Proceedings of the 2020 Mississippi Water Resources Conference

Year: 2020 Authors: Paul V., Vattikutti S., Sankar M.S., Dash P., Berry M., Arslan Z.

Metal pollution in water bodies is a matter of international urgency, owing to the many associated toxicological and environmental issues. Sediments in water bodies serve as an important storage point for many of these metals and could release the adsorbed/absorbed ions back to the water under favorable conditions. Comparing the concentration of metals in different aquatic bodies will help to evaluate the accumulation and distribution characteristics within these systems. We investigated trace metal accumulation in sediments obtained from different aquatic systems in the state of Mississippi to evaluate and compare their pollution and enrichment indices. Sediments from five different aquatic systems; agricultural ponds, man-made reservoir, river, swamp and coastal marine environment including bay region, were collected. Following total digestion of the sediments, the concentrations of eleven trace metals (Cr, Co, Cu, Zn, As, Se, Cd, Sb, Hg, Pb, and U) were analyzed using Inductively Coupled Plasma-Mass Spectrometer (ICP-MS). The coastal and agricultural ponds samples showed the highest degree of anthropogenic modification (enrichment factor >10), especially for metals Se, U, Hg, and Pb. The metals Hg and Pb were highly enriched in sediment samples of all five environments. The pollution load index calculated for each system showed that the agricultural ponds were progressively deteriorated with respect to the sediment quality (value >1). The metals Cd and U showed high contamination factor (>6) in one agricultural pond sample, indicating moderate to severe contamination. Overall, our data indicate that sediments in the river, forest and man-made reservoir systems contain relatively fewer metal pollutants when compared to agricultural ponds and coastal regions. Both agricultural ponds and coastal regions serve as collection points for fertilizers, and other chemicals that contain metals, thereby explaining the trend observed. The research provides one of the first studies comparing sediment quality within different water bodies and will help in future studies to narrow remediation efforts.