WITHDRAWN: Adsorption of Cr(VI) from aqueous solutions by using activated carbons prepared from Ricinus communis leaves: Binary and ternary systems

Abstract

The present study deals with the removal of Cr(VI) ion from aqueous solutions onto water washed raw leaves of Ricinus communis (RLRC) and microwave assisted zinc chloride acti- vated leaves of R. communis (ZLRC). The adsorbent has been characterized with FTIR, SEM- EDAX and XRD studies. Adsorption experiments were carried out systematically by batch exper- iments to investigate the influence of different factors, such as contact time, initial concentration of metal ions, and pH of the solutions. The influence of other metal ions on the adsorption of Cr(VI) ions was investigated. Adsorption capacity of the binary and ternary metal ions tested on RLRC and ZLRC was low as compared to single metal ions. The maximum adsorption of Cr(VI) was observed at pH 7.05 for RLRC (47.37%) and ZLRC (58.97%). The adsorption of Cr(VI) ions from aqueous solutions on RLRC and ZLRC could be favorably described by the Langmuir isotherm, the adsorption kinetics was well fitted in pseudo-second order and intra particle diffusion model. We investigate the recovery of the used adsorbent for its reuse is of great importance for environ- mental and economical reasons. i.e., RLRC and ZLRC will be recovered by the desorption method by using a proper desorption agent like H2O by batch mode study. Among RLRC and ZLRC, ZLRC shows the most adsorption ability than RLRC. According to the experimental results, the adsorbent derived from this material is expected to be an economical product for metal ion reme- diation from water and waste water. a 2014 Production and hosting by Elsevier B.V. on behalf of King Saud University.