Corn Silk as Biosorbent for Pb, Zn and Cu Removal: Batch and Fixed-bed Column Study

Abstract

In this study, the minimization of heavy metal pollution was investigated. Accordingly, potential of corn silk as biosorbent of Pb, Zn and Cu from multimetal solution was considered in batch and fixed-bed column experiments. Structural changes of corn silk before and after heavy metal removal were determined using SEM-EDX and FTIR analyses. For investigation of biosorption performance the Langmuir and Freundlich isotherm models were applied at batch experimental results. Fast biosorption process and high adsorption capacity (0.382; 0.200 and 0.171 mmol g-1 for Pb2+, Cu2+ and Zn2+, respectively) confirmed that the corn silk is suitable for heavy metals removal. In order to produce a novel and improved column package for fixed-column bed study implementation, the corn silk was immobilized with alginate. The fixed-bed column was saturated with Pb-Cu-Zn multimetal solution. The breaktrought time is 95, 100 and 90 min for Pb2+, Cu2+ and Zn2+ respectively, where 87.5, 81.9 and 95.5% Pb2+, Cu2+ and Zn2+ was removed, respectively. Desorption sudy was performed in HNO3 (p.a.) solution where high desorption efficiency (>94%) confirmed that imobilized corn silk can be used as alternative material for metal adsorption and could be applied in purification systems.