The Structure of Hexane Soot II: Extraction Studies

Akhter, Mohammad Salim; Chughtai, A. R.; Smith, D. Moody

doi:10.1366/0003702854249204

Cited by 79 publications

(69 citation statements)

References 54 publications

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“…Lim and colleagues (2007) showed the high impact of wet deposition on the accumulation of PAHs in the SML, with an increase by a factor of up to 300 during rainfall. Because PAHs are intrinsic to the composition of BC (Akhter et al, 1984(Akhter et al, , 1985Sergides et al, 1987), the accumulation of PAHs in the SML may indicate BC enrichment.…”

Section: Introductionmentioning

confidence: 99%

Bacterial-viral interactions in the sea surface microlayer of a black carbon-dominated tropical coastal ecosystem (Halong Bay, Vietnam)

Ram

Mari

Brune

et al. 2018

Elementa: Science of the Anthropocene

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Increasing human activity has raised concerns about the impact of deposition of anthropogenic combustion aerosols (i.e., black carbon; BC) on marine processes. The sea surface microlayer (SML) is a key gate for the introduction of atmospheric BC into the ocean; however, relatively little is known of the effects of BC on bacteria-virus interactions, which can strongly influence microbially mediated processes. To study the impact of BC on bacteria-virus interactions, field investigations involving collection from the SML and underlying water were carried out in Halong Bay (Vietnam). Most inorganic nutrient concentrations, as well as dissolved organic carbon, were modestly but significantly higher (p = 0.02-0.05) in the SML than in underlying water. The concentrations of particulate organic carbon (though not chlorophyll a) and of total particulate carbon, which was composed largely of particulate BC (mean = 1.7 ± 6.4 mmol L -1 ), were highly enriched in the SML, and showed high variability among stations. On average, microbial abundances (both bacteria and viruses) and bacterial production were 2-and 5fold higher, respectively, in the SML than in underlying water. Significantly lower bacterial production (p < 0.01) was observed in the particulate fraction (>3 µm) compared to the bulk sample, but our data overall suggest that bacterial production in the SML was stimulated by particulate BC. Higher bacterial production in the SML than in underlying water supported high viral lytic infection rates (from 5.3 to 30.1%) which predominated over percent lysogeny (from undetected to 1.4%). The sorption of dissolved organic carbon by black carbon, accompanied by the high lytic infection rate in the black carbon-enriched SML, may modify microbially mediated processes and shift the net ecosystem metabolism (ratio of production and respiration) to net heterotrophy and CO 2 production in this critical layer between ocean and atmosphere.

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Section: Introductionmentioning

confidence: 99%

Bacterial-viral interactions in the sea surface microlayer of a black carbon-dominated tropical coastal ecosystem (Halong Bay, Vietnam)

Ram

Mari

Brune

et al. 2018

Elementa: Science of the Anthropocene

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“…Differences in the degree of aromaticity and polarity might be expected on the basis of the MGP process, with OG samples being more highly aromatic and CG samples having more polarity but a less aromatic nature (3,40). As discussed above, the OG samples that have high carbon contents look and feel like lampblack soot, a carbon type that has been reported to reduce PAH mobility (41).…”

Section: Mobile Concentration Comparisons the Results Inmentioning

confidence: 98%

“…The Excel "Solver" regression routine was used to fit release data to eq 1. The parameters of fit were F, k1, and k2 as previously described (5,40,41). The SFE data were analyzed using the same empirical two-site model described in the water/XAD2 extraction section, except that the units of time were minutes rather than days.…”

Section: Methodsmentioning

confidence: 99%

“…While the "stepwise" SFE approach described above imitates approaches such as the use of different organic solvents to increase extraction strength (37,39,40), other approaches to mimic the environmental release of sequestered organics are based on kinetic release curves generated with a single experimental condition. For example, desorption of organics from sediments into water is normally performed for several months, and the desorption rate curves are evaluated to determine "fast" (rapid-desorbing) and "slow" fractions for individual pollutant species (34,36).…”

Section: Single Condition Sfe Extraction Rates Vs Bioremediationmentioning

confidence: 99%

“…The need to understand the uptake and release of persistent organic pollutants has led to various laboratory approaches for determining the degree of "availability" (whether to water or to biological systems) of organics on soils and sediments. Tests include long-term (several months) water rate-of-release studies (34)(35)(36), biological availability assays such as earthworm uptake (37), to chemical assays including solid-phase extraction (37,38), organic solvent extraction with mild solvents (37,39,40), dialysis (41), and pyrolysis (42). For the purpose of assessing the risk associated with a chemical in soil or sediment, it would be useful to have a rapid laboratory test capable of predicting the fraction of chemicals that are "available" for biological uptake, treatment, and water transport.…”

Section: Introductionmentioning

confidence: 99%

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JV Task 92 - Alcoa/Retec SFE and SPME

Hawthorne¹

2009

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This report summarizes the work performed by the Energy & Environmental Research Center (EERC) under the U.S. Department of Energy Jointly Sponsored Research Program JV Task 92, which is a continuation of JV9. Successful studies performed in 1999 through the end of 2008 demonstrated the potential for using selective supercritical fluid extraction (SFE) and a solid-phase microextraction (SPME) method for measuring sediment pore water polycyclic aromatic hydrocarbons (PAHs) to mimic the bioavailability of PAHs from manufactured gas plant and aluminum smelter soils and sediments both in freshwater and saltwater locations. The studies that the EERC has performed with the commercial partners have continued to generate increased interest in both the regulatory communities and in the industries that have historically produced or utilized coal tar products. Both ASTM International and the U.S. Environmental Protection Agency (EPA) have accepted the pore water method developed at the EERC as standard methods. The studies have demonstrated the effectiveness of our techniques in predicting bioavailability of PAHs from ca. 250 impacted and background field sediments and soils. The field demonstrations from the final years of the project continued to build the foundation data for acceptance of our methods by the regulatory communities. The JV92 studies provide the single largest database in the world that includes measures of PAH bioavailability along with biological end points. These studies clearly demonstrated that present regulatory paradigms based on equilibrium partitioning greatly overpredict bioavailability. These investigations also laid the foundation for present (non-JV) studies being applied to PAHs and polychlorinated biphenyls (PCBs) at EPA Superfund sites, investigations into PAH and PCB bioavailability at U.S Department of Defense sites, and the application of the techniques to investigating the bioavailability of chlorinated dioxins and furans from impacted sediments.

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Interactions of Anthropogenic Organic Chemicals with Natural Organic Matter and Black Carbon in Environmental Particles

Pignatello

2011

Biophysico‐Chemical Processes of Anthropogenic Organic Compounds in Environmental Systems

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The Structure of Hexane Soot II: Extraction Studies

Cited by 79 publications

References 54 publications

Bacterial-viral interactions in the sea surface microlayer of a black carbon-dominated tropical coastal ecosystem (Halong Bay, Vietnam)

Bacterial-viral interactions in the sea surface microlayer of a black carbon-dominated tropical coastal ecosystem (Halong Bay, Vietnam)

JV Task 92 - Alcoa/Retec SFE and SPME

Interactions of Anthropogenic Organic Chemicals with Natural Organic Matter and Black Carbon in Environmental Particles

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