Desorption of chromium (VI) and lead (II) ions and regeneration of the exhausted adsorbent

Jonas Bayuo,Kenneth Bayetimani Pelig-Ba,Moses Abdullai Abukari

doi:10.1007/s13201-020-01250-y

Abstract

The desorption characteristics of previously adsorbed hexavalent chromium [Cr(VI)] and divalent lead [Pb(II)] ions on groundnut husk were tested by various desorption eluents such as tap water, de-ionized water, NaOH, HCl and H2SO4. Among them, HCl and H2SO4 were chosen as the best desorbing agents for Cr(VI) and Pb(II) ions, respectively, due to their high desorption efficiency. The desorption efficiency of HCl and H2SO4 for Cr(VI) and Pb(II) ions was about 76.1% and 82.1%, respectively, at a concentration of 0.1 M for both elution agents. The exhausted groundnut husk was regenerated up to five cycles, and the removal efficiency of Cr(VI) and Pb(II) ions on the recycled groundnut husk could be maintained at 53.5% and 54.6%, respectively, in the third cycle. The successive regeneration cycles resulted in the reduction of the desorption efficiency by 20.0% and 26.7% for Cr(VI) and Pb(II) ions, respectively, after the third cycle. The results show that groundnut husk could be recycled when used to remove Cr(VI) and Pb(II) ions from Cr(VI) and Pb(II)-polluted water and wastewaters.

Highlights

Environmentalists and government agencies both locally and globally are worried about the health risks accompanying heavy metals poisoning in living organisms and underscore the need for continuous research intending to combat the problems of environmental pollution by these toxic metals
Desorption studies were conducted to select the optimum desorbing solution to be employed in successive regeneration cycles
The study indicated that Cr(VI) and Pb(II) ions accumulated onto the groundnut husk could be desorbed and maximum percentage recovery of Cr(VI) and Pb(II) ions was 76.1% and 82.1% with 0.1 M HCl and 0.1 M H2SO4, respectively

Summary

Introduction

Environmentalists and government agencies both locally and globally are worried about the health risks accompanying heavy metals poisoning in living organisms and underscore the need for continuous research intending to combat the problems of environmental pollution by these toxic metals. Contamination of natural environment by heavy metals has to turn out to be a major issue worldwide, and Ghana is no exception because of their toxicity and potential health risks posed to biological organisms when consumed beyond the acceptable limits (Prabha and Udayashankara 2014). The rapid population growth along water sources in Ghana has necessitated proper conservation and efficient utilization of freshwater bodies due to heavy metals and other toxic chemicals. This is because there has been accelerated deterioration of water quality within water bodies due to increased domestic, municipal, industrial, mining and agricultural activities (Dadzie 2012). When agricultural soils are polluted, these metals are taken up by plants and accumulate in their tissues (Trüby 2003)

Methods

Results

Conclusion