© by PSP Volume 21 – No 1. 2012 Fresenius Environmental Bulletin 84 STUDIES ON REMOVAL OF NAPROXEN SODIUM BY ADSORPTION ONTO ACF IN BATCH AND COLUMN Çiğdem Sarıcı-Özdemir * , Yunus Önal, Selim Erdoğan, Canan Akmil-Başar Inonu Universty, Faculty of Engineering, Department of Chemical Engineering, 44280, Malatya, Turkey ABSTRACT In this study, activated carbon fibers were prepared from textile waste by chemical activation with ZnCl 2 (and coded IPZN1, IPZN2, and IPZN3). After preparation they were characterized by analyses using the BET surface area, FT-IR, and XRD methods. The ability of IPZN1, to re- move naproxen sodium from effluent solutions by adsorp- tion was studied. Results were analyzed by the Langmuir, Freundlich, Dubinin-Radushkevich (D-R), Temkin, Frum- kin, Halsey and Henderson equations using linearized cor- relation coefficients at 298 K. The value of Q 0 was deter- mined as 294.11 mg.g –1 and the ∆G value of -21.46 kJ.mol -1 for adsorption of naproxen sodium. The fixed-bed adsorption system was used for study of the adsorption of naproxen sodium onto IPZN1. Experiments were conducted to study the effect of flow rate of naproxen sodium. Decreasing the flow rate was found to enhance capacity. The breakthrough data obtained for naproxen sodium was adequately de- scribed by the Thomas and Yoon-Nelson adsorption mod- els. This study revealed that ACF is suitable for use as an effective adsorbent for the adsorption of naproxen sodium. KEYWORDS: Activated carbon; Naproxen sodium; Isotherm; Column adsorption 1. INTRODUCTION Pharmaceuticals are emerging as a class of environ- mental contaminants that are extensively and increasingly being used in human medicine. They vary greatly in their chemical structures and are subjected to variations in their concentrations and loads. Naproxen is a member of the arylacetic acid group of non-steroidal anti-inflammatory drugs of which naproxen sodium is one. Naproxen so- dium leaves the human organism unmetabolized via urine or sludge, and can affect water quality as it has the poten- tial to impact on drinking water supplies and health of the ecosystem [1-5]. * Corresponding author Activated carbon is a microporous adsorbent that can be produced from a various carbonaceous materials, includ- ing wood, coal, lignin, coconut shells, and sugar [6-9]. Its high porosity makes activated carbons the most widely used material for adsorption of toxic substances. Acti- vated carbon is also manufactured by carbonization and activation of fabrics made of several polymeric materials such as nylon, phenolic resin, cellulose etc. [10]. This cate- gory of activated carbon is known as activated carbon fiber (ACF) and is manufactured in two presentations: as cloth and as felt. ACF’s pore structure is composed mainly of micropores. Fixed-bed adsorption columns are widely used in wa- ter treatment. This technique has proved effective in re- moving organic contaminants. The major part of the ad- sorption process at any time takes place in a relatively narrow adsorption column. As the solution continues to flow, the mass transfer zero which is S-shaped, moves down the column. The total capacity of the bed tower, if the entire bed comes to equilibrium with the feed, can be shown to be proportional to the area between the curve and a line at C/C 0 = 1. The total shaded area represents the total- or stoichiometric capacity of the bed as follows [11- 13]. ∫ ∞ − = 0 0 ). 1 ( dt C C t t (1) where t t is the time equivalent to the total capacity. C o and C (mg.L –1 ) are inlet- and outlet concentrations, re- spectively, of the contaminant solutions. The usable capac- ity of the bed up to the break point time t b is the cross- hatched area, ∫ − = b t u dt C C t 0 0 ). 1 ( (2) where t u is the time equivalent to the usable capacity. The value of t u is usually very close to that of t b . Of the total bed length of H T , cm, H B is the length of bed used up to the break point; T t u B H t t H . = (3)