SEM-EDS Elemental Mapping of Weymouth Soils
EMSL Project ID
16723
Abstract
During operation of the former Weymouth phosphate fertilizer plant, sulfuric acid was produced to dissolve phosphate ore. The sulfuric acid was produced from Fe sulfide ore which was composed primarily of pyrite (FeS2). Also present in the Fe sulfide ore at lower concentrations were arsenopyrite (FeAsS), galena (PbS), and sphalerite (ZnS). As a result of these processes used at the Weymouth plant, site soils are highly contaminated with Pb, As, and Zn. XRD analysis indicated the presence of hematite, quartz, muscovite, clinoclore, corkite, franklinite, and possibly anglesite, and jarosite. Selective extractions combined with geochemical modeling suggests that a signficant amount of ferrihydrite is present and it has adsorbed significant amounts of the metal contaminants. Three remediation technologies are proposed to immobilize the contaminants in-situ. SEM-EDS elemental mapping is proposed to gain a better understanding the the associations between the three major contaminants and the major soil component phases in the untreated soils and to evaluate the changes in contaminant speciation that occur as a result of the treatment processes. Three untreated samples will be examined as well as samples treated by the three treatment processes in bench scale tests for a total of 12 samples.
Project Details
Project type
Exploratory Research
Start Date
2005-11-07
End Date
2007-07-06
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members