Studies were undertaken to determine the adsorption behavior of α-cypermethrin [R)-α-cyano-3-phenoxybenzyl(1S)-cis-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate, and (S)-α-cyano-3-phenoxybenzyl (1R)-cis-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate] in solutions on granules of cork and activated carbon (GAC). The adsorption studies were carriedout using a batch equilibrium technique. A gas chromatograph with an electron capture detector (GC-ECD) was used to analyzeα-cypermethrin after solid phase extraction with C18 disks. Physical properties including real density, pore volume, surface areaand pore diameter of cork were evaluated by mercury porosimetry. Characterization of cork particles showed variations therebyindicating the highly heterogeneous structure of the material. The average surface area of cork particles was lower than that of GAC.Kinetics adsorption studies allowed the determination of the equilibrium time—24 hours for both cork (1–2 mm and 3–4 mm) andGAC. For the studied α-cypermethrin concentration range, GAC revealed to be a better sorbent. However, adsorption parametersfor equilibrium concentrations, obtained through the Langmuir and Freundlich models, showed that granulated cork 1–2 mm havethe maximum amount of adsorbed α-cypermethrin (qm) (303 μg/g); followed by GAC (186 μg/g) and cork 3-4 mm (136 μg/g). Thestandard deviation (SD) values, demonstrate that Freundlich model better describes the α-cypermethrin adsorption phenomena onGAC, while α-cypermethrin adsorption on cork (1-2 mm and 3-4 mm) is better described by the Langmuir. In view of the adsorptionresults obtained in this study it appears that granulated cork may be a better and a cheaper alternative to GAC for removingα-cypermethrin from water.
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