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.

中文翻译：

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铬（VI）和铅（II）离子的解吸和废吸附剂的再生

通过各种解吸洗脱液（如自来水，去离子水，NaOH，HCl和H ₂ SO）测试了花生壳上先前吸附的六价铬[Cr（VI）]和二价铅[Pb（II）]离子的解吸特性。₄。其中，由于HCl和H ₂ SO ₄的高解吸效率，它们分别被选作Cr（VI）和Pb（II）离子的最佳解吸剂。HCl和H ₂ SO ₄的解吸效率两种洗脱剂的浓度为0.1 M时，Cr（VI）和Pb（II）离子的离子浓度分别约为76.1％和82.1％。耗尽的花生壳可再生至五个循环，而在第三循环中，回收的花生壳上的Cr（VI）和Pb（II）离子的去除效率可分别保持在53.5％和54.6％。在第三次循环后，连续的再生循环导致Cr（VI）和Pb（II）离子的解吸效率分别降低了20.0％和26.7％。结果表明，花生壳可用于从受Cr（VI）和Pb（II）污染的水和废水中去除Cr（VI）和Pb（II）离子。