In Situ Biological Treatment of Hexavalent Chromium in Shallow Aquifer Using Emulsified Vegetable Oil

摘要

Background/Objectives. In November 1986, a train derailment resulted in the release of significant quantities of methanol, sodium dichromate, ethylene glycol and chromic acid. Much of the materials released were contained through emergency response activities and removal of impacted soil and track ballast; however the shallow aquifer was impacted by hexavalent chromium (Cr(VI)) dispersion from the sodium dichromate and chromic acid. A groundwater recovery and treatment system consisting of an ion exchange system was constructed and operated from 1990 through 1996. From 1997 through 2008, monitored natural attenuation was implemented as the remedial alternative. In 2011, a pilot study was conducted to demonstrate enhanced bioremediation using emulsified vegetable oil (EVO).