Technique for rapid prediction of long-term hydrophobic...

Details Technique for rapid prediction of long-term hydrophobic... Technique for rapid prediction of long-term hydrophobic...

2001-01-08

2003-04-08

Nghiem, Michael (Department: 2863)

Data processing: measuring, calibrating, or testing

Measurement system in a specific environment

Chemical analysis

C702S022000, C702S025000, C702S130000, C405S128100, C405S128150, C210S902000

Reexamination Certificate

active

06546341

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is directed to measurement of hydrophobic organic contaminants (“HOC”) in soil. More particularly, the present invention is directed to a method of predicting long-term desorption rates through short term measurements.
2. Background Art
Desorption rates for the release of HOCs from soils and sediments into interstitial water are typically interpreted as biphasic [1-14], with an initial rapid desorption that takes a few hours or days followed by an extremely slow desorption that can take months or years to reach an endpoint [2, 3, 12, 13, 15], and thus may result in a significant fraction sequestered in soils or sediments[2, 9, 12, 13, 15-19]. Slow desorption can be rate-limiting for biodegradation, bioremediation, and subsurface transport [13, 20-31]. Thus, it is critical for remediation efforts and application of alternative endpoints to characterize and quantify slow desorption rates.
Several analytical methods have been proposed for predicting rapidly desorbing and bioavailable fractions of sorbed HOCs. Mild solvent extraction with butanol, propanol, methanol, or ethyl acetate for short time periods ranging from 5-10 seconds [29, 46, 47] to several minutes [29, 46, 58] often parallel trends in bioavailability measured by microbial degradation or earthworm uptake. However, the solvent, dilution, agitation, and duration of extraction needed for predictive purposes will vary with each pollutant, type of microorganism, and type of soil or sediment [21, 29, 46-50], generating an impractically large matrix and highly operational results with little predictive capability. Current developments of such a matrix from methods reported in the literature are summarized in Table 1, exemplifying the arbitrary nature of solvent extraction predictions. Furthermore, addition of organic solvents could potentially swell natural organic phases in the sediments or displace HOCs from binding sites, causing a different desorption rate control compared to extraction processes occurring in natural systems [44, 51]. Finally, these quick solvent extraction techniques do not help to predict long-term desorption rates of the resistant HOC fractions, which is the limiting factor in remediation efforts.
TABLE 1
Solvent extraction methods to rapidly predict bioavailability.
HOC
Sorbent
% TOC
Predictive Method
Correlates to:
Ref.
Anthracene
Lima
11.4
Ethanol extraction
Earthworm
[46]
loam
for 1-2 minutes,
uptake,
then hypochlorite
microorganism
extraction for 2-3
degradation,
minutes
and wheat plant
uptake
Fluoranthrenepyrene
Lima
11.4
Ethyl acetate, n-
Earthworm
[46]
loam
butanol, or
uptake,
propanol extraction
microorganism
for 5 seconds on a
degradation,
vortex mixer
and wheat plan
uptake
Phenanthrene
16 soils
0.7-11
71% ethanol
Microbial
[29]
extraction for 90
mineralization
minutes
Atrazine
16 soils
0.7-11
95% ethanol
Microbial
[29]
extraction for 10
mineralization
seconds
Phenanthrene
Lima
8.7
n-butanol extraction
Microbial
[49]
loam
with agitation
mineralization
Phenanthrene
Lima
8.7
n-butanol extraction
Earthworm
[49]
loam
no agitation
uptake
Atrazine
Lima
8.7
9:1 methanol water
Earthworm
[49]
loam
extraction
uptake
Atrazine
Lima
8.7
1:1 methanol water
Microbial
[49]
loam
extraction
mineralization
15 PAHs, 2-6 rings
Harbor
2.3-8.2
Desorption into
Biodegrad-
[50]
sediments
water at 20 C. for
ation by
15 days with Tenax
landforming
as infinite sink with
(poor
agitation
correlation)
Phenanthrene
Lima
7.71
75% ethanol
Earthworm
[47]
loam
extraction for 5
uptake and
seconds with
microbial
agitation
degradation
Pyrene
Lima
7.71
Butanol extraction
Earthworm
[47]
loam
for 10 seconds with
uptake and
agitation
microbial
degradation
Pheanthrene, 4-
Lima
2.3-
Butanol extraction
Microbial
[48]
nitrophenol
loam,
19.3
for 2 minutes with
degradation
muck,
agitation
aquifer
sand
Phenanthrene
Peat soil,
5.1,
Desorption into
Microbial
[21]
silty loam
43.9
water for 21 days
mineralization
with Tenax as
earthworm
infinite sink with
uptake
agitation
Supercritical CO
2
extractions have also been used to quantify the more easily desorbed HOC fractions versus ones that are more resistant to desorption [52]. This technique is attractive because the solvent density and diffusivity are easily adjusted with temperature and pressure, and the high diffusivities and low surface tensions accelerate HOC extraction. However, it has been shown that supercritical CO
2
desorption does not parallel aqueous desorption for phenanthrene, possibly due to swelling of amorphous organic matter matrices [53]. Also, enthalpies of phenanthrene sorption to soils and systems have significantly greater magnitudes in supercritical CO
2
systems than in aqueous systems, making extrapolations between the two systems inappropriate [54,55]. Furthermore, this technique does not quantitatively predict desorption rates of the more slowly desorbing, “resistant” HOC fractions.
SUMMARY OF THE INVENTION
The present invention provides a method for rapid assessment of long-term hydrophobic organic contaminant rates by measuring desorption by water at a plurality of elevated temperatures and pressures, determination of activation energies for desorption, and predicting, based on this data, long-term desorption at ordinary temperatures and pressures. The measurements are of relatively short duration as compared with the natural long-term desorption time frame.


REFERENCES:
patent: 5391300 (1995-02-01), Webb et al.
Brusseau, M.L.;Environ. Sci. Technol., 1991, vol. 25, pp. 134-142.
Carroll, K.M.; Harkness, M.R.; Bracco, A.A.; Balcarcel, R.R.;Environ. Sci. Technol., 1994, vol. 28, pp. 253-258.
Coates, J.T.; Elzerman, A.W.;J. Contam. Hydrol., 1986, vol. 1, pp. 191-210.
Cornelissen, G.; van Noort, C.M.; Govers, H.A.J.;J. Environ. Toxicol. Chem., 1997, vol. 16, pp. 1351-1357.
DiToro, D.M.; Horzempa, L.M.;Environ. Sci. Technolol., 1982, vol. 16, pp. 594-602.
Farrell, J.; Reinhard, M.;Environ. Sci. Technol., 1994, vol. 28, pp. 63-72.
Harmon, T.C.; Roberts, P.V.;Environ. Prog., 1994, vol. 13, pp. 1-8.
Karickhoff, S.W.;In Contaminants and Sediments; Baker, R.A., Ed.; Ann Arbor Science, Ann Arbor, 1980, vol. 2, pp. 193-205.
Pavlostathls, S.G.; Mathavan, G.N.;Environ. Sci. Technol., 1992, vol. 26, pp. 532-538.
Pignatello, J.J.; Frink, C.R.; Marin, P.A.; Droste, E.X.;J. Contam. Hydrol., 1990, vol. 5, pp. 195-214.
Pignatello, J.J.;Environ. Toxicol. Chem., 1990, vol. 9, pp. 1107-1115.
Scribner, S.L.; Benzing, T.R.; Sun, S.B.; Boyd, S.A.;J. Environ. Qual., 1992, vol. 21, pp. 115-120.
pg,3
Steinberg, S.M.; Pignatello, J.J.; Sawhney, B.L.;Environ. Sci. Technol., 1987, vol. 21, pp. 1201-1208.
Werth, C.J.; Reinhard, M.;Environ. Sci. Technol., 1997, vol. 31, pp. 697-703.
Pignatello, J.J.; Ferrandino, F.J.; Huang, L.Q.;Environ. Sci. Technol., 1993, vol. 27, pp. 1563-1571.
Connaughton, D.F.; Stedinger, J.R.; Lion, L.W.; Shuler, M.L.;Environ. Sci. Technol., 1993, vol. 27, pp. 2397-2403.
Cornelissen, G.; van Zuilen, H.; van Noort, P.C.M.;Chemosphere, 1999, vol. 38, pp. 2369-2380.
Ten Hulscher, T.E.M.; Vrind, B.A.; Van den Heuvel, H.; Van der Velde, L.E.; Van Noort, P.C.M.; Beurskens, J.E.M.; Govers, H.A.J.;Environ. Sci. Technol., 1999, vol. 33, pp. 126-132.
McGroddy, S.E.; Farrington, J.W.;Environ. Sci. Technol., 1995, vol. 29, pp. 1542-1550.
White, J.C.; Kelsey, J.W. ; Hatzinger, P.B.; Alexander, M.;Environ. Toxicol. Chem., 1997, vol. 16, pp. 2040-2045.
White, J.C.; Hunter, M.; Nam, K.P.; Pignatello, J.J.; Alexander, M.;Environ. Toxicol. Chem., 1999, vol. 18, pp. 1720-1727.
Tang, J.X.; Carroquino, M.J.; Robertston, B.K.; Alexander, M.;Environ. Sci. Technol., 1998, vol. 32, pp. 3586-3590.
Scow, K.M.; Hutson, J.;Soil Sci. Soc. Am. J. 1992, vol. 56, pp. 119-127.
Scow, K.M.; Hutson, J.;Soil Sci. Soc. Am. J. 1992, vol. 56, pp. 128-134.
Nam, K.; Alexander, M.Environ. Sci. Technol.

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