Adsorption of Heavy Metal Ions on Pomegranate (Punica Granatum) Peel: Removal and Recovery of Cr(VI) Ions from a Multi-metal Ion System

Abstract

ABSTRACT:The fruit peel of pomegranate (Punica granatum) exhibits a high affinity for Cu(II), Ni(II), Cd(II) and Zn(II) ions. The maximum adsorption observed was that of Cu(II) ions, followed by Zn(II), Cd(II), Ni(II) and Cr(VI) ions. The adsorption of Cu(II) ions was dependent on the initial Cu(II) ion concentration, pH, adsorbent dose, temperature and contact time. The adsorption isotherms could be described by the Langmuir and Freundlich equations. Application of the χ 2 -test indicated that both these models were best obeyed at 20 ºC. Thermodynamic parameters such as ∆H 0 , ∆S 0 and ∆G 0 were evaluated, the adsorption process being endothermic and spontaneous in nature. The value of the mean free energy indicated that the adsorption process was chemical in nature. Kinetic data showed that the pseudo-second-order model provided the best fit for the experimental data. Attempts were made using batch and column methods to desorb Cu(II), Ni(II), Zn(II), Cd(II) and Cr(VI) ions from synthetic wastewater as well as from wastewater derived from electroplating activities. The breakthrough capacities of Cu(II), Ni(II), Zn(II), Cd(II) and Cr(VI) ions were 6, 2, 2, 2 and 0 mg/g, respectively, when a mixture of these metal ions was treated. The adsorbent was utilized to recover Cr(VI) ions from electroplating wastewater.

Agricultural waste peels as versatile biomass for water purification – A review

“…The pomegranate peel was also tested for Cu(II), Ni(II), Cd(II), Zn(II) and Cr(VI) ions [105]. The maximum adsorption was observed for Cu(II) ions, followed by Zn(II), Cd(II), Ni(II) and Cr(VI)…”

Pomegranate peels as versatile adsorbents for water purification: Application of box–behnken design as a methodological optimization approach

“…Few studies have been reported on the application of PGP for removal of different HMs from water samples. Peels were used as such (untreated) or after modification (chemically or thermally) [16][17][18][19][20][21][22][23].…”

Adsorption characteristics of chemically modified Caryota urens seeds for the removal of Cu(II) from aqueous solution: Isotherms and kinetic studies

“…If the plot does not pass through the origin then it is concluded that chemical reaction or film diffusion controls the rate of adsorption (Rao and Rehman, 2010). In the present case the plot of Bt versus time did not pass through origin (Fig.…”