Accession Number:

ADA512771

Title:

Reduced Iron Sulfide Systems for Removal of Heavy Metal Ions from Groundwater

Descriptive Note:

Final rept.

Corporate Author:

MICHIGAN UNIV ANN ARBOR DEPT OF CIVIL AND ENVIRONMENTAL ENGINEERING

Report Date:

2009-07-01

Pagination or Media Count:

225.0

Abstract:

In this research, we have evaluated iron sulfide for treating heavy metal contaminated groundwater plumes for PRB systems. Our approach was to test the effectiveness of reduced iron sulfide FeS as both a sorbent and reducing agent in PRB applications for long-term sequestration of heavy metal ions. Cadmium Cd and Arsenic As were the targeted contaminants. Mechanistic information on the metal removal mechanisms was obtained by molecular-scale surface techniques including synchrotron-based XAS and XRD, and microscopic tools such as HRTEM and SEM-EDS. FeS performance under various geochemical conditions was investigated using batch and column reactor systems. Two different forms of reactive sorbent media were prepared, nanoscale FeS and FeS-coated sand for two emplacement methods, colloidal injection and physical packing of porous media, respectively. Rejuvenation of FeS using sulfate reducing micro-organisms for biogenic formation of FeS from iron oxidation products was examined and shown to be feasible. Finally, a reactive transport model was developed using batch isotherm and column arsenic breakthrough data. The overall results provide tools needed to design and apply the FeS PRB media for effective long-term treatment of mixed-metal ion plumes at contaminated groundwater DOD sites.

Subject Categories:

  • Hydrology, Limnology and Potamology
  • Water Pollution and Control

Distribution Statement:

APPROVED FOR PUBLIC RELEASE