Several environmental companies consider phenols compounds to be very dangerous pollutants because they are highly toxic and non-biodegradable, notably their high toxicity in water. For this reason, several processes have been studied by researchers to understand the mechanisms of elimination of phenolic compounds. Adsorption remains the best technique due to its characteristics, in fact, it is non-destructive and simple to use as well as have more other advantages, such as practicality and efficiency and low cost, Therefore, these methods need to be widely developed on an industrial scale to remove phenol derivatives and achieve wastewater quality in accordance with standards. On the other hand, the development of these adsorption methods is highly dependent on new research on materials from abundant natural resources, namely apatites or biomaterials.

The olive mill waste water (OMWW) are effluents issued from the extraction of olive oil, these effluents are cloudylooking liquids with a reddish-brown color, their pH varies from 4 to 5. They are very rich in polyphenols, which causes many environmental problems, such as water pollution, Currently, on an industrial scale, there is no reliable, efficient, and less expensive technique for OMWW treatment. OMWW are evaporated in watertight basins or discharged into watercourses. Several techniques have been studied to treat these industrial effluents. The objective of this work was to compare these studies to formulate the recommendations that can be adopted for an effective and cheaper treatment of these effluents which constitute a major environmental problem for water resources. Indeed, it can be concluded that it is very difficult to treat OMWW by conventional methods due to its non-biodegradability and high cost of others methods like distillation and oxidation. In the end, it was concluded that for a better OMWW treatment, it is necessary to start firstly by the adsorption of phenolic compounds which are responsible for the nonbiodegradability of OMWW while using cheaper adsorbents namely clays, bio-adsorbents or apatites, then dilute the OMWW with domestic wastewater. The dilution of OMWW by urban wastewater leads to good mineralization of organic matter by enriching the medium with microorganisms, which facilitates the elimination of the organic load and then we use the usual techniques as a plant filter or active sludge for mixture treatment.