Sorption of Toxic Cr(VI) From Aqueous Solutions by Using Treated Acacia nilotica Leaf as Adsorbent: Single and Binary System

The use of cheap and eco-friendly adsorbents prepared from freely and abundantly available Acacia nilotica leaves for the removal of highly toxic Cr(VI) from aqueous solutions in single and binary ion solutions as well as from a mixture of it with Co(II) & Cu(II) was investigated by batch methods. The effects of pH, contact time, and initial metal ion concentration of Cr(VI) onto H2SO4-treated Acacia nilotica leaves (HAN) was investigated. The linear form of the Freundlich model achieved high coefficients of determination R2 = 0.9808 for Cr(VI) adsorption. The R2 values for fitting the adsorption rate data were greater than 0.983 for Cr(VI) ion, which indicates the applicability of pseudo-second-order kinetic model. The desorption and recycling ability of Cr(VI) and HAN were found to be good. The studies showed that this low-cost adsorbent could be used as an efficient adsorbent material for the removal of Cr(VI) from aqueous solutions.