Utilization of cyanobacterial adsorbents for remediation of lead ions from contaminated water: Insights into bioremediation strategies
Abhijeet Mahana, Tapas Kumar Mandal, Debasish Das
Abstract
This study investigates the adsorption mechanism of lead ions (Pb 2+ ) on various forms of cyanobacterium Phormidium corium NRMC-50 adsorbents, such as exopolysaccharides (EPSs), capsular polysaccharides (CPSs), biomass without capsular polysaccharides (BCPSs), and native biomass (NB). An in-depth characterization of Pb 2+ -loaded adsorbents was carried out to understand the changes that might have happened in their functional groups, surface morphology, elemental composition , and surface charge , due to adsorption. Further, Langmuir, Freundlich, and One-site-specific binding models were applied to investigate the effects of environmental parameters namely, temperature, pH, and initial Pb 2+ concentrations on adsorption kinetics . Amongst all the adsorbents, polysaccharides exhibited the rapid removal efficiency of Pb 2+ , which might be attributed to the presence of functional groups such as carboxyl, hydroxyl , and amino groups in polysaccharides facilitating efficient Pb 2+ adsorption. EPS demonstrates a high potential for rapid Pb 2+ capture due to its high density of binding sites and substantial capacity. Box-Behnken model optimization confirms that pH and Pb concentrations in its environment significantly influence Pb 2+ adsorption. Overall, this study underscores the efficacy of cyanobacteria in bioremediation applications, offering a sustainable and effective approach to mitigating heavy metal contamination in water systems and contributing to develop more efficient wastewater treatment solutions.