In the present work, the concentration and recovery of high-added value phenolic compounds from two-phase olive mill wastewater (OMW) and the simultaneous effluent treatment by a ‘green process’ based on resins adsorption/ion exchange was studied. Olive oil is produced by a technological procedure based on physical operations, without use of chemicals. This industry is concerned to make the whole process environmentally friendly, which includes the treatment of the wastewater produced in the mills. The proposed weak-based IE process was statistically optimized and modelled. Results showed the resin performance was optimal at the raw effluent pH and ambient temperature conditions, which means no acidification or basification, nor cooling or heating would be needed. This would imply important savings for the scale-up of the process in real mills. The examined resin ensured minimum 72.4% phenols adsorption after 2 h contact time. The effluent could be partially discharged on suitable terrains or disposed to biological treatments, avoiding phytotoxicity or inhibition due to the phenolic content. The obtention of this concentrated pool of added-value antioxidant compounds for food, cosmetics, pharmaceutical and biotechnological industrial sectors could help counter-balance the economic feasibility of the reclamation process.