Field, Laboratory, and Modeling Assessment of Metals Treatment via Iron AdditionDIntegral Consulting Inc., Broomfield, Colorado, USA

摘要

Iron, in the form of hydrous ferric oxide (HFO), is well known as a dominant sorbent of metals in the environment—a phenomenon that is exploited by numerous metals treatment technologies. Iron adsorption has long been applied to remove metals by the water treatment industry and more recently in situ applications have been developed for the remediation of metal-contaminated groundwater and soils. This study presents the results of laboratory and field treatability testing conducted on three different aqueous systems: acid-rock drainage from a Nevada gold mine, a landfill leachate, and a simulated metals-impacted groundwater. Results of the tests demonstrate that iron addition is an effective means for metals removal under a wide range of water chemistries. Owing to the amphoteric nature of HFO, removal efficiency was strongly influenced by pH. Further, the presence of competing solutes was found to reduce removal efficiency. This was particularly pronounced for the landfill leachate, in which the removal of arsenic was strongly inhibited by the presence of phosphate.