Ensuring daily life with safe drinking water is an essential issue of human society [1]. Among the pollutants identified in water, toxic substances are of particular concern, even at very high dilutions, showing maximum resistance to biological degradation. Phenolic pollutants, which occupy the 11th position in the list of 126 priority pollutants listed in the United States Environmental Protection Agency refers to this category of contaminants [2]. In the present research, the adsorption parameters of o-nitrophenol were studied on two samples of autochthonous carbonic adsorbents, obtained from apricot stones (AC-C) and from apple wood (AC-MR). The advantages of the new adsorbent materials were evaluated in relation to the results determined for the retention of o-nitrophenol on two samples of commercial activated carbons, AG-5 and BAU. The time required to reach the adsorption equilibrium of o-nitrophenol on the investigated activated carbons was determined from the adsorption kinetic curves, measured at three initial concentrations (50, 100 and 200 mg/l) in the interval of time between 15 -360 minutes. The obtained experimental results show that, at the initial stage the immobilization of the phenolic pollutant is quite a fast process. Thus, in the first 30 min, the autochthonous activated carbons retain approx. 76.5% (AC-MR) and 57.2% (AC-C) from the total amount of adsorbate and on the commercial activated carbons they immobilize between 51% (BAU) and 20% (AG-5). The nature of the adsorbents also significantly influences the contact/stirring time required to reach the equilibrium of the adsorption process, which oscillates between 120 min - 180 min for local carbonic adsorbents (AC-MR, AC-C) and 240 min - 300 min for commercial samples (BAU, AG-5). The adsorption isotherms of o-nitrophenol on the investigated activated carbons were determined at different temperatures (25○C, 35○C and 45○C). The results show that, with the increase of the temperature values by 20○C, the retention of o-nitrophenol decreases by approx. 5-8%, which indicates that the adsorption process studied is an exothermic one. The research carried out indicates the advantage of autochthonous activated carbons over commercial ones in parameters such as the speed and duration of the immobilization process, as well as the retention rate of the investigated adsorbate