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ITAN-16-1996 15:20 REGENESIS <br /> P.06 <br /> Ems <br /> in the early development of bioremedlation formulations of ORO, several independent laboratories and universities <br /> participated in proof-of-concept studies indicating that ORO releases oxygen, <br /> promotes remediation. Subsequently, field applications demonstrated that ORC wasseff ctivbeain ptrolmoting <br /> bioremediation under'real world'conditions. <br /> a University of Waterloo (published, Groundwater Monitoring and Remediation, Winter 1994) — Conducted at the <br /> widely studied Borden Aquifer in Ontario, Canada, the study indicates that an Oxygen Barrier generated by ORO <br /> released significant amounts of dissolved oxygen (DO). It concluded that the enhancement of DO by ORO led to the <br /> biodegradation of at least 4 mg/I_each of benzene and toluene. <br /> ■ North Carolina Site (published, Proceedings from the Second International Symposium on In Situ and On-Site <br /> Blo=lamation, San Diego, CA, 1993) — This study demonstrated that the use of ORO in an Oxygen Barrier <br /> dramatically reduced BTEX Compounds downgradient from a UST generated gasoline spill. <br /> r, Alaska Site (presented at the I&EC Special Symposium, American Chemical Society, Atlanta, GA, 1995) — A pilot <br /> study showed the effectiveness of an ORO remediatlOn compared to air sparging. Sparge points fouled in the high <br /> iron environment and there was evidence of channeling — a problem common with this technology. ORC was <br /> effective in remediation and a full barrier was installed. Benzene levels were reduced from 320 ppb t0 9.8 ppb and <br /> total BTEX went from 1361 ppb to 17 ppb. Gasoline range organics went to NO (not detected) from 7.4 ppm. Diesel <br /> range organics rose from ND to .55 ppm, indicating there may have been an influx of hydrocarbons during the test. <br /> n New Mexico Site (presented at The New Mexico Environment Department UST Bureau Bioremediation Conference, <br /> Santa Fe, NM 1995) —At this site, ORC was installed in 20 wells to form an Oxygen Barrier. There was a high <br /> contaminant flux at the site (5-15 ppm at 1-2 feet per day). DO increased from inadequate levels and was <br /> maintained at 10 ppm and greater for the first 30 days. After 93 days the estimates of the remaining oxygen <br /> indicated that a change out of ORC would not be required for six months. During this 93 day period, a significant <br /> reduction of BTEX mass was achieved in the treatment zone, such that concentrations of total BTEX in samples <br /> from the most downgradient well (measured at 120 feet from the barrier) declined to ND. At this well, assays of <br /> aerobic microbial degraders were two orders of magnitude higher than background,thus indicating the presence of <br /> oxygen from the ORO installation was driving bioremediation. <br /> ® 16-Site OAC Performance Evaluation—ORC was placed in 41 existing wells on 16 sites and monitored for a 7 to 12 <br /> week period. The average dissolved oxygen levels were significantly increased; two-thirds of the readings were <br /> between 20 and 30 ppm, even while in the presence of dissolved phase BTEX. As expected, the BTEX levels dropped <br /> dramatically-between 80 and 100 percent in 75%of the wells-a third of those being fully remediated (see Figure 4). <br /> 16-SITE ORC PERFORMANCE EVALUATION <br /> Average DO Increase(41 Wells) <br /> Average BTEX Degradation(41 Wells) <br /> l <br /> .`^\i 1 44^n` <br /> asy al�i>,x fns '�'. <. �..: e LI�RL. tom: <br /> L T � ; b {b a'b b� � YL �� w•:•Q N 5 i d , <br /> � ¢ i6rAh '•-i. A a2r"�.r ww mx w.< 5� �� to 3 xs..��v <br /> 1s <br /> 4.020 <br /> is <br /> 0 0000 , gORUpU {7l °` `i�E�.'3 <br /> 1 £�^ .n <br /> •" d<, 'R" '31 '� aF')RaY e M -+ , �` ;E es �! ''Ea ,, <br /> Y y. <br /> CURRENT.% <br /> 771 v <br /> AVERAGE GO <br /> AVERAGE BTEX <br /> figure 4 these graphs illustrate the results or the 16-0e ORC Performance Evaluatlon program described above. <br /> 13PIge <br />