Effect of Different High Lead Concentrations on the Effectiveness of Biosorption Via Pre-treated and Untreated Dead C. vulgaris Biomass

Abstract:

Lead pollution from lead acid battery (LAB) recycling is the worst form of chemical pollution in developing countries and degrades both human health and the environment. A cost-effective and renewable method of lead removal is bioremediation by Chlorella vulgaris. Its bioremediation ability is improved by HCl pretreatment, which is expensive and time-consuming. Previous studies regarding the benefit of treatment have only been conducted on low concentrations of lead and have produced negligible differences. These studies have not considered the high concentration of lead pollution that is caused by unregulated LAB recycling pollution in developing countries. My study tests out the effectiveness of pre-treated Chlorella vulgaris to remove high concentrations of lead pollution that originates from unregulated LAB recycling. Chlorella vulgaris biomass was mixed with different lead nitrate solutions and measured for lead concentration post bioremediation. Chlorella vulgaris present in the lead solution was centrifuged out, and this solution was tested for pH and conductivity and used in lettuce seed bioassays. The difference in removal efficiency between pre-treated and untreated algae for 20mg/L was 14%, while the 40mg/L trials had a difference of 44% and the 60mg/L trials had a difference of 36%. The findings indicate that treatment for algal bioremediation is not necessary in regions with 20mg/L lead pollution like parts of Zambezi River but is needed in areas in Kenya which have lead pollution near 40mg/L or above. This principle can be applied to determine an effective lead pollution removal strategy with algal bioremediation.