Analysis of trace elements pollution within streambed sediments from the Shade River Watershed, southeastern Ohio

摘要

Streambed sediments collected from the Shade River Watershed within the Western Allegheny Plateau in Meigs and Athens counties (Ohio, USA) were analyzed for trace elements. Different pollution indices and statistical techniques were used to evaluate the relationship between the trace elements and determine their levels of contamination. The watershed was once mined for coal and has history of acid mine drainage (AMD). Treatment of this contamination is still being addressed by federal and local organizations. Sediment analyses indicated that iron, aluminum, and manganese, which are primary AMD species, are dominant within the sediments. Pollution indices indicated that the sediments were moderately to extremely polluted, with iron dominating. Relatively low trace element concentrations in the Middle Shade River can be attributed to the intense remediation or treatment of mine drainage. Although trace elements' concentration in the Shade River Watershed was greater than their respective background values, the relationship between iron and other trace elements indicates that alkaline pH and redox conditions can influence the neutralization of AMD, and also result in the precipitation of iron and manganese oxide/hydroxides. This may have caused the contamination of the streambed sediment apart from factors including local geology, erosion of agricultural soil, mine discharge, and other anthropogenic input into the watershed.