PEER-REVIEWED ARTICLE bioresources.com Olivella et al. (2011). “Quercus cerris cork sorbent,” BioResources 6(3), 3363-3375. 3363 SORPTION PERFORMANCE OF QUERCUS CERRIS CORK WITH POLYCYCLIC AROMATIC HYDROCARBONS AND TOXICITY TESTING M. Àngels Olivella, a, * Patrícia Jové, b Ali Şen, c Helena Pereira, c Isabel Villaescusa, d and Núria Fiol d Quercus cerris is an important oak species extended in large areas of Eastern Europe and Minor Asia that has a thick bark which is not utilized at all. The sorption performance of cork from Quercus cerris bark with four polycyclic aromatic hydrocarbons (PAHs) (acenaphthene, fluorene, phenanthrene, and anthracene) was investigated. Quercus cerris cork was characterized for elemental analysis, acidic groups, and summative chemical composition, and the results were compared with Quercus suber cork. A Microtox® test was carried out to test for the release of any toxic compounds into the solution. All isotherms fit the Freundlich model and displayed linear n values. Quercus cerris exhibited a high efficiency for sorption of PAHs for the studied concentrations (5 to 50 μg/L) with 80- 96% removal, while the desorption isotherms showed a very low release of the adsorbed PAHs (<2%). In relation to Quercus suber cork, K F values of Quercus cerris cork are about three times lower. The quantity of Quercus cerris cork required to reduce water pollution by PAHs was estimated to be less than twice the quantity of other adsorbents such as aspen wood and leonardite. Toxicity tests indicated that non-toxic compounds were released into the solution by the Quercus cerris and Quercus suber cork samples. Overall the results indicate the potential use of Quercus cerris cork and of Quercus suber cork as effective and economical biosorbents for the treatment of PAH-contaminated waters. Keywords: Quercus cerris; Quercus suber; Biosorbent; Sorption-desorption; Polycyclic aromatic hydrocarbons (PAHs); Toxicity Contact information: (a) Department of Chemistry, University of Girona, Campus Montilivi s/n, 17071 Girona, Spain; (b) Catalan Cork Institute, C/Miquel Vincke Meyer, 13, 17200, Palafrugell, Girona, Spain; (c) Centro de Estudos Florestais, Instituto Superior de Agronomia, Universidade Técnica de Lisboa, Tapada da Ajuda, 1349-017, Lisbon, Portugal; (d) Department of Chemical Engineering, Escola Politècnica Superior, University of Girona, Avda Lluis Santaló , s/n 17071, Girona, Spain. *Corresponding author: angels.olivella@udg.edu INTRODUCTION Polycyclic aromatic hydrocarbons (PAHs) are contaminants that originate from the combustion of fossil fuels. Highly suspected to be probable carcinogens, they are transported by the atmosphere into surface waters (Olivella 2006). Because of their persistence and low solubility they may be accumulated in the food chain (García-Falcón and Simal-Gándara 2005; García-Falcón et al. 2005; Rey-Salgueiro et al. 2007; Rey- Salgueiro et al. 2009a,b). Although activated carbon is probably one of the most effective conventional methods for the removal of PAHs from water (Derbyshire et al. 2001;