Use of activated carbon obtained from sugarcane straw for PAH adsorption - a comparative study with commercial...

This work evaluates the performance of activated carbon obtained from sugarcane straw (SCAC) as an adsorbent for polyaromatic hydrocarbons (PAHs) present in model wastewater. Two commercial samples of activated carbons with different textural properties were also studied for comparison. The activated carbon prepared from sugarcane straw presents a well-developed porosity with a high surface area, which was comparable to that of one of the commercial samples studied. For all the studied carbons, adsorption followed pseudo-second-order kinetics, and the higher rate constants were found for the SCAC sample for the four PAHs. Sips and Hill isotherms best fitted the adsorption equilibrium data of the PAHs on all activated carbons investigated. The activated carbon obtained from sugarcane straw (SCAC) presented a higher adsorption capacity (2.08 mmol g^-1 for naphthalene, 1.26 mmol g^-1 for fluorene, 1.14 mmol g^-1 for phenanthrene, and 0.98 mmol g^-1 for fluoranthene) when compared to the commercial carbon samples studied in this work as well as for those related in the literature. It confirms that its use of SCAC as an adsorbent for PAHs is a promising application for the valorization of this biomass waste.