Removal of Ni (II) ions from water using scrap tire

The present study was undertaken to evaluate the potential of scrap tire as adsorbent for removal of nickel ions from water. The activated carbon prepared showed porous morphology and favorable surface chemistry for binding to Ni2+ ions. Batch studies demonstrated that under laboratory conditions, a 0.5 g/L adsorbent dose was found to be optimum at a pH of 7, contact time of 50 mins and temperature of 55 degrees C for achieving >= 95% Ni2+ removal from synthetic solution containing 0.1 ppm Ni2+ concentration. Practical applications using a metal fabricating industrial wastewater revealed that the developed adsorbent has the capability of removing not only 95% of Ni2+ ions but also other toxic metal ions present were removed to a significant extent. Langmuir isotherm model parameters showed a maximum adsorption capacity of 25 mg/g with the developed adsorbent under optimum conditions for Ni2+ removal. The adsorption process is believed to proceed by an initial surface adsorption followed by intraparticle diffusion. Thermodynamic studies revealed the feasibility and endothermic nature of the system. The results of the present study suggest that scrap tire can be used beneficially for nickel removal from aqueous solution. (c) 2013 Elsevier B.V. All rights reserved.