Grantee Research Project Results
2004 Progress Report: Environmental Risk Assessment of Phosphate-Based Remedial Technology in Metal Contaminated Urban and Mining Areas in a Selected Missouri Superfund Site
EPA Grant Number: R831071Title: Environmental Risk Assessment of Phosphate-Based Remedial Technology in Metal Contaminated Urban and Mining Areas in a Selected Missouri Superfund Site
Investigators: Yang, John , Eivazi, Frieda , Campbell, Marjorie
Institution: Lincoln University-MO
EPA Project Officer: Hahn, Intaek
Project Period: October 1, 2003 through December 31, 2006 (Extended to October 31, 2007)
Project Period Covered by this Report: October 1, 2003 through December 31, 2004
Project Amount: $397,975
RFA: Superfund Minority Institutions Program: Hazardous Substance Research (2002) RFA Text | Recipients Lists
Research Category: Hazardous Waste/Remediation , Land and Waste Management , Safer Chemicals
Objective:
The objective of this research project is to determine whether the health risk reduction and stabilization of soil metals by in situ phosphate treatment are long-term, and whether the impact of the treatment on ecosystem is minimum through: (1) health and ecological assessments; (2) metal stability assessment; (3) chemical speciation; (4) microbial community assessment; and (5) long-term monitoring of water quality.
Progress Summary:
Three sets of samples, including soils (top and subsoil), plants, and waters (surface and ground water), have been collected from the plots of each treatment in the three identified field treatment sites in March, July, and October 2004. Twenty self-made lysiometers used to collect surface water samples were installed in the field on selected plots in March 2004. Our analytical efforts in 2004 were focused on in vitro bioavailability, microtoxicity, leachability, chemical fractionation, microbial diversity, water quality, and the simulated column leaching study. Chemical analyses of two out of three sets of the field samples have been completed.
Preliminary results have shown that phosphate or phosphate-rich biosolid treatments to contaminated soils effectively reduced in vitro lead (Pb) bioavailability and leachability regardless of soil matrixes (urban soil, mill wastes, or mining wastes), which potentially lowers Pb risk to human health and groundwater. The reductions increased with increasing amounts of added phosphate and reaction time. Transformation of exchangeable-Pb, carbonate-Pb, and Fe-Mn oxide-Pb to residual-Pb induced by treatment was primarily responsible for the Pb stabilization and health/ecological risk reduction. The transformation of soil Pb to less soluble species by treatments lowers soil toxicity to microorganisms, which substantially contributes to the enhancement of diversity and growth of the soil microbial community. Analyses of the surface and groundwater samples collected from the fields indicates that lower Pb concentrations were observed near the phosphate-treated areas, which was generally consistent with the result from the simulated column leaching study.
Future Activities:
We will complete chemical analyses and data processing of the samples collected in 2004. We will continue our efforts on sample collection and chemical analyses in 2005. Results of the comprehensive assessments will be incorporated into the final report.
Journal Articles:
No journal articles submitted with this report: View all 22 publications for this projectSupplemental Keywords:
soil metal contamination, phosphate treatment, in situ immobilization, risk assessment, superfund site, lead, remediation, health/ecological assessment, risk reduction, stability assessment, solid/chemical speciation, microbial community analyses, water quality, ecosystem, environmental impact, Missouri, MO, environmental science research program, soil science, soil chemistry, remedial process, cost-effective protection, chemical analysis, environmental toxicology, leachability, soil microbes,, RFA, Scientific Discipline, INTERNATIONAL COOPERATION, Waste, Water, Geographic Area, TREATMENT/CONTROL, POLLUTANTS/TOXICS, Waste Treatment, Contaminated Sediments, Environmental Chemistry, Remediation, State, Hazardous Waste, Soil Contaminants, Ecological Risk Assessment, Ecology and Ecosystems, Environmental Engineering, Hazardous, Superfund site remediation, phosphate treatment, hazardous waste treatment, risk assessment, sediment treatment, in situ remediation, metal stabilization, contaminated waste sites, bioavailability, contaminated sediment, lead, contaminated soil, ecological impacts, metals-contaminated soil, phosphate remedial technology, water quality, Missouri (MO), hazardous waste sites, heavy metal contamination, mining waste, metal contamination, mining wastes, metal remediationProgress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.