Grantee Research Project Results
2005 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, 2004 through December 31, 2005
Project Amount: $397,975
RFA: Superfund Minority Institutions Program: Hazardous Substance Research (2002) RFA Text | Recipients Lists
Research Category: Hazardous Waste/Remediation , Safer Chemicals , Land and Waste Management
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 nearly permanent, and whether the phosphate treatments are environmentally safe through: (1) health and ecological assessments; (2) metal stability assessment; (3) determination of 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 groundwater), have been collected from the treatment plots of the residential, milling, and mine waste sites, respectively, located in the Jasper County Superfund Site, southwest Missouri, in March, June, and September 2005. Microbial analyses, including biomass, diversity, and enzyme activity, are nearly complete, and data analyses are in progress. Chemical analyses, including in vitro bioavailability, microtoxicity, leachability, chemical speciation, and water quality, are completed on four out of six sets of the collected samples. A greenhouse study on column leaching under simulated conditions is in progress.
Preliminary data show that the phosphate treatment had reduced effectively in vitro Pb bioavailability and leachability in contaminated soil and mine wastes, which potentially lowers health and ecological risks from Pb exposure. The risk reduction was accomplished by transforming labile Pb species to less soluble forms induced by soil treatment. Increased residual Pb forms and decreased exchangeable and carbonate Pb fractions primarily were responsible for the risk reduction. Treatment effects on metal immobilization varied with phosphate sources and application methods and were dependent on soluble phosphate levels in soil. Data of microbial analyses indicate that the in situ phosphate soil treatment has no negative impacts on microbial community in treated soils. The similarity in microbial biomass, as measured by total organic carbon and total nitrogen, and in phosphatase activity was observed for both the treated and untreated soils. The presence of common bands in denaturing detergent gradient gel electrophoresis patterns across treatments suggested that phosphate treatment has a limited effect on soil bacterial diversity. The phosphate treatment was found to significantly lower soil toxicity to microorganisms, which may be attributed to reduced soluble Pb concentrations resulting from the transformation of soil Pb to less soluble species induced by the soil treatments. Results currently support our hypothesis that the Pb risk reductions in soil by in situ phosphate treatments would be long-term, and the soil treatments are environmentally safe in the context of microbial growth and diversity.
Future Activities:
We plan to collect one more set of field samples in early 2006 when weather permits. Microbial measurements data currently are being analyzed and are scheduled to be completed in May 2006. Our efforts in the next year will focus on completing chemical analyses of all collected field samples before the summer of 2006 and starting data processing in the fall. The final project report is scheduled to be completed in December 2006.
Journal Articles on this Report : 1 Displayed | Download in RIS Format
| Other project views: | All 22 publications | 3 publications in selected types | All 3 journal articles |
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Yang J, Mosby D. Field assessment of treatment efficacy by three methods of phosphoric acid application in lead-contaminated urban soil. Science of The Total Environment 2006;366(1):136-142. |
R831071 (2005) R831071 (2006) |
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Supplemental Keywords:
superfund site, Missouri, MO, soil lead/zinc contamination, health and ecological risks, in situ immobilization, phosphate treatment, pyromorphite, risk reduction, lead, remediation, in vitro bioavailability, plant metal uptake, metal stability/leachability, solid/chemical speciation, soil microtoxicity, microbial biomass, microbial diversity, enzyme activity, surface/groundwater quality, ecosystem, environmental quality, soil treatment impact, soil chemistry, soil remedial process, cost-effective/environmental-safe protection,, RFA, Scientific Discipline, INTERNATIONAL COOPERATION, TREATMENT/CONTROL, Geographic Area, Waste, Water, POLLUTANTS/TOXICS, Hazardous, Remediation, Ecological Risk Assessment, Waste Treatment, State, Environmental Chemistry, Contaminated Sediments, Hazardous Waste, Ecology and Ecosystems, Environmental Engineering, Soil Contaminants, bioavailability, metal stabilization, Superfund site remediation, contaminated sediment, lead, metal contamination, sediment treatment, water quality, Missouri (MO), hazardous waste treatment, mining wastes, risk assessment, metal remediation, contaminated soil, metals-contaminated soil, in situ remediation, phosphate treatment, phosphate remedial technology, hazardous waste sites, mining waste, heavy metal contamination, contaminated waste sites, ecological impactsProgress 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.