Kinetic study on adsorption of Cr(VI), Ni(II), Cd(II) and Pb(II) ions from aqueous solutions using activated carbon prepared from Cucumis melo peel

M Manjuladevi,S Manonmani,R Anitha

doi:10.1007/s13201-018-0674-1

Abstract

The adsorption of Cr(VI), Ni(II), Cd(II) and Pb(II), ions from aqueous solutions by Cucumis melo peel-activated carbon was investigated under laboratory conditions to assess its potential in removing metal ions. The adsorption behavior of metal ions onto CMAC was analyzed with Elovich, intra-particle diffusion rate equations and pseudo-first-order model. The rate constant of Elovich and intra-particle diffusion on CMAC increased in the sequence of Cr(VI) > Ni(II) > Cd(II) > Pb(II). According to the regression coefficients, it was observed that the kinetic adsorption data can fit better by the pseudo-first-order model compared to the second-order Lagergren’s model with R2 > 0.957. The maximum adsorption of metal ions onto the CMAC was found to be 97.95% for Chromium(VI), 98.78% for Ni(II), 98.55% for Pb(II) and 97.96% for Cd(II) at CMAC dose of 250 mg. The adsorption capacities followed the sequence Ni(II) ≈ Pb(II) > Cr(VI) ≈ Cd(II) and Ni(II) > Pb(II) > Cd(II) > Cr(VI). The optimum adsorption conditions selected were adsorbent dosage of 250 mg, pH of 3.0 for Cr(VI) and 6.0 for Ni(II), Cd(II) and Pb(II), adsorption concentration of 250 mg/L and contact time of 180.

Highlights

Heavy metal ions such as Cr(VI), Ni(II), Zn(II), Cd(II) and Pb(II) are among the toxic inorganic pollutants that may cause environmental problem, at low concentration in surface or subsurface water (Gupta and Nayak 2012; Gupta and saleh 2013; Gupta et al 2013, 2015; Jain et al 2003; Vinod et al 2012; Saleh and Gupta 2012a)
The present work is aimed to analyze the role of the surface chemistry in creating the activated carbon surface–metallic species interactions that govern the adsorption of Pb(II), Cd(II) and Ni(II) heavy metal ions
The adsorption behavior of heavy metals on CMAC was analyzed with Elovich, intraparticle diffusion model, Lagergren firstorder model

Summary

Introduction

Heavy metal ions such as Cr(VI), Ni(II), Zn(II), Cd(II) and Pb(II) are among the toxic inorganic pollutants that may cause environmental problem, at low concentration in surface or subsurface water (Gupta and Nayak 2012; Gupta and saleh 2013; Gupta et al 2013, 2015; Jain et al 2003; Vinod et al 2012; Saleh and Gupta 2012a). Adsorption is a simple treatment method for removing metal ions in wastewater, and activated carbon is a. The present work is aimed to analyze the role of the surface chemistry in creating the activated carbon surface–metallic species interactions that govern the adsorption of Pb(II), Cd(II) and Ni(II) heavy metal ions. The adsorption behavior of heavy metals on CMAC was analyzed with Elovich, intraparticle diffusion model, Lagergren firstorder model

Methods

Results

Conclusion