Enhancing adsorption of Pb(II) from aqueous solution by NaOH and EDTA modified Artocarpus odoratissimus leaves

Leaves of Artocarpus odoratissimus have successfully undergone surface chemical modification using a base (NaOH) and a chelating agent (EDTA) via a single and double modification. The modified adsorbents were investigated for their potential use in adsorbing Pb(II) from simulated wastewater and were tested through several adsorption parameters such as pH, ionic strength, interference effect, regeneration and column (dynamic) studies. The adsorption of Pb(II) by the adsorbents was excellent where the removal of Pb(II) was almost resilient to change of pH, except at pH 2, and unaffected by the presence of other metal ions. Further, the adsorbents can be regenerated using acid and base, maintaining good adsorption even at the 4th cycle. The dynamic study concluded that column containing higher bed heights of the adsorbent took more lime to exhaust and able to adsorb more volume of the Pb(II). Adsorption isotherm data point to double modified adsorbent has higher adsorption capacity than the untreated and single modified adsorbents. This study also showed that the kinetics of all the adsorbents was following pseudo-second order indicating that the adsorption processes were all chemisorption.