Suitability of various chemically prepared activated carbons for the removal of copper(II) ions

Abstract

Studies on the suitability of various chemically prepared activated carbons (CPACs) like straw carbon (SC), sawdust carbon (SDC), dates nut carbon (DNC) and commercial activated carbon (CAC) for the removal of copper(II) ions by adsorption from simulated wastewater have been carried out under batch mode at 30 ± 1°C and the results are compared. The percentage removal of Cu(II) ions increased with a decrease in initial concentration, particle size and added electrolytes (ionic strength) and increased with an increase in contact time, dose of adsorbent and initial pH of the solution. The adsorption data were fitted with the Langmuir isotherm. The applicability of the first order kinetic equation viz. Lagergren equation was tested by correlation analysis. The adsorption process is concluded to be a spontaneous, first order reaction, occurring with increased randomness at the solid–liquid interface. Studies on the desorption of Cu²⁺-loaded activated carbons (ACs) were carried out with nitric acid (0.2–1 N). The possibility of reuse of the regenerated ACs in cycle (in cue-one after another) was tested. SC was found to be a suitable adsorbent alternative to CAC among CPACs for the removal of metal ions, in general, and Cu²⁺ ions, in particular.

Keywords:

• Adsorption
• removal of Cu(II) ions
• chemically prepared activated carbons (CPACs)
• straw
• saw dust and dates nut carbons
• Langmuir isotherm
• Lagergren equation
• desorption and reuse

Acknowledgements

The authors are highly thankful and grateful to the Principal and Management of their colleges for constant encouragement and also for providing research facilities. The authors are grateful to UGC, New Delhi and UGC – SERO, Hyderabad, A.P. for providing financial assistance to one of them (G.R.) under UGC – FDP scheme. The authors also gratefully acknowledge the reviewers for their good suggestions and comments for the revision of the article.