Insight to rapid removal of Pb(II), Cd(II), and Cu(II) from aqueous solution using an agro-based adsorbent Sorghum bicolor L. biomass

ABSTRACT

The present study proposed the adsorption characteristics of Pb(II), Cd(II), and Cu(II) on to Sorghum bicolor L. (commonly, Charee in Pakistan) biomass from aqueous solutions. The influence of different process parameters, such as the adsorbent dose, solution pH, contact time, agitation speed, and initial metal ion concentration, were studied thoroughly to evaluate optimum conditions for adsorption. Maximum adsorption for all metal ions has taken place at pH 5.0–6.0. Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich isotherm models in a nonlinear fashion were used to explain the phenomenon. Maximum adsorption capacity of Sorghum bicolor L. biomass was 6.289 mg/g, 7.87 mg/g, and 4.34 mg/g for Pb(II), Cd(II), and Cu(II), respectively. Adsorption mechanism was explored by pseudo-first-order and pseudo-second-order kinetic models and it was found that the process followed pseudo-second-order kinetics. Thermodynamic study indicated the process favorability. The study concluded that the Sorghum Bicolor L. can be an effective adsorbent for removing toxic metals from water owing to the fine adsorption capacity.

Keywords:

• Sorghum Bicolor L.
• Nonlinear isotherms
• D–R model
• Mean free energy
• Thermodynamics

View correction statement:

Insight to rapid removal of Pb(II), Cd(II), and Cu(II) from aqueous solution using an agro-based adsorbent Sorghum bicolor L. biomass [Desalination and Water Treatment, Volume 51 (2013) 4390–4401]∗