Optimization of physical parameters for batch mode Zn (II) ion removal from liquid phase: A potential biosorption study


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The present investigation has been undertaken for the evaluation of biosorption capacity of zinc sequestering bacteria VMSDCM (Accession Number. HQ108109). The maximum biosorption capacity and percentage removal of Zn (II) ion from liquid phase in batch mode were 0.21 mol g−1 and 100%, respectively, obtained at optimized pH 7, 308 K, adsorbate dose 7 mol L−1, adsorbent dose 1 g L−1, and contact time 8 h. Fourier transformation infrared (FTIR) and scanning electron micrograph (SEM) analyses revealed the fact that the surface of bacterial mass was noncrystalline, amorphous, and enriched with negatively charged viz amino, carboxyl, amide, immidazolic, hydroxyl, and ketonic groups before the metal ion sorption. The bacterial surface became crystalline, smooth without protrusions after the sorption of Zn (II) ion onto surface of bacterium, and the reflectance of FTIR spectrum shifted from original location indicating the involvement of negatively charged surface groups in metal ion binding. The maximum inhibitory concentration (MIC) in the present work was 8 mol l−1 for this bacterium. © 2012 American Institute of Chemical Engineers Environ Prog, 32: 213-222, 2013