RÉSUMÉ
Heavy metal ions pose significant risks to human health, pelagic, and several other life forms due to perniciousness, tendency to accumulate, and resistance to biodegradation. Waste bio-materials extend a budding alternative as low-cost adsorbent to address the removal of noxious pollutants from wastewater on account of being cost-effective and exhibiting exceptional adsorption capacities. The current exploration was accomplished to gauge the performance of raw and modified human hair concerning lead scavenging in a down-flow fixed bed column. The appraisal of column performance under varying operational parameters encompassing bed height (15-45 cm), influent metal ion concentration (60-140 mg L-1), and a solution flow rate (20-40 mL min-1) was performed by breakthrough curve analysis. The consequences acquired were evaluated using the Yoon Nelson, Thomas, Adam-Bohart, and Bed Depth Service Time (BDST) model. Among these employed models, Bed Depth Service Time (BDST) and Thomas models exhibited the highest R-squared value compared to the Yoon Nelson and Adam-Bohart's model for most cases. In addition, the optimization of lead adsorption was followed using the Box-Behnken design of response surface methodology (RSM). The optimal conditions (desirability-1.00) for achieving a goal of maximum percent removal of lead ions were marked to be a bed height of 42.79 cm, solution flow rate of 20.92 mL min-1, and an initial metal concentration of 139.51 mg L-1. Under these optimized conditions, the percent amputation of lead in a fixed bed was observed to be 82.31 %, while the results of the experiment performed approximately under these optimized conditions revealed a percent removal of 85.05 %, reflecting a reasonable conformity with values acquired through Box-Behnken design.