Long-Term Removal and Retention of Iron and Manganese from Acidic Mine Drainage by Wetlands. Volume 2. Tarutis Thesis

摘要

The behavior of sedimentary iron and manganese in a volunteer wetland receiving mine drainage on a reclaimed coal surface mine in Pennsylvania was characterized to determine if these metals can be retained in the sediments. Five metal fractions sensitive to changes in environmental conditions were examined. The potential for the association of iron and manganese with organic carbon and sulfur was studied to evaluate diagenetic changes important to metal cycling in wetland sedimentary environments. The aerobic zone was characterized by an abundance of iron and manganese oxides, organic carbon, and sulfur in the sediment, and virtually no dissolved iron and manganese in the interstitial water. The anaerobic zone was characterized by relatively low levels of iron and manganese oxides and a concomitant increase of dissolved iron and manganese in the interstitial water. The low concentration of metal sulfides and the high carbon/sulfur ratios observed suggest that sulfate reduction was a relatively unimportant process for metal removal. In the wetland studied, the aerobic zone was more important in metal retention than the anaerobic zone based on the results of multivariate analysis.