Discipline: Ecology Environmental and Earth Sciences
Subcategory: Environmental Engineering
Room: Exhibit Hall A
Regina Winston - Claflin University
Co-Author(s): Anthony Rizzuti, Claflin University, Orangeburg, SC
Copper (Cu) is a toxic element which is present in many aquatic environments. Current Cu remediation technologies have high costs, may lack efficiency, or produce a concentrated sludge. There is a need for a cost-effective, environmentally friendly Cu remediation strategy. An emerging technique known as biosorption has been presented as both effective and inexpensive in comparison to chemical and physical technology, and various biosorbent materials have been found to work well at removing heavy metals from aqueous solutions. Sorghum plant has shown the potential to remediate heavy metals from aqueous solutions. The purpose of this research was to investigate the Cu biosorption potential of sorghum plant from aqueous solutions. Sorghum plant was mixed with Cu solutions. The liquid portion of the samples were then centrifuged; vacuum filtered; and analyzed for Cu concentration using ICP. Samples were tested unaltered, and after being treated with 10% HCL. Additional parameters tested include the absorbent sample dose (0.5g, 1.0g, 1.5g, and 2.0g), contact time between samples and Cu solutions (2hrs, 24hrs, 48hrs), mixing temperature (24, 30, 35, and 40°C), concentrations of the Cu solutions (1ppm, 5ppm, 10ppm, 20ppm, and 30ppm), sample particle size (<10mesh, 10-20 mesh, and >20 mesh), and pH of the Cu solutions (2-10). The results of this study indicate that sample dose did not have a significant impact on the sorghum plant’s ability to remove Cu from solution (68% removal for 0.5g – 67% removal for 2.0g). As contact time increased the percentage of Cu removed increased as well (69% removal for 2 hours – 81% removal for 48 hours). As particle size decreased the percent of Cu removed increased (60% removal for <10 mesh samples – 68% removal for samples that were >20 mesh). As mixing temperature increased the percent of Cu removed increased as well (68% at 24°C – 80% at 40°C). Acid-treated samples removed a slightly higher percentage of Cu than non-acid-treated samples (acid-treated samples 76% removal versus 68% removal for non-acid-treated samples). As the Cu solution concentration was increased, the sorghum plant Cu biosorption capacity significantly decreased (96% removal for 1ppm solution – 68% removal for 30ppm solution). As the pH of the Cu solution was increased from 2-9 the Cu biosorption capacities of the hulls increased (8% removal for pH2 solution – 76% removal for pH9 solution). At pH 10 the percentage of Cu removed decreased to 59%. Desorption results showed a 76% Cu recovery rate. Reused sorghum plant were less effective at removing Cu without going through desorption (38% less effective), and 13% more effective after going through desorption. In addition, the sorghum plant that did not go through desorption were still less effective at removing Cu from solution when they were reused twice for Cu biosorption (33% Cu removal). Overall, sorghum plant exhibited a great potential to use as a biosorbent of Cu from aqueous solutions.
Funder Acknowledgement(s): This study was supported, in part, by a grant from the DOE awarded to Dr. Rebecca Bullard-Dillard, former Associate Vice Provost of Claflin University, Orangeburg, SC.
Faculty Advisor: Anthony Rizzuti, firstname.lastname@example.org
Role: I assisted in all aspects of research.