Effects of Lugworms and Seagrass on Kepone® (Chlordecone) Distribution in Sediment/Water Laboratory Systems

O'Neill, Ellen J.; Monti, Carol A.; Pritchard, P. H.; Bourquin, A. W.; Ahearn, Donald G.

doi:10.1897/1552-8618(1985)4[453:eolaso]2.0.co;2

Cited by 4 publications

(7 citation statements)

References 7 publications

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“…The resulting turbulence apparently increased mixing of the pore water [21,23] and enhanced the diffusion of Kepone. This is the same type of mixing (but not the same magnitude) that occurs in sediments in estuaries and salt marshes as a result of current, tidal, wave and wind actions [20] and bioturbation [ 16,21,24]. Because little modeling of these mixing processes in shallow water systems (both laboratory and field) has been done, most investigators treat the processes stochastically in terms of an increased "diffusion" rate rather than an increase in an advective flow [20,22,24].…”

Section: Discussionmentioning

confidence: 96%

“…Continuous-flow experimental systems (Fig. 1 [16]. They consisted of four 3-liter reaction kettles (Pyrex Glass Co., Corning, NY), 25 cm deep and 13 cm in diameter, each containing a sediment bed (8 cm deep) covered with 1,500 ml of seawater.…”

Section: Experimental Methodsmentioning

confidence: 99%

“…The sediment was fractionated and analyzed [16] to determine the distribution of Kepone in sediment after 100, 300, 600 and 1,200 h. The thickness of each of the top two layers was less than 1.0 cm, while the bottom four layers ranged in thickness from 1.0 to 3.0 cm. The volume of interstitial water associated with the sediment was measured and the radioactivity in a 3-ml sample was determined.…”

Section: Experimental Methodsmentioning

confidence: 99%

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Movement of Kepone® (Chlordecone) Across an Undisturbed Sediment-Water Interface in Laboratory Systems

Pritchard¹,

Monti²,

O'Neill³

et al. 1986

Environ Toxicol Chem

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The distribution of KeponeO (chlordecone) in a sediment bed after various periods of continuous toxicant input to the overlying water column was determined in a laboratory system. Most of the Kepone was found to accumulate in the top 0.6 to 1.5 cm of sediment. A mathematical model was developed to predict Kepone concentrations with depth over time in the sediment. An equilibrium partition coefficient was determined from batch sorption tests and a molecular diffusion coefficient for Kepone was estimated from an empirical relationship between diffusivity and molecular weight. A computed Kepone distribution based on diffusion rates that decreased with depth and with incubation time gave the best fit to the observed data. We attribute the apparently faster rates in the upper sediment to mixing between interstitial and overlying water. Our results illustrate the value of models in conjunction with laboratory studies in defining the interactions of pollutants with sediment beds.

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Section: Discussionmentioning

confidence: 96%

Section: Experimental Methodsmentioning

confidence: 99%

Section: Experimental Methodsmentioning

confidence: 99%

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Movement of Kepone® (Chlordecone) Across an Undisturbed Sediment-Water Interface in Laboratory Systems

Pritchard¹,

Monti²,

O'Neill³

et al. 1986

Environ Toxicol Chem

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“…However, because the microbial ecology of these microcosms is poorly understood, it is extremely difficult to extrapolate data on fate and/or effects of GEMs in these systems to the environment. For xenobiotic compounds, more developed models with natural sediment and water have been described [e.g., 5,19,25,26], but generally only the fate of the pollutant has been monitored and no comparison of ecological processes in the microcosm and the field has been attempted. Cragg and Fry [9], however, compared effects of herbicide treatment on bacteria and water chemistry in microcosms with published field studies.…”

Section: Introductionmentioning

confidence: 99%

Microbial trophic interactions in aquatic microcosms designed for testing genetically engineered microorganisms: A field comparison

Kroer¹,

Coffin

1992

Microb Ecol

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Microcosms may potentially be used as tools for evaluating the fate and effects of genetically engineered microorganisms released into the environment. Extrapolation of data to the field, however, requires that the correspondence between microcosm and field is known. Microbial trophic interactions within the microbial loop were compared quantitatively and qualitatively between field and microcosms containing estuarine water with and without intact sediment cores. The comparison showed that whereas proportions between trophic levels in microcosms were qualitatively similar to those in the field, rates of microbial processes were from 25 to 40% lower in microcosms. Nitrogen cycling was disrupted in microcosms incubated in the dark to eliminate primary production. Examination of the microbial parameters further suggests that sediment in microcosms may be an important factor regulating the bacterial trophic level. These results demonstrate that analysis of microbial trophic interactions is a sensitive method for the field comparison of aquatic microcosms and a potentially useful tool in the risk assessment of genetically engineered microorganisms.

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“…Site water then was added to the vessels without resuspending the sediment. In the laboratory, the vessels were incorporated into a microcosm assembly previously described by O'Neill et al (17), except that the systems operated statically (no flow-through conditions). Air was pumped into each vessel above the water, and the air outflow tubes were connected to individual CO, traps containing 15 ml of 1 N NaOH.…”

Section: Methodsmentioning

confidence: 99%

Physical and biological parameters that determine the fate of p-chlorophenol in laboratory test systems

Pritchard

O'Neill

Spain

et al. 1987

Appl Environ Microbiol

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Shake-flask and microcosm studies were conducted to determine the fate of para-chlorophenol (p-CP) in water and sediment systems and the role of sediment and nonsediment surfaces in the biodegradation process. Biodegradation of p-CP in estuarine water samples in shake flasks was slow over incubation periods of 300 h. The addition of detrital sediment resulted in immediate and rapid degradation evidenced by the production of 14Co2 from [14C]p-CP. The addition of sterile sediment, glass beads, or sand resulted in approximately four to six times more CO2 evolution than observed in the water alone. Densities of p-CP-degrading bacteria associated with the detrital sediment were 100 times greater than those enumerated in water. Bacteria in the water and associated with the sediment after preexposure of both water and sediment of p-CP demonstrated enhanced biodegradation. In some microcosms, p-CP was degraded completely in the top 1.0 cm of intact sediment beds. Sediment reworking activities by benthic invertebrates from one site were sufficient to mix p-CP deep into the sediment bed faster than biodegradation or molecular diffusion. p-CP was persistent at lower depths of the sediment, possibly a result of reduced oxygen conditions preventing aerobic biodegradation.

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Effects of Lugworms and Seagrass on Kepone® (Chlordecone) Distribution in Sediment/Water Laboratory Systems

Cited by 4 publications

References 7 publications

Movement of Kepone® (Chlordecone) Across an Undisturbed Sediment-Water Interface in Laboratory Systems

Movement of Kepone® (Chlordecone) Across an Undisturbed Sediment-Water Interface in Laboratory Systems

Microbial trophic interactions in aquatic microcosms designed for testing genetically engineered microorganisms: A field comparison

Physical and biological parameters that determine the fate of p-chlorophenol in laboratory test systems

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