APPLICATION OF ACID MODIFIED RED MUD FOR LEAD ION REMOVAL FROM AQUEOUS SOLUTION

Abstract

In this study, the Pb(II) adsorption experiments with the single acid modified red mud were conducted as a function of initial pH, adsorbent doses, contact time, initial Pb(II) concentrations, and competitive ions. The adsorption results pointed that the highest Pb(II) removal efficiency was achieved at the initial pH 4.0, adsorbent dose 7.5 g/L, shaking speed 150 rpm and contact time around 60 minutes at the room temperature. The adsorption results arrowed that the Pb(II) removal efficiency of the modified red mud was enhanced to 150% compared to the raw red mud. The adsorption capacity of the modified red was measured of 9.52 mg/g, higher compared to several previous studies using the same method and type of acid. The study also indicated that the Pb(II) adsorption kinetic and isotherm were best described by the Pseudo - second - order kinetic and fitted to linearly transform both Langmuir and Freundlich with correlation coefficient (R2) over 0.99. The data obtained in this study indicated that modified red mud by using acid can be used as an effective and low cost adsorbent for heavy metals removal from wastewater.