The application of photocatalysis in the treatment of organic micropollutants in wastewater is an interesting alternative and is the object of a great interest over the last years by many researchers. The stage of adsorption of the micropollutant on the photocatalyst, mainly the titanium oxide anatase form, is a determining stage in the process of photodegradation. We present an experimental study of the adsorption of phenol, chosen as the model pollutant, on a photocatalyst, titanium oxide anatase (Degussa P25). The measure of the quantity of phenol adsorbed was made by UV spectroscopy. The equilibrium of adsorption was reached after 1 h; the kinetics of adsorption were slow and obeyed the Lagergrein model. The adsorption was chimisorption in a monolayer and obeyed the Langmuir model. The survey also showed that there was an advantage to operate at great velocity of agitation and a natural pH. The agitation by ultrasonic drives to a light increase of phenol quantity adsorbed (5%) because this mode of agitation reduces the phenomenon of agglomeration of titanium oxide particles and therefore increases the interfacial area of the catalyst.