Superfund Research Program

Technology Demonstration Core

Project Leader: A. Jay Gandolfi
Grant Number: P42ES004940
Funding Period: 2000 - 2005

Project-Specific Links

Final Progress Reports

Year:   2004 

This core recognizes that translation of laboratory studies to the field is mandatory. The field studies are addressing the two common hazardous wastes are present in the majority of the contaminated sites in Arizona:
1. Arsenic (in water or in mine tailings).
2. Halogenated solvents (from dry cleaning and degreasing operations) - primarily  trichloroethylene and perchloroethylene.

The field studies were:
A. Using Mathematical Models to Evaluate Feasibility of Monitored Natural Attenuation for Remediation of Chlorinated-Solvent Contaminated Sites in AZ: Preliminary Assessment (Mark L. Brusseau)

The objective of this work is to conduct a preliminary assessment of using mathematical modeling to evaluate the potential success of applying MNA to chlorinated-solvent contaminated sites in Arizona. The work is focused on using information from the Park/Euclid WQARF site in Tucson.

B. Microbial Mobilization of Arsenic from Landfills (James A. Field)

This project examines the role microbial transformations will play in determining the fate of sorbed arsenic in landfills. Dissimilatory reduction of arsenate (As(V)) to the more mobile and toxic arsenite (As(III)) species, and reductive dissolution of ferric sorbents are known to occur in anaerobic environments. These microbial processes could increase the mobility of arsenic in landfills.

C. Revegetation of the San Pedro River Mine Tailings Site Using Native Salt- and Drought-
Tolerant Plants (Raina M. Maier)

A field trial was initiated at the San Pedro River Mine Tailings Site to determine whether re-vegetation with native plant species could stabilize the mine tailings so that erosion processes would be reduced or eliminated completely.  The site is being monitored for the following parameters: metal content in the tailings and in the plant root and shoot tissues, microbial counts and diversity analysis, and plant root and shoot biomass.

D. Development and Implementation of Leaching Assessment Protocol for Oxyanions
(Wendell P. Ela)

The project objective is to develop, validate, and field test a protocol for predicting leaching of hazardous oxyanions from sludge and solid wastes. The initial effort is focusing on arsenate as a representative toxic oxyanion and on residuals from water treatment operations for arsenic removal as the toxic bearing wastes. The assessment protocol being developed will provide a tractable, short-term, robust procedure to predict the maximum mass of oxyanion release from a residual and consequently guide the choice of an appropriate, benign disposal option.

E. Field Test of an Electrochemical Reactor for the Destruction of Chlorinated Hydrocarbons
(Eduardo Saez)

The objective of this project is the examination and implementation of a cost-effective alternative technique for field scale treatment of sites contaminated with hazardous semi-volatile chlorinated solvents. Using a gas diffusion membrane-electrode assembly with a modified fuel cell reactor, contaminants will be converted to non-halogenated, nontoxic products. The removal of solvents from soil vapor in the vadose zone may be cheaper and produce no toxic byproducts compared to methods currently in use.