HR: 1340h
AN: H23A-1410    [Abstracts]
TI: Field Demonstration of Sequential Iron Reduction and Aerobic Biodegradation of Nitrobenzene and 2,4-Dinitrotoluene
AU: * Robinson, T L
EM: tl2robin@uwaterloo.ca
AF: University of Waterloo, Department of Earth Sciences 200 University Ave W, Waterloo, ON N2L 3G1 Canada
AU: Gillham, R W
EM: rwgillha@sciborg.uwaterloo.ca
AF: University of Waterloo, Department of Earth Sciences 200 University Ave W, Waterloo, ON N2L 3G1 Canada
AU: Gui, L
EM: lgui@sciborg.uwaterloo.ca
AF: University of Waterloo, Department of Earth Sciences 200 University Ave W, Waterloo, ON N2L 3G1 Canada
AB: To demonstrate the in situ sequential degradation of nitrobenzene (NB) and 2,4-dinitrotoluene (2,4-DNT) using a granular iron permeable reactive barrier (PRB) and aerobic biodegradation zone, a field study is currently being conducted in a 24m long x 2m wide x 3m deep isolated section of the Borden aquifer (the ``gate''). This gate is closed on three sides by sealable-joint sheet piling keyed into the aquitard, and open to groundwater flow on the other, which, under natural conditions, is approximately parallel to the longest sides of the gate. The PRB was installed approximately 10 meters into the gate, and the oxygen injection system was installed approximately 18 meters into the gate. A hydraulic gradient was induced across the gate by pumping at the closed end via a fully-screened well, resulting in a groundwater velocity of 40-50 cm/day. Based on the results of laboratory tests, the first stage of the treatment system, involving the PRB, was expected to reduce nitrobenzene and 2,4-DNT to aniline and 2,4-diaminotoluene (2,4-DAT), respectively. Initial results show that portions of the nitrobenzene and 2,4-dinitrotoluene were transforming into their daughter products, aniline and 2,4-diaminotoluene, prior to the groundwater entering the permeable reactive barrier. Lab tests are ongoing to determine whether an indigenous bacterial population is capable of biotically transforming the nitro groups on the nitrobenzene and 2,4-DNT. In the second stage of the treatment system, oxygen was introduced via 4 10-inch diameter fully-screened wells spanning the width of the gate, each containing a Waterloo Emitter^TM. The oxygen is expected to stimulate indigenous aerobic microbes in the aquifer to mineralize the aniline and 2,4-diaminotoluene, and the results from this are expected in the next few months.
DE: 0418 Bioremediation
DE: 0471 Oxidation/reduction reactions (4851)
DE: 1831 Groundwater quality
SC: Hydrology [H]
MN: Fall Meeting 2005