Biosorption of heavy metal ions from the aqueous solutions using groundnut shell activated carbon: batch adsorption, kinetic and thermodynamic studies

Batch adsorption studies of heavy metals were carried out using activated charcoal groundnut shell powder as an adsorbent material. The groundnut shell was collected and synthesized by chemical synthesis to convert it into charcoal form. The prepared adsorbent's pore size & surface area was analyzed by BET surface analysis using N2 - adsorption & desorption process. XRD techniques analyzed the crystalline structure of charcoal adsorbent, and the functional groups & behaviour of the surface were analyzed through FTIR, SEM, and EDX analysis. The optimum adsorption parameters of pH, temperature, time of contact between adsorbent and adsorbate, groundnut shell dose, and metal ion concentrations were obtained from the batch studies with an optimum concentration of 20 mg/L, and the mass transfer mechanism and rate controlling step was identified by isotherm and kinetic studies. The adsorbent with the dose of 2.5 g L-1 removed 87.12% of Cu ions, 92.28% of Pb ions and 95.62% of Hg ions at the pH of 2.0 with 25 mg L-1 concentrated metal ions in the synthetic solution.