VALORIZATION OF OLIVICULTURE RESIDUES TO PRODUCE BIOCHARS FOR THE REMOVAL OF NAPROXEN FROM WATER

Adsorption is a treatment process based on accumulation of the adsorbate (pollutant) on the adsorbent surface that has been successful used for the optimization of wastewater treatment plant effluents cleaning. This work will present the main experimental results for the removal of naproxen from water by adsorption using activated carbon obtained from olive stones. Four types of activated carbon material were prepared from olive stones. The batch method was applied to experimentally measure the equilibrium adsorption isotherms. The most significant adsorption parameters were optimized, such as the solution pH, mass of the adsorbent, contact time and temperature. The physicochemical characterization of the pyrolyzed material shows a considerable superficial area of 608 m2/g when compared with other natural biomass-based materials. A removal efficiency of 100% was obtained for 24 h and a pH=4.5. The Langmuir model was used to better describe the adsorption behavior for adsorbent with better removal performance with the highest maximum adsorption capacity value of 35.2 mg naproxen/g adsorbent. The kinetics of the adsorption is well described by a pseudo-second order model. Obtained results in this work clearly show that olive stones, usually a residue from the Portuguese and Mediterranean oliviculture, can be exploited as a promising and lowcost biomass source on the production of adsorbent materials with considerable potential to remove micropollutants, such as the naproxen, from water.