Journal of Hazardous Materials B119 (2005) 189–194 Determination of the adsorption capacity of activated carbon made from coffee grounds by chemical activation with ZnCl 2 and H 3 PO 4 A. Namane a,∗ , A. Mekarzia b , K. Benrachedi b , N. Belhaneche-Bensemra a , A. Hellal a a National Polytechnic School, Environmental Department, 10 Avenue Pasteur BP182, El - harrach, Alger 16200, Algeria b Laboratory of Food’s Technology, Faculty of Engineer’s Science, Universityof Boumerdes, BP 70Boumerdes, Algeria Received 17 September 2004; received in revised form 5 December 2004; accepted 6 December 2004 Available online 15 January 2005 Abstract In order to evaluate the adsorptive capacities of granular activated carbon produced from coffee grounds by chemical activation, the adsorption of different phenols and acid and basic dyes, has been carried out. The comparison with a commercial activated carbon has been made. Adsorption isotherms of phenols and dyes (acid and basic) onto produced and commercial granular activated carbons were experimentally determined by batch tests. Both Freundlich [1] and Langmuir [2] models are well suited to fit the adsorption isotherm data. As a result, the coffee grounds based activated carbon may be promising for phenol and dye removal from aqueous streams. © 2004 Elsevier B.V. All rights reserved. Keywords: Adsorption; Coffee grounds; Wastewater treatment; Dyes; Organic pollutants 1. Introduction Water pollution is a very persistent problem, the inten- sive disposal of different toxic substances without control constitutes a real danger. Phenolic compounds are common contaminants in wastewater. They are widely used for com- mercial production of a wide variety of resins [3]. They are harmful at low concentrations, and US Environmental Pro- tection Agency (EPA) call for a maximum phenol content in wastewater of than 1 mg/l [4]. Effluents from dyeing and finishing processes are gener- ally highly coloured with a large amount of suspended or- ganic solids. They are important sources of water pollution because dyes in wastewater undergo chemical as well as bi- ological changes, consume dissolved oxygen, and destroy aquatic life. Therefore, it is necessary to treat textile efflu- ents prior to their discharge into the receiving water. The removal of synthetic dyes (that are carcinogens), has became ∗ Corresponding author. Tel.: +213 21 52 53 03; fax: +213 21 52 29 73. E-mail address: namaneaek@yahoo.fr (A. Namane). an important aspect of textile wastewater treatment and many studies have been conducted on the toxicity of dyes and their impact on the ecosystem, as well as the environmental is- sues associated with the manufacture and subsequent usage of dyes [5]. To remove organic pollutants and/or dyes many treatments have been proposed, such as coagulation, sedimentation, filtration, oxidation (KMnO 4 ,H 2 O 2 , Cl 2 ,O 3 ), adsorption [6–11]. Biological treatment processes are reported to be efficient in the reduction of organic pollutants concentration, but ineffective in removing colour [12,13]. Of these methods, adsorption has been found to be an efficient and economic process, and an effective and widely employed mean of water and wastewater treatment. Despite its prolific use in water and wastewater treatment, commercial activated carbon remains a rather expensive ma- terial. This leads to a search for low cost materials as al- ternative adsorbents. Among these alternatives, agricultural and/or wood wastes such as, sawdust, maize cob, coconut husk fiber’s, fruit kernel, and nut shells appear to be more economically attractive in certain countries because they are abundant [14–16]. 0304-3894/$ – see front matter © 2004 Elsevier B.V. All rights reserved. doi:10.1016/j.jhazmat.2004.12.006