Biosorption of Co (II) ions from aqueous solutions using selected local Luffa Cylindrica: Adsorption and characterization studies

The present study is concerned with the removal of Cobalt (II) from aqueous solution by adsorption onto low cost adsorbent. Luffa Cylindrica as adsorbent, (LC) was investigated in batch adsorption system. LC was characterized by Scanning Electron Microscopy (SEM) and Brunauer-Emmett-Teller (BET) surface area analyzer. The sorption of Co (II) ions by LC was subjected to equilibrium, thermodynamics and kinetic studies and was carried out by considering the effects of pH, effect of masse and particles size of the biosorbent, initial metal ions concentration, contact time and temperature. BET surface area of LC was 46.396 m(2)/g. The optimum conditions for maximum adsorption were attained at pH 6 and LC mass is 1.5 g with particle size is < 0.08 mm and contact time is 60 min. The pseudo-second-order rate equation described the Kinetic data well. The process is chemisorptive and controlled by the pseudo-second-order. Adsorption parameters were determined using both Langmuir and Freundlich isotherms, but the experimental data were better fitted to the Langmuir equation than to Freundlich equation, with correlation coefficients above 0.99 which indicates the adsorption is monolayer adsorption with maximum adsorption capacity for Co(II) was 2.53 mg/g.