater presents serious environmental threats. In this study, adsorption heat pumps utilizing zeolite coatings were proposed for olive oil mills as a helping tool for the treatment of wastewater, as well as for providing a cooling effect, which may especially be useful to prevent thermal deterioration of the olive oil. The performance of a heat pump using two adsorbers operating with waste heat was determined for different operating conditions. It was established that a sufficiently high amount of olive oil wastewater might be treated in such a system when a suitable source of waste heat is used for heating the adsorbers of the heat pump. Copyright (C) 2007 John Wiley & Sons, Ltd.