TY - JOUR
T1 - Bioenhancement of NAPL pool dissolution
T2 - Experimental evaluation
AU - Seagren, Eric A.
AU - Rittmann, Bruce E.
AU - Valocchi, Albert J.
N1 - Funding Information:
The research described in this article was supported by Grant DE-FG-02-89ER60773 from the Subsurface Science Program of the Office of Health and Environmental Research, US Department of Energy (DOE). This paper has not been subjected to the DOE's peer or administrative review and, therefore, does not necessarily reflect the views of the Department and no official endorsement should be inferred. Part of this paper was presented at the 67th Annual Conference and Exposition, WEFTEC '94, of the Water Environment Federation, Chicago, IL, USA, Oct. 15–19, 1994. The authors thank Cassandra Vaughn for her laboratory assistance. Appreciation is also extended to Prof. Irwin C. Gunsalus at the University of Illinois at Urbana-Champaign for providing Pseudomonas putida PpG9 (ATCC #23973).
PY - 2002
Y1 - 2002
N2 - Experiments were conducted to quantify nonaqueous phase liquid (NAPL) pool dissolution and its enhancement by in situ biodegradation. The experiments were performed using square cross-section, glass-bead packed column reactors with a small pool of a toluene-in-dodecane mixture (toluene mole fraction, Xtol≈0.02 or 0.09). Experimental quasi-steady-state toluene dissolution fluxes were determined using a 14C-carbon mass-balance approach during water flushing with and without biodegradation. The experiments demonstrated a statistically significant bioenhancement of the toluene dissolution flux of up to roughly twofold at average pore water velocities of approximately 0.1 and 1 m/day when the toluene mole fraction was low (≈0.02); however, little or no bioenhancement was observed with the higher mole fraction (≈0.09). Although it cannot be determined conclusively, the weight of evidence based on biomass measurements and model analyses suggests that the reduced bioenhancement for the high mole fraction was due to higher dissolved toluene concentrations, which may have caused toxicity effects. Importantly, even though NAPL dissolution was not bioenhanced in every case, the biodegradation reduced toluene concentrations to low levels in the reactor effluents.
AB - Experiments were conducted to quantify nonaqueous phase liquid (NAPL) pool dissolution and its enhancement by in situ biodegradation. The experiments were performed using square cross-section, glass-bead packed column reactors with a small pool of a toluene-in-dodecane mixture (toluene mole fraction, Xtol≈0.02 or 0.09). Experimental quasi-steady-state toluene dissolution fluxes were determined using a 14C-carbon mass-balance approach during water flushing with and without biodegradation. The experiments demonstrated a statistically significant bioenhancement of the toluene dissolution flux of up to roughly twofold at average pore water velocities of approximately 0.1 and 1 m/day when the toluene mole fraction was low (≈0.02); however, little or no bioenhancement was observed with the higher mole fraction (≈0.09). Although it cannot be determined conclusively, the weight of evidence based on biomass measurements and model analyses suggests that the reduced bioenhancement for the high mole fraction was due to higher dissolved toluene concentrations, which may have caused toxicity effects. Importantly, even though NAPL dissolution was not bioenhanced in every case, the biodegradation reduced toluene concentrations to low levels in the reactor effluents.
KW - Bioenhancement
KW - Dissolution
KW - Experimental studies
KW - Nonaqueous phase liquid (NAPL)
KW - Pool
KW - Toxicity
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U2 - 10.1016/S0169-7722(01)00186-3
DO - 10.1016/S0169-7722(01)00186-3
M3 - Article
C2 - 12000093
AN - SCOPUS:0036193578
SN - 0169-7722
VL - 55
SP - 57
EP - 85
JO - Journal of Contaminant Hydrology
JF - Journal of Contaminant Hydrology
IS - 1-2
ER -