682 J SCI IND RES VOL 71 OCTOBER 2012 Journal of Scientific & Industrial Research Vol. 71, October 2012, pp. 682-689 *Author for correspondence E-mail: *kemckayg@ust.hk Adsorption of acid black 1 by using activated carbon prepared from scrap tires: kinetic and equilibrium studies Edris Hoseinzadeh 1 , Ali Reza Rahmanie 2 , Ghorban Asgari 2 , Gordon McKay 3 * and Ali Reza Dehghanian 4 Department of Environmental Health Engineering, Faculty of Health, Lorestan University of Medical Sciences., Khorramabad, Iran. Department of Environmental Health Engineering, School of Public Health, Centre for Health Research, Hamedan University of Medical Sciences, Hamadan, Iran. Environmental Health Engineering, Shiraz Health Center, Shiraz University of Medical Sciences Shiraz, Iran. Department of Chemical and Biomolecular Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong. Received 17 April 2012; revised 12 June 2012; accepted 3 September 2012 The effects of initial dye concentration, pH, contact time and the adsorbent dosage were studied. The chemical composition and solid structure of the activated carbon were analyzed using scanning electron microscope (SEM) imaging coupled with energy dispersive spectrometry (EDS). The surface area was measured using Brunauer-Emmett-Teller (BET) isotherm. Experimental adsorption isotherms were well fitted by Langmuir model and maximum adsorption capacity (Qm) for AB1was found to be 14.51 mg g -1 . The kinetic studies showed that the adsorption of AB1 complies with the pseudo-second-order kinetic model (R 2 > 0.9999). Keywords : Adsorption, Activated Carbon, Scrap tires. Introduction Almost 250,000 tons per year of scrap tires are produced in Iran: 1 but only 21% is recycled 2 . The typical compounds are shown in Table 1. Stored scrap tires cause environmental problems such as: the accumulation of insects and flies; ignition of such tires and illegal dumping 3 . There are many opportunities for producing new products, such as activated carbon using scrap tires as a cheap and abundant resource. The amount of fixed carbon (almost 25% of mass), and a small amount of ash (<5%) in tire plastic is an advantage for producing activated carbon 4 . Also, pyro-oil and pyro-gas produced by pyrolysing of scrap tires is a recyclable source of energy 5 . Value added activated carbon from scrap tires can be used in industries to improve to air quality and also for wastewater treatment. Producing activated carbon from scrap tires has an economic benefit and an environmental one. Activated carbon can be used to treat dye wastewater in the textile industries and other industries which use dyes and dye pigments 6 . Most of the dyes are not biodegradable due to their complex ring structure 7, 8, 9 consequently treating dye wastewater is difficult 10 . The presence of dye in the effluent prevents sunlight penetration into the water and as a result interferes with photosynthetic processes in shallow water resources 11, 12 . Besides some of the dyes or their metabolites have toxin, mutation and cancerous characteristics. Some studies have reported respiratory and skin disorders due to dyes 13 . Acid dyes are considered hazardous in textile industries 14 . The general aim of this study is to produce powdered activated carbon from scrap tires by pyrolyzing, define its features and study its ability to remove Acid Black1 (AB1) from aqueous solutions as an Azo dye. This study also consists of determining the isotherm and adsorption kinetics, the effect of initial dye concentration, adsorbent dosage, contact time, and pH in the function of eliminating this pollutant with the produced activated carbon from scrap tires. Materials and methods Instruments A digital balance with precision of ±0.0001g (model Sartorius ED124S) was used for weighing the materials.