Gravity Drainage during Gas Injection

Naylor, Peter; Sargent, N. C.; Crosbie, A. J.; Tilsed, A. P.; Goodyear, S.G.

doi:10.3997/2214-4609.201406948

Cited by 19 publications

(16 citation statements)

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“…Various studies have also indicated that NP may behave as a weak environmental estrogen ( , ). Failure to observe the formation of NP is consistent with published reports that it forms under anaerobic conditions ( , ). The conditions of the die-away experiment were aerobic.…”

Section: Resultssupporting

confidence: 91%

Static Die-away of a Nonylphenol Ethoxylate Surfactant in Estuarine Water Samples

Potter

Simmons

et al. 1998

Environ. Sci. Technol.

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The static die-away of the nonylphenol ethoxylate (NPE) surfactant used to stabilize the bitumen-water emulsion in the fuel Orimulsion was studied using estuarine water samples collected at four stations in Tampa Bay, FL. Incubations were in the dark at 28 °C for 183 days. Primary degradation was complete in 4-24 days with lag periods between 0 and 12 days. The concentration of five NPE intermediate degradation products and total surfactant were monitored at 4-8-day intervals for the first 89 days and at 30-day intervals thereafter. The intermediates detected included nonylphenol diethoxylate (NP2EO) and nonylphenoxy ethoxy acetic acid (NP2EC). Much smaller amounts of nonylphenoxy acetic acid (NP1EC) and nonylphenol monoethoxylate (NP1EO) were detected. The completely deethoxylated metabolite nonylphenol (NP) was not detected. On a molar basis, NP2EC accounted for 66.0-93.3% of degradation products and for 22.7-75.6% of the starting material at the termination of the experiment. The sequence of degradation and intermediate accumulation and decay indicated the initial formation of NP2EO from higher NPE homologues followed by oxidation to NP2EC. A second phase of the experiment was initiated on day 296. The remaining water in two sample incubation containers was combined with equal volumes of freshly collected Tampa Bay water. In three of five replicates from one sample, dieaway of the residual NP2EC began at day 20 and declined to approximately 50% of the initial concentration on day 32. In other replicates of this sample and in a second sample, no change in NP2EC or NP1EC concentrations was observed. The data have confirmed relatively rapid primary degradation of the parent NPE and the formation in sequence of two degradation products, NP2EO and NP2EC. The later compound appears to be relatively resistant to further degradation However, data did indicate that microorganisms were present in the Bay that are capable of transformation and degradation of the compound.

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Section: Resultssupporting

confidence: 91%

Static Die-away of a Nonylphenol Ethoxylate Surfactant in Estuarine Water Samples

Potter

Simmons

et al. 1998

Environ. Sci. Technol.

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“…Removal rates for NP during wastewater treatment have been shown to be 95-99% (46). Concentrations of NP in municipal wastewater effluents in the United States have been previously demonstrated to range from less than detection to 4.9 µg/L (46). These concentrations are similar to the concentrations observed in our studies.…”

Section: Discussionsupporting

confidence: 89%

“…This is an indication of inefficient treatment. Removal rates for NP during wastewater treatment have been shown to be 95-99% (46). Concentrations of NP in municipal wastewater effluents in the United States have been previously demonstrated to range from less than detection to 4.9 µg/L (46).…”

Section: Discussionmentioning

confidence: 99%

Analytical Methods for Detection of Selected Estrogenic Compounds in Aqueous Mixtures

Snyder

Keith

Verbrugge

et al. 1999

Environ. Sci. Technol.

371

212

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Both natural estrogens and synthetic compounds that mimic estrogen can reach the aquatic environment through wastewater discharges. Because nonylphenol (NP), octylphenol (OP), nonylphenol polyethoxylates (NPE), 17βestradiol (E2), and ethynylestradiol (EE2) have previously been found to be estrogenic and to occur in wastewater effluents, they were the primary analytes for which the method was developed. Water samples were extracted in situ using solid-phase extraction disks. Analytes were separated by high-pressure liquid chromatography and detected by fluorescence or competitive radioimmunoassay (RIA). Method detection limits (MDLs) using HPLC with fluorescence detection were 11, 2, and 52 ng/L of water for NP, OP, and NPE, respectively. The RIA MDLs for E2 and EE2 were 107 and 53 pg/L, respectively. Samples were collected from four municipal wastewater treatment plants in south central Michigan, eight locations on the Trenton Channel of the Detroit River, MI, and five locations in Lake Mead, NV. Concentrations of NP and OP ranged from less than the MDL to 37 and 0.7 µg/L, respectively. NPE concentrations ranged from less than the MDL to 332 µg/L. Concentrations of E2 and EE2 ranged from less than the MDLs to 3.7 and 0.8 ng/L, respectively.

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“…1 In 1995, 500,000 metric tonnes of APnEOs were produced world-wide. 2 NPnEOs are synthesised by addition of ethylene oxide to 4-nonylphenol (4-NP) under alkaline conditions. 3 4-NP is the commercial description for a complex mixture of alkyl-chainsubstituted phenols with predominantly nine C-atoms in the carbon chain.…”

Section: Introductionmentioning

confidence: 99%

Occurrence and behaviour of 4-nonylphenol in river water of Germany

Fries

Püttmann

2003

J. Environ. Monit.

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An analytical method composed of solid-phase-extraction (SPE) followed by gas chromatography-mass spectrometry (GC-MS) has been developed to investigate the occurrence and the behaviour of the endocrine disruptor 4-nonylphenol (4-NP) in river water of Germany. 16 Para-isomers of the complex mixture of 4-NP isomers have been resolved in the SPE-extracts of river water samples. The mass spectra indicate the presence of four distinct groups of isomers. The different groups are characterised by different base peaks of the mass spectra dependent on the substitution of the alpha-carbon on the alkyl chain. The different isomers show (i) alpha-methyl, alpha-ethyl (base peak 149), (ii) alpha-dimethyl (base peak 135), (iii) alpha-methyl, alpha-propyl, alpha-butyl (base peak 121) and (iv) alpha-methyl, alpha-propyl, alpha-butyl (base peak 107) configuration of the alkyl chain. The recovery of the unbranched compound 4-n-NP was > or = 90%. Detection limit and determination limit of the whole analytical procedure were 6 ng L(-1) and 25 ng L(-1), respectively with a relative standard deviation of 11.7%. The concentration of the sum of the 4-NP isomers in all samples of river water ranged from 28 ng L(-1) (Elbe River) to 1220 ng L(-1)(Oder River). In a period of a higher river water level, a higher amount of 4-NP was detected in the Oder River than in a period of a lower water level. Therefore dilution was not the determinant factor of the 4-NP concentration in river water. The diurnal dynamics of the sewage treatment works (STWs) have to be considered as an influencing factor for the presence of 4-NP in river water.

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Gravity Drainage during Gas Injection

Cited by 19 publications

References 0 publications

Static Die-away of a Nonylphenol Ethoxylate Surfactant in Estuarine Water Samples

Static Die-away of a Nonylphenol Ethoxylate Surfactant in Estuarine Water Samples

Analytical Methods for Detection of Selected Estrogenic Compounds in Aqueous Mixtures

Occurrence and behaviour of 4-nonylphenol in river water of Germany

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