Activated biochars used as adsorbents for dyes removal

Adsorption represents one of the most interesting technique for the removal of pollutants from wastewaters. Activated carbons show the best performances on this kind of processes but their high production costs limit their applications. In this context a big challenge is to find new materials having characteristic similar to those of commercial activated carbons but being environmental friendly and cheaper. In this work the adsorption efficiency of activated biochars produced from pine wood was investigated on the removal of dyes from water. An innovative method for the activation of the biochar using deep eutectic solvents (DES) was tuned and the characteristics of the obtained adsorbent material were compared with those of biochar activated with traditional method and non-activated biochar. The best adsorption capacities were obtained with the DES activated biochar, reaching a value of 480 mg/g for the methylene blue adsorption. Adsorption isotherm and kinetic models were applied to experimental data in order to understand the adsorption mechanism of the process.