Synthesis, Characterization and Application of Bio-composites Based on Aspergillus flavus NA9 for Extraction of Zinc Ions from Synthetic and Real Waste Water Effluents

Abstract

In present research report four types of biocomposites were synthesized and characterized by surface area analysis (SEM–EDX); porosity (BET), X-Ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). These synthesized bio-composites were further examined for Zn(II) removal and recovery in batch reactors followed by column experiments using industrial effluent. The Aspergillus flavus NA9 immobilized glutaraldehyde cross-linked calcium alginate beads (FGCAB) proved as a novel biosorbent with maximum uptake capacity of (324 ± 2.1) mg Zn(II)/g in the studied concentration range (100–600 mg of Zn(II)/L). The chemistry of Zn and FGCAB interaction was studied using SEM–EDX and XRD analysis. Isotherm models used to analyze the data generated in batch bioreactors showed a best fit to Freundlich isotherm. Column studies depicted maximum 89.6% Zn(II) recovery with FGCAB using 0.01 M HCl. The column containing 1.5 g dry weight of FGCAB purified 5.25 L of paint industry effluent (9.58 mg Zn(II) /L before breakthrough occurred and became saturated after 11 L of influent, which revived upto three sorption–desorption cycles. Thus, A. flavus NA9 immobilized glutaraldehyde cross-linked alginate beads could be promising sorbent for treatment of Zn(II) contaminated industrial waste stream.