Superfund Innovative Technology Evaluation (SITE)
Note: EPA no longer updates this information, but it may be useful as a reference or resource.
E.I. DuPont De Nemours &
Company/Oberlin Filter Company Microfiltration Technology Applications
Analysis Report (PDF) (61 pp, 2.03 MB) ()
This report evaluates the DuPont/Oberlin microfiltration technology's ability to remove metals (present in soluble or insoluble form) and particulates from liquid wastes while producing a dry filter cake and a filtrate that meet applicable disposal requirements. This report also presents economic data from the Superfund Innovative Technology Evaluation (SITE) demonstration and, as available, three case studies.The DuPont/Oberlin microfiltration technology combines Oberlin's automatic pressure filter with DuPont's new microporous Tyvek® filter media. It is designed to remove particles that are 0.1 micron in diameter, or larger, from liquid wastes, such as contaminated groundwater. Groundwater with dissolved metals must first be treated to convert the dissolved metals into an insoluble form prior to microfiltration.
The DuPont/Oberlin microfiltration technology demonstration was conducted under the SITE program at the Palmerton Zinc Superfund site in Palmerton, Pennsylvania, in April and May 1990. During the demonstration, the microfiltration system achieved zinc and total suspended solids (TSS) removal efficiencies of about 99.95 percent, and a filter cake solids content of 41 percent. The filter cake contained no free liquids, and a composite sample from all the demonstration runs passed both the extraction procedure toxicity test and the toxicity characteristic leaching procedure (TCLP) test. The filtrate met applicable National Pollutant Discharge Elimination System permit limits for metals and TSS but not for pH; the filtrate pH was typically 11.5 while the upper pH limit is 9.
The results from three case studies are also summarized in this report. All three facilities treated process wastewaters containing metals and TSS ranging from several parts per million to several percent. The filtrates at all three facilities met their respective discharge limits. Filter cake at one facility is a mixed waste and is further stabilized and solidified with cement prior to land disposal. At another facility, filter cake did not pass the TCLP test and is considered a hazardous waste. No filter cake information was available from the third facility.
Possible sites for applying this technology include Superfund and other hazardous waste sites that have groundwater and
other liquid wastes contaminated primarily with metals and particulates. Sources of metal-bearing wastes include electroplating
and metal finishing facilities, electronic component manufacturers, aluminum and other metal forming facilities, and
uranium processing facilities. Economic data indicate that the capital costs for only the microfiltration unit and ancillary
equipment are $48,000 for a 2.4-square foot unit and about $232,000 for a 36-square foot unit. Annual operation and maintenance
(O&M) costs (including analytical, labor, and disposal costs) are estimated to be about $213,000 for the smaller unit
and $549,100 for the larger unit, with corresponding annual throughputs of 525,600 gallons and 7,884,000 gallons.
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