&EPA United States Office of Solid Waste and Emergency Response Environmental Protection Office of Research and Development Agency Washington, DC 20460 August 1995 PROGRAM FACT SHEET Demonstration of the Matrix Photocatalytic Inc. Photocatalytic Oxidation Technology THIS FACT SHEET TELLS YOU ABOUT ¦ EPA's Superfund Innovative Technology Evaluation (SITE) Program ¦ An EPA SITE Program demonstration of an innovative photocatalytic oxidation technology ¦ A Visitors' Day on September 7, 1995, at 9:30 a.m. at the DOE Oak Ridge Reservation in Oak Ridge, Tennessee Introduction The U.S. Environmental Protection Agency (EPA) identifies new methods for hazardous waste cleanup through its Superfund Innovative Technology Evaluation (SITE) Program. Created in 1986, this program evaluates innovative treatment technologies that may significantly reduce the toxicity, mobility, or volume of hazardous wastes. The primary goal of the SITE Program is to generate performance, cost, and reliability information on innovative technologies. This information can then be used to evaluate cleanup alternatives for similar sites. One technology to be demonstrated under the SITE Program is the photocatalytic oxidation technology developed by Matrix Photocatalytic Inc. (Matrix), of London, Ontario, Canada. The demonstration will take place at the Department of Energy (DOE) Oak Ridge Reservation (ORR) in Oak Ridge, Tennessee. A primary objective of the demonstration is to determine how effectively the technology destroys volatile organic compounds (VOC) in groundwater at the K-25 Site at ORR. This fact sheet presents a brief discussion of the SITE Program, the Matrix technology, the K-25 Site, the Matrix technology demonstration, and the Visitors' Day at the K-25 Site. The SITE Program Each year, EPA solicits proposals from private technology developers to demonstrate innovative technologies under the SITE Program. For each technology selected, EPA performs the following tasks, often with input from state and regional environmental protection agencies: • Identifies a site with wastes suitable to demonstrate the technology • Prepares a quality assurance project plan (QAPP) and a health and safety plan for the demonstration • Prepares a fact sheet for the public • Conducts the technology demonstration • Conducts and audits field sampling and laboratory analyses • Organizes a Visitors' Day for the public to view the technology demonstration • Evaluates technology performance and costs • Summarizes demonstration results in a demonstration bulletin, a technology capsule, an innovative technology evaluation report (ITER), a technology evaluation report (TER), and a videotape Technology Description The Matrix photocatalytic oxidation technology destroys VOCs in aqueous systems at ambient temperatures. This technology involves the use of ultraviolet (UV) light, a semiconductor catalyst (titanium oxide [Ti02]), hydrogen peroxide, and ozone to generate hydroxyl radicals. 1 ------- The main component of the Matrix system is the photocatalytic reactor cell, shown in Figure 1. The reactor cell consists of an outer stainless-steel jacket that encases a fiberglass mesh bonded with TiOr This fiberglass mesh is wrapped around a quartz sleeve that houses the UV lamp. The lamp emits low-intensity UV light (predominantly at 254 nanometers [nm]) and is mounted coaxially within the jacket. Contaminated water flows into the reactor cell and passes through the fiberglass mesh, where the contaminants are oxidized. As the water passes through the matrix, the open pore configuration of the mesh creates turbulent mixing, thereby improving mass transfer in the mesh. The reactor cells can be operated in series or in parallel, depending on the concentration of contaminants, the required throughput rate, and the amount of organic destruction desired. The system can be operated in either continuous flow or batch mode. Matrix claims that the technology does not generate residue, sludge, or spent media that require further processing, handling, or disposal. Target VOCs are either completely oxidized or broken down into low molecular weight compounds. Hydrogen peroxide or ozone may be added to the contaminated water to enhance system performance. These compounds cause additional hydroxyl radicals to be generated when the contaminated water reacts-with the UV- light in the presence of the Ti02. If the amount of hydroxyl radicals is insufficient, contaminants may not be completely degraded and unstable intermediate compounds may form. Some of these intermediate compounds, such as haloacetic acids and aldehydes, are considered toxic. The system to be demonstrated at ORR will consist of two units operated in series. Each unit consists of 72 reactor cells arranged into 12 wafers. Each wafer consists of six reactor cells (see Figure 2). Contaminated groundwater will flow in parallel mode into three reactor cells at a time at a maximum flow rate of 2.4 gallons per minute (gpm). Site Description The K-25 Site at ORR was chosen for the demonstration (see Figure 3). The K-25 Site consists of 1,700 acres, 700 of which are enclosed in security fencing in the northwest corner of ORR. The main plant at the K-25 Site was built between 1943 and 1945 as part of the Manhattan Project and was used to develop uranium-enriched materials for nuclear weapons. During the postwar period, the plant was used to produce enriched uranium for reactors used to generate electric power. The demonstration will take place near a 22-acre, inactive burial ground on the east side of the K-25 Site. This burial ground consists of the K-1070C and K-1070D burial system ounrr Figure 1. Matrix Photocatalytic Reactor Cell grounds. The K-1070C burial ground operated until 1974 and the K-1070D burial ground operated from 1974 until 1989. These areas were used for the disposal of various hazardous wastes, including solvents, corrosives, oxidizers,., reducing agents., and .classified material. A Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) remedial investigation has been ongoing at the burial ground since 1993. During the demonstration, the Matrix system will treat groundwater from the SW-31 spring located west of the burial ground. Groundwater samples from this spring have contained elevated concentrations of VOCs, including xylene at 330 micrograms per liter (/ig/L), 1,1,1-trichloroethane at 930 Hg/L, and 1,1-dichloroethane at 910 fig/L. EPA will evaluate the removal efficiencies achieved by the Matrix system for these and other VOCs. Technology Demonstration EPA will evaluate the Matrix photocatalytic oxidation technology during a 2-week demonstration. Groundwater from spring SW-31 has high concentrations of iron and manganese (16 and 9.9 milligrams per liter [mg/L], respectively). Metals present in water can form a precipitate on the quartz sleeve or fiberglass mesh, causing scaling. Therefore, a pretreatment system consisting of two parallel cartridge filters and several ion-exchange columns will be used to reduce the concentrations of these metals in the groundwater. After pretreatment, the groundwater will be injected with a spiking solution containing tetrachloroethene, trichloroethene, and benzene. These compounds were selected as spiking agents because they are common 2 ------- WAFER 11 WAFER 9 WAFER 7 WAFER 5 WAFER 3 WAFER 1 -SYSTOJ fNlET STAM&SS steel -SSSU&ffltEL Figure 2. Matrix Unit and Wafer Configuration Diagram groundwater contaminants but are not present in significant concentrations in groundwater from the SW-31 spring. Hydrogen peroxide and ozone will also be added to the Matrix system at selected locations to enhance the generation of hydroxyl radicals. The Matrix system will be housed in an 8-by-20-foot, secure trailer. Treated water will be returned to the SW-31 spring for eventual discharge to the on-site groundwater treatment facility. EPA has prepared a detailed QAPP outlining the procedures for evaluating the technology. The purpose of the demonstration is to obtain performance, cost, and reliability data about the Matrix technology so that potential users can judge the technology's applicability to other sites. After the demonstration is complete, EPA will publish the results in several reports. Preliminary information on the Matrix technology's performance, cost, and reliability will be summarized in a demonstration bulletin. A more detailed account of the technology's performance and applicability will be presented in a technology capsule, an ITER, a TER, and a videotape. Visitors' Day EPA and DOE will host a Visitors' Day on Thursday, September 7, 1995. The Visitors' Day will include presentations about the EPA SITE Program, the ORR K-25 Site, the Matrix photocatalytic oxidation technology, and the demonstration. Visitors will also be able to view the technology demonstration activities at the K-25 Site. Those interested in attending the Visitors' Day should complete and return the enclosed preregistration form or call Kelly Enwright at (513) 241-0149. All forms must be received by Wednesday, August 30, 1995. Additional Information Questions or comments about the SITE Program or the demonstration should be directed to: Mr. Richard Eilers Technical Project Manager U.S. Environmental Protection Agency National Risk Management Research Laboratory 26 West Martin Luther King Drive Cincinnati, OH 45268 Telephone:(513) 569-7809 3 ------- Specific questions about ORR or the K-25 Site should be directed to: Ms. Elizabeth Phillips U.S. Department of Energy 3 Main Street Oak Ridge, TN 37830 Telephone:(615) 241-6172 Specific question about the Matrix photocatalytic oxidation technology should be directed to: Mr. Bob Henderson Matrix Photocatalytic Inc. 22 Pegler Street London, Ontario, Canada N5Z 2B5 Telephone:^ 19) 660-8669 $ EPA U.S. Environmental Protection Agency 26 West Martin Luther King Drive, MS-445 Cincinnati, Ohio 45268 Attention: Richard Eilers ------- |