Superfund Innovative Technology Evaluation (SITE)
Note: EPA no longer updates this information, but it may be useful as a reference or resource.
|ZENON Environmental, Inc.Cross-Flow Pervaporation December 1998
The U.S. Environmental Protection Agency (EPA) has focused on policy, technical, and informational issues related to exploring and applying new technologies to Superfund site remediation. One EPA initiative to accelerate the development, demonstration, and use of innovative technologies for site remediation is the Superfund Innovative Technology Evaluation (SITE) Program. The SITE Program evaluated the ZENON Environmental, Inc. (ZENON), Cross-Flow Pervaporation technology, a membrane-based process that removes volatile organic compounds (VOC) from aqueous matrices. The ZENON technology provides an alternative approach to treating organic-contaminated water at sites where conventional treatment technologies are used, such as air stripping or carbon adsorption. A full-scale demonstration of the technology was performed during February 1995 at a former waste disposal area (Site 9) at Naval Air Station, North Island (NASNI), in Coronado, California. Groundwater at the site contains a variety of contaminants, mainly trichloroethene (TCE). The primary objectives of this demonstration were to (1) determine if the technology could remove TCE in groundwater to below the federal maximum contaminant levels (MCL) at varying flow rates, and (2) to determine the removal efficiency for TCE. A number of secondary objectives were also included in the demonstration, including the amount of TCE released from the technology to the outside air, the amount of concentrated waste (permeate) generated by the technology, and the costs associated with its use. To achieve the demonstration objectives, samples of untreated influent, treated effluent, and vapor were taken from the technology. Sampling and analytical procedures and quality assurance (QA) objectives for the demonstration were specified in an EPA-approved quality assurance project plan (QAPP). Lowering TCE concentrations to below MCLs may require multiple passes through the pervaporation module, which can prove impractical when compared to other technologies. The SITE evaluation demonstrated that the ZENON technology is best suited for reducing high concentrations of VOCs to levels that can be reduced further and more economically by conventional treatment technologies.