Sorption Studies of Bromate Removal from Water by Nano–Al₂O₃

Abstract

The feasibility of nano–Al₂O₃ for bromate removal from aqueous solution was assessed in the present study. Batch sorption experiments were performed to examine the influence of various experimental parameters such as contact time, initial bromate concentration, temperature, and pH on the sorption of bromate on nano–Al₂O₃. Kinetic data revealed that the uptake rate of bromate was rapid in the beginning and 50% adsorption was completed within 10 min and equilibrium was achieved within 120 min. Pseudo–second–order kinetic model was fitted well with the kinetics of the sorption process. The sorption potential of nano–Al₂O₃ for bromate removal was ∼6.0 mg g⁻¹. The adsorption was found to be an endothermic process and data conform to the Langmuir model.

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Keywords:

• bromate sorption
• isotherms
• kinetics
• nano–adsorbent
• thermodynamic studies

ACKNOWLEDGEMENTS

We wish to thank all the anonymous reviewers whose comments/suggestions have significantly improved the quality of this manuscript. Amit Bhatnagar acknowledges his post-doctoral scholarship (FCT–DFRH-SFRH/BPD/62889/2009) supported by the Portuguese Foundation for Science and Technology (FCT).

Notes

q _e : Amount of bromate adsorbed on nano–Al₂O₃ (mg g⁻¹) at equilibrium.

q _t : Amount of bromate adsorbed on nano–Al₂O₃ (mg g⁻¹) at time t (min).

k _f : Rate constant for the pseudo–first–order kinetics.

k _s : Rate constant for the pseudo–second–order kinetics.