Grantee Research Project Results
2006 Progress Report: Reactive Metal Particle Emulsions for Removal of PCBs
EPA Grant Number: X832302C003Subproject: this is subproject number 003 , established and managed by the Center Director under grant X832302
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
Center: Center for Science and Policy Applications for Coastal Environments (CSPACE)
Center Director: D'Elia, Christopher F
Title: Reactive Metal Particle Emulsions for Removal of PCBs
Investigators: Carvalho-Knighton, Kathy , Geiger, Cherie , Clausen, Christian
Institution: University of South Florida
EPA Project Officer: Packard, Benjamin H
Project Period: September 1, 2005 through August 31, 2008
Project Period Covered by this Report: September 1, 2005 through August 31, 2006
RFA: Targeted Research Center (2004) Recipients Lists
Research Category: Hazardous Waste/Remediation , Targeted Research
Objective:
Polychlorinated biphenyls (PCBs), along with polyaromatic hydrocarbons (PAHs) and organochlorine pesticides, are contaminants in the Tampa Bay area that have been monitored since 1993. Four locations in the Tampa Bay have been significantly studied including the lower Hillsborough River, the Palm River, the Alfia River, and the Little Manatee River. PCBs have been detected in extremely high concentrations in the Palm River, moderate to high concentrations in the Hillsborough River, and low to moderate concentrations in portions of upper Hillsborough Bay. Based on the areas already affected by PCBs additional work must be done in areas of the Ybor channel and the Seddon Channel. Storm water runoff and landfill leaching are considered to be likely sources of PCBs in the Tampa Bay area. PCB sediment contamination in Tampa Bay has led to morphological and histochemical changes in fish and increased defense mechanisms in oysters. Since the high levels of PCBs in the Tampa Bay area are of concern, there is a need for a low cost, effective remediation technique. This project seeks to develop the necessary technique for in situ remediation of PCBs in the Palm River.
Progress Summary:
The project is proceeding as planned and has the participation of many enthusiastic and strongly motivated students from the University of South Florida (USF) and the University of Central Florida (UCF). Task 1 was to obtain reagents and supplies and begin feasibility studies. Aroclor 1254 standards and individual PCB congeners have been purchased. An emulsion consisting of Pd/Mg bimetal, oil, water, and sorbitan trioleate (SPAN 85) was tested with Aroclor 1254. Degradation was slow (> 10% in a week)—a possible explanation may be that PCBs remain in oil layer and are not diffusing into water layer to react with metal, so the researchers began formulating other possible emulsions. Task 2 was to continue feasibility studies and perform kinetic studies. Several different emulsion formulas have been tested. Emulsions consisting of varying amounts of Pd/Mg bimetal, ethanol, water, and SPAN 85 were not stable . Emulsions consisting of varying amounts of Pd/Mg bimetal, methanol, water, and SPAN 85 were not stable. Current emulsions being tested consist of Pd/Mg bimetal, methanol, water, and Triton X-100, a surfactant proven successful in PCB soil remediation. Kinetic studies have been focused on several individual congeners with neat Pd/Mg. PCB 77 was chosen because of the high TEF (toxicity equivalent factor) value. PCB 52, 61, 62, 65, 70, and 80 were examined for structural reasons and to compare to PCB 77. PCB 93, 95 (pentachlorobiphenyls), and PCB 151, 153 (hexachlorobiphenyls) were examined and by-products were identified. Kinetics indicate a pseudo first order reaction and rate constants have been determined for all of the above congeners. The mechanism appears to be step-wise with biphenyl as the final product. In all congener studies, reaction with Pd/Mg is slow for the first 30 minutes, with rapid dechlorination between 30–50 minutes, and then levels off. Current studies are focusing on different solvent systems and lower chlorinated PCBs to elucidate the mechanism.
Supplemental Keywords:
water, watersheds, groundwater, land, soil, marine, estuary, chemicals, toxics, PCB, heavy metals, ecosystem, restoration, terrestrial, aquatic, habitat, innovative technology, remediation, restoration, public policy, decision making, modeling, monitoring, analytical, remote sensing, Florida, FL, EPA Region 4, social science, Florida (FL), Phosphate rock mining (SIC 1475), water, orthophosphate, total phosphorus, Tampa Bay, Bishops Harbor, Cockroach Bay, sediment, pore water.,, RFA, Scientific Discipline, Water, Water & Watershed, Wastewater, Environmental Monitoring, Ecology and Ecosystems, Watersheds, coastal watershed, nutrient flux, PCBs, hazardous waste, remediation, PAHs, aquatic ecosystems, coastal ecosystems, water qualityRelevant Websites:
http://www.stpt.usf.edu/cspace/cspace.asp Exit
Progress and Final Reports:
Original AbstractMain Center Abstract and Reports:
X832302 Center for Science and Policy Applications for Coastal Environments (CSPACE) Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
X832302C001 Past and Present Water Quality in Florida Coastal Waters
X832302C002 Cyanobacteria Proliferation and Eutrophication in Florida Lakes
X832302C003 Reactive Metal Particle Emulsions for Removal of PCBs
X832302C004 The Social and Environmental Dimensions of Xeriscaping: A Pathway for Ameliorating Coastal Environments
X832302C005 An Historical Perspective on the Economic and Environmental Impacts of the Phosphate Industry on the Tampa Bay Region
X832302C006 Interfacing SWAT and PHABSIM: A Potential GIS-based Water Resource Management Tool
X832302C007 Acquisition of Counters for Gamma-Emitting Radioisotopes
X832302C008 Guided Surface Vehicles
X832302C009 Science Journalism
X832302C010 Administration and Outreach
The 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.