CICEET Progress Report for the period 9/01/01 through 3/01/02

Project Title: Phosphate-Based Heavy Metal Stabilization Technologies for Contaminated Sediments and Dredge Material
Principal Investigator(s): Dr. Taylor Eighmy, Bradley Crannell, Dr. Clinton Willson, Dr. Danny D. Reible, Ming Yin, Dr. Les Butler, Dr. Frank Cartledge

Accomplishments
Scheduled Tasks:

• Selection/collection of contaminated and clean sediments for pilot-scale project.
• Identification/collection of phosphate sources for research project.
• Establishment of the phase 1 pilot scale tank studies at the Jackson Estuarine Laboratories (JEL).
• Set-up of the Louisiana State University CAMD facility for x-ray fluorescence (XRF) analysis of diffusion tubes from the phase 1 pilot-scale study.

Progress on Tasks

• Uncontaminated sediments have been collected from the great-bay estuary, New Hampshire. Contaminated sediments will be collected from the Newtown Creek in New York, NY and the Anacostia River in Washington D.C. before the end of March.
• Two separate phosphate sources have been identified and collected for the research project. These are naturally occurring phosphate rock provided by IMC Agrico in Mulberry, Florida and a commercial product (Apatite II) which is a derivative of fish bones.
• The pilot-scale tank study is 80% constructed, and awaits the arrival of the contaminated sediments to be completed.
• Louisiana State University has completed setting up the CAMD facility for the XRF analysis. There is a new graduate student Ming Lin, he has been working on XANES and XAFS analysis with some samples from previous research. This will provide them with well established procedures prior to the arrival of more samples later this year.

Difficulties Encountered

• The original proposal called for a sediment source that was "naturally occurring", high in heavy metals, and low in organic pollutants. Because of the wide-spread nature of organic pollutants only one source for this material could be found in the New England area. Access to the site was denied by the site owners. After conferring with the project advisory board, it was decided to use a "real" sediment dredged from the east-coast region that contained both types of contaminants. Extra controls were added to phase 2 of the project, to account for the added biological stresses of the organic pollutants.
• The original acrylic tubes which were planned for use in the phase 1 tank studies became too brittle when shipped to Louisiana under dry ice. More flexible polyethylene tubes were used instead in the construction of these tanks to eliminate this problem.
• One of the selected phosphate sources known by it commercial name of Apatite II has a strong offensive odor when exposed to water. This has made use of large quantities of this material at the Jackson laboratories unmanageable. A different source of phosphate will be used for this portion of the research, although the Apatite II will be still feasible in the phase 2 and 3 experiments.

Anticipated Success in Meeting Project Objectives in Scheduled Project Period
The project is behind schedule. An hourly laborer is being hired to speed up construction and other aspects of the research. The research is progressing well and the project will still be completed on time.

Preliminary Results

• Four sediments were originally proposed for use in the pilot-scale research project. These are summarized in Table 1. These were selected based upon their heavy metal concentrations, organic contaminants, availability, and proposed dredging activities in the areas that might make them future test-plot locations.

  The Newtown Creek sediment was selected from among these options because of the high metal contaminant concentrations. The Anacostia River sediment was also selected for several of the experiments. The use of this later sediment will allow for overlap with a new research project being conducted at Louisiana State University. That research project will eventually lead to the establishment of several experimental capping systems along the length of the Anacostia River. This may be a good future application for the phosphate reactive barrier capping techniques. LSU is contributing to any additional expenses that may be incurred with the inclusion of the Anacostia river sediments.

  It was determined that only sediments collected from "real" contaminated locations should be used in the phase one experiments. In an effort to better understand the effects of the organic contaminants, several heavy metal spiked clean sediments will be used in addition to the contaminated sediments during phase 2 of the project..

• The LSU portion of this project primarily consists of utilizing and applying innovative laboratory methods to better understand the migration of heavy-metals through the sediments and barrier. The techniques include (i) the use of x-ray fluorescence (XRF) to monitor heavy-metal migration through a reactive material in both two and three dimensional models, (ii) the use of x-ray adsorption spectroscopy (XAS) to determine the nature of metal binding sites in contaminated sediments, and (iii) the use of Synchrotron x-ray microtomography (SXM) to observe changes in the pore structure of the sediment cores. LSU has completed setting up equipment and running trial scans to develop a methodology for the XRF and XAS analysis of the sediments as they age within the experimental tanks.
• Characterization of the phosphate sources has been under way, including both scanning electron microscopy (SEM), and x-ray powder diffraction (XRPD) analysis. Selected SEM images of both the phosphate sources are presented in Figures 1-4. The Apatite II material is derived from fish bones through a patented process. There are both crystalline and amorphous components to this phosphate material. Fish tend to have an amorphous structure to their bones, because of their growth in the ocean environment, and this is confirmed in the images. The amorphous nature of this material may greatly increase the reactivity of the calcium phosphate and therefore increase the ability of the material to bind heavy metals.

  Selected XRPD data for the Apatite II material is also presented in Figures 1-4. XRPD analysis only observes crystalline structures within the materials. The high signal to noise ratio is indicative of the amorphous nature of this material. Despite this high noise ratio, it is clear that the material consists primarily of fluoroapatite and hydroxyapatite minerals. For further analysis x-ray photoelectron spectroscopy (XPS) of the material will prove very useful, as it is not sensitive to the amorphous/ crystalline nature of the material.

• Construction details of the phase 1 tank study are presented in Figures 5-7. Tanks were constructed to allow for three types of sampling. In faunal colonization is being sampled in the 4 inch tubes. Pore water concentration profiles and changes in cap mineralogy are being monitored in the 2.5 inch tubes. Sediment concentration profiles are being monitored by LSU in the 1.5 inch tubes. The open side of the tanks are reserved for conducting 28-day polycheate tests at the conclusion of the study. Details of the different tank configurations are also presented in Figures 5-7. There are 5 basic categories of tanks being created. These include the 8 main test tanks in which the primary effects of the different capping materials will be analyzed. There are 6 control tanks, which will observe changes in and bioavailability of the clean capping materials in the absence of heavy metals. There are also 3 tanks which will receive filtered water, eliminating large scale in faunal colonization the effects of bioturbation. In a side experiment, two tanks are set up using geofabric impregnated with the different phosphate sources to determine the effects of this application technique. Finally, there is one monitoring tank, in which the incoming waters pH, Eh, salinity, conductivity, D.O. and temperature will be monitored.

Tasks and activities for next reporting period

Tasks for the next reporting period

• Complete analysis of all sediments and phosphate sources. Including elemental (NAA/XRF) and mineralogical (XRPD, XPS) analysis.
• Annual meeting with project advisory board
• Finished establishment of the phase 1 tank study at JEL
• Establishment of the phase 2 and 3 studies at UNH
• Base-line analysis of phase 1 diffusion profiles at LSU

Work plan to accomplish tasks

• Elemental analysis of sediments and phosphates will be outsourced, while mineralogical analysis will be conducted in house.
• The annual advisory board meeting will be held in July at a time that is amenable to all interested parties.
• The collection of sediments from New York and Washington D.C. is being conducted during the final weeks of March. With these sediments, the construction of the tanks at JEL will be able to be completed
• After the construction of the phase 1 tank study is completed, the smaller, phase 2 and 3 studies will be established.
• LSU has already been setting up the beam lines, and preparing for the analysis of cores taken from the phase 1 tank studies. A set of day 30- tubes will be analyzed by LSU to mark a baseline for the tanks, after equilibrium has been established.

Concerns or difficulties
Anticipated difficulties during this reporting period are primarily related to catching up from being behind schedule. This will be accomplished through the use of additional personnel on the project.

Expenditures
Overall expenditures have been within the anticipated range for work accomplished to date. Additional finances were made available due to an indirect cost miscalculation which the University of New Hampshire made. Extra costs were incurred to collect the sediments from New York, as only a large ship was available for the task.