Disposal of olive oil mill wastes in evaporation ponds: Effects on soil propertiesDisposal of olive oil mill wastes in evaporation ponds: Effects on soil properties Peer-Reviewed Journal Publication Δημοσίευση σε Περιοδικό με Κριτές 2015-11-022010enThe most common practice followed in the Med countries for the management of olive oil mill wastes (OMW) involves disposal in evaporation ponds or direct disposal on soil. So far there is lack of reliable information regarding the long-term effects of OMW application on soils. This study assesses the effects of OMW disposal in evaporation ponds on underlying soil properties in the wider disposal site as well as the impacts of untreated OMW application on agricultural soils. In case of active disposal sites, the carbonate content in most soils was decreased, whereas soil EC, as well as Cl−, SO42−, PO43−, NH4+ and particularly K+ concentrations were substantially increased. Soil pH was only marginally affected. Phenol, total N, available P and PO43− concentrations were considerably higher in the upper soil layers in areas adjacent to the ponds. Available B as well as DTPA extractable Cu, Mn, Zn and Fe increased substantially. Most surface soil parameters exhibited increased values at the inactive site 6 years after mill closure and cease of OMW disposal activities but differences were diminished in deeper layers. It is therefore concluded that long-term uncontrolled disposal of raw OMW on soils may affect soil properties and subsequently enhance the risk for groundwater contamination.Δημοσίευση σε επιστημονικό περιοδικό http://creativecommons.org/licenses/by/4.0/Journal of Hazardous Materials1-3182 144–155 Kavvadias Vasileios Καββαδιας Βασιλειος Doula M.K. Komnitsas Konstantinos Κομνιτσας Κωνσταντινος Liakopoulou N. Elsevier Olive mill wastes Soil properties Groundwater contamination Risk