Grantee Research Project Results

Final Report: Solubilization of Particulate-Bound Ni(II) and Zn(II)

EPA Grant Number: R828771C012
Subproject: this is subproject number 012 , established and managed by the Center Director under grant R828771
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
Center: Center for the Study of Childhood Asthma in the Urban Environment
Center Director: Hansel, Nadia
Title: Solubilization of Particulate-Bound Ni(II) and Zn(II)
Investigators: Stone, Alan T.
Institution: The Johns Hopkins University
EPA Project Officer: Aja, Hayley
Project Period: October 1, 2001 through September 30, 2007
RFA: Hazardous Substance Research Centers - HSRC (2001) Recipients Lists
Research Category: Hazardous Waste/Remediation , Land and Waste Management

Objective:

Solubilization of Particulate-Bound Ni(II) and Zn(II). Alan Stone (JHU). Models currently used to characterize metal-contaminated sites have three principal shortcomings. First, toxic metal speciation in many instances is under kinetic control rather than thermodynamic control. Second, host solids are often reworked by precipitation/dissolution reactions such that toxic metal ions become physically inaccessible. Finally, soil organic matter constituents are difficult to characterize and hence difficult to properly consider in quantitative models. In order to more accurately model toxic metals in contaminated sites, we need to understand: (1) when the speciation of toxic metals is under kinetic control and not thermodynamic control, (2) how the structure of a chelating agent affects the rate of coordination reactions, and (3) what synergistic (or catalytic) reactions may occur when multiple chelating agents and surfaces are present. The goals of this research project were to (1) use nickel as a model toxic metal under kinetic control, (2) develop analytical methods for measuring nickel speciation using capillary electrophoresis (CE), (3) develop structure-activity relationships for nickel desorption and exchange reactions and (4) explore possible synergistic effects with surfaces and multiple chelating agents.

Summary/Accomplishments (Outputs/Outcomes):

Experiments examined the dissolution of Ni(OH)₂(s) and the desorption of Ni(II) and Zn(II) from FeOOH (goethite) and Fe(OH)₃ (ferrihydrite) surfaces. Capillary electrophoresis (CE) was used to monitor processes taking place in aqueous solutions, and high resolution transmission electron microscopy (HRTEM) was used to assess surface structural changes. Several sets of experiments were devoted to the synthesis of Ni(OH)₂(s) and FeOOH(goethite) particles. Additional experiments refined the analytical techniques (CE-based methods) for discerning the aqueous speciation of Ni(II) and Fe(III). The results show that desorption of Ni from TiO2 is fast. Desorption of Ni from Fe₂O₃ (hematite) is slow. This makes Fe₂O₃ a suitable surface for comparing the kinetics of Ni desorption by different chelating agents.

One project addressed transport and fate issues for organic contaminants in the subsurface in order to provide input on exposure pathways from contaminated groundwaters and soils. The research also involved reaction processes that are important in natural attenuation of contaminants. This project also contributed to risk management issues.

Journal Articles:

No journal articles submitted with this report: View all 1 publications for this subproject

Supplemental Keywords:

air quality, groundwater contamination, organics, metals, hyporheic zone, TOSC, TAB, outreach projects, Brownfields,, RFA, Scientific Discipline, INTERNATIONAL COOPERATION, Waste, POLLUTANTS/TOXICS, Hazardous, Ecological Risk Assessment, Environmental Chemistry, Hazardous Waste, Chemicals, Environmental Engineering, heavy metals, hazardous waste disposal, hazardous waste management, hazardous waste treatment, Zinc, contaminated waste sites, hazardous waste characterization, chemical releases, capillary electrophoresis

Relevant Websites:

Center for Hazardous Substances in Urban Environments http://www.jhu.edu/hsrc/index.htm Exit

Progress and Final Reports:

Original Abstract

Main Center Abstract and Reports:

R828771 Center for the Study of Childhood Asthma in the Urban Environment

Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
R828771C001 Co-Contaminant Effects on Risk Assessment and Remediation Activities Involving Urban Sediments and Soils: Phase II
R828771C002 The Fate and Potential Bioavailability of Airborne Urban Contaminants
R828771C003 Geochemistry, Biochemistry, and Surface/Groundwater Interactions for As, Cr, Ni, Zn, and Cd with Applications to Contaminated Waterfronts
R828771C004 Large Eddy Simulation of Dispersion in Urban Areas
R828771C005 Speciation of chromium in environmental media using capillary electrophoresis with multiple wavlength UV/visible detection
R828771C006 Zero-Valent Metal Treatment of Halogenated Vapor-Phase Contaminants in SVE Offgas
R828771C007 The Center for Hazardous Substances in Urban Environments (CHSUE) Outreach Program
R828771C008 New Jersey Institute of Technology Outreach Program for EPA Region II
R828771C009 Urban Environmental Issues: Hartford Technology Transfer and Outreach
R828771C010 University of Maryland Outreach Component
R828771C011 Environmental Assessment and GIS System Development of Brownfield Sites in Baltimore
R828771C012 Solubilization of Particulate-Bound Ni(II) and Zn(II)
R828771C013 Seasonal Controls of Arsenic Transport Across the Groundwater-Surface Water Interface at a Closed Landfill Site
R828771C014 Research Needs in the EPA Regions Covered by the Center for Hazardous Substances in Urban Environments
R828771C015 Transport of Hazardous Substances Between Brownfields and the Surrounding Urban Atmosphere

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