Biodegradation of 4-nitrophenol in standardized aquatic degradation tests

Nyholm, Niels; Lindgaard-Jørgensen, Palle; Hansen, Nis

doi:10.1016/0147-6513(84)90066-6

Cited by 50 publications

(22 citation statements)

References 14 publications

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“…It is furthermore seen that this tendency could not be revealed if only a twofold dilution was made (50 and 100 ml/L). These findings are not surprising, as similar results previously have been presented by several authors for both PNP [6,13] and other compounds [14]. At the three substrate concentrations tested, no difference in the length of lag phases and degradation rates were observed at identical bacterial concentrations.…”

Section: Resultssupporting

confidence: 92%

“…The investigations was made in simple shake flask biodegradation systems with natural bacteria from surface water [3,11] or in systems based on the International Organization for Standardization 7827 method with bacteria from wastewater treatment systems [12]. The total number of bacteria was varied either by using different concentrations of inoculum (bacteria from wastewater treatment) or by using a range of test volumes from 1.5 ml to 100 L. The study was performed with 14 C-F. Ingerslev et al (2,4-D), both well known as model compounds that sometimes fail biodegradation in standard tests [6,7]. 14 C-labeled PNP (6.6 mCi/mmol) and 2,4-D (21.8 mCi/ mmol) were obtained from Sigma-Aldrich (St. Louis, MO, USA).…”

Section: Introductionmentioning

confidence: 99%

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Importance of the test volume on the lag phase in biodegradation studies

Ingerslev

Toräng

Nyholm

2000

Enviro Toxic and Chemistry

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Abstract-Increasing the total volume of test medium resulted in decreased lag times (T L ) in biodegradability shake flask batch tests conducted with either surface water or with synthetic mineral medium inoculated with supernatant from settled activated sludge. Experiments were performed with test volumes ranging from 1.8 ml to 100 L using two 14 C-labeled model chemicals, 2,4-dichlorophenoxyacetic acid (2,4-D) and p-nitrophenol (PNP), both of which are known to be readily degradable after variable lag phases. The T L ranged from 2.1 to 30.4 d for PNP and from 16 to 37 d for 2,4-D. Decreasing the test volume tended to increase the lag time, even when a single test batch was redistributed into smaller flasks. With 5 ml supernatant added to different volumes of mineral medium, lag times for PNP were independent of the test volume in a range from 10 to 1,000 ml. At small volumes of 10 ml or less, degradation failed randomly. Our findings are partly explained by the hypotheses that a sufficient total amount as well as a sufficient concentration of specifically degrading microorganisms or consortia of bacteria must be present initially for biodegradation to get started, from which follows that with too small inoculations or with too small test volumes, biodegradation may fail randomly. A straightforward practical implication of the findings is that the test volume in biodegradability tests can significantly influence the lag time and thus sometimes be decisive for the outcome in biodegradation studies.

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Section: Resultssupporting

confidence: 92%

Section: Introductionmentioning

confidence: 99%

Importance of the test volume on the lag phase in biodegradation studies

Ingerslev

Toräng

Nyholm

2000

Enviro Toxic and Chemistry

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“…So the digester sludge bacteria required a longer time to adapt to the high stress condition. Nyholm et al (1984) mentioned that the toxic effect of substances increased the lag period of bacterial cultures. At 25 o C, at salt concentrations of 30 g/l and above, the digester sludge could not acclimate even in 50 days.…”

Section: Resultsmentioning

confidence: 99%

Specific methanogenic activity of halophilic and mixed cultures in saline wastewater

Riffat

Krongthamchat

2005

Int. J. Environ. Sci. Technol.

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ABSTRACT:Wastewater containing high concentrations of salt, are difficult to treat using biological treatment processes, especially anaerobic processes. Limited information is available on methanogenic activity in saline environments. The objective of this research was to investigate the activity of halophilic methanogens, digester sludge and a mixed culture of halophilic and methanogenic bacteria, at various levels of salinity, in terms of lag period and specific methanogenic activity (SMA) at two temperatures. For the halophilic bacteria at 35 o C, the initial SMA ranged from 0.46 to 0.90 g acetate/g VSS . d, but decreased at higher salt concentrations. The maximum SMA varied from 1.2 to 2.08 g acetate/g VSS . d. High sodium chloride concentrations had a significant adverse effect on digester sludge. At 25 o C, at salt concentrations of 30 g/l and above, the digester sludge could not acclimate even in 50 days. Little difference was observed in the maximum SMA of mixed culture and halophilic bacteria at high salt concentrations of 40 -50 g/l.

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“…Several authors have addressed problems with the protocols for ready tests [6][7][8], as these stringent tests are believed to produce false-negative results for many chemicals that are in fact rapidly degraded under environmental conditions. Falsenegative results may be due to inhibition that would not occur under natural conditions where the chemical concentrations are much lower than in the screening tests.…”

Section: Introductionmentioning

confidence: 99%

Aquatic Biodegradation Behavior of Pentachlorophenol Assessed Through a Battery of Shake Flask Die-Away Tests

Ingerslev

Baun

Nyholm

1998

Environ Toxicol Chem

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The aerobic aquatic biodegradability of pentachlorophenol (PCP) was studied in standard Organization for Economic Cooperation and Development/International Organization for Standardization shake flask screening tests for ready biodegradability and in more environmentally realistic surface water die‐away tests with low chemical concentrations. Screening tests were conducted with either activated sludge or supernatant from settled activated sludge. Concentrations of activated sludge were 30 and 0.3 mg suspended solids per liter. Sludges were either freshly collected or initially preexposed to PCP. With supernatant, only low inoculum levels were used (0.5 ml/L). Some surface water tests were carried out with sediment amendment. Added chemical concentrations ranged from 1 to 74,000 μg/L. At nontoxic concentrations, PCP was rapidly biodegradable after an adaptation period of about 10 to 20 d. At concentrations below about 10 μg/L, degradation rates decreased, and the shape of the degradation curves indicated a shift from growth‐linked degradation to non‐growth‐linked degradation. Addition of sediment to surface water reduced the acclimation periods but did not influence the subsequent degradation rate. Preexposure of activated sludge to PCP drastically eliminated the acclimation period and increased the tolerance of the sludge to PCP toxicity. With PCP used as a model compound, the results show that a battery of simple shake flask tests is suitable for provision of a detailed characterization of the biodegradability chemical compounds.

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Biodegradation of 4-nitrophenol in standardized aquatic degradation tests

Cited by 50 publications

References 14 publications

Importance of the test volume on the lag phase in biodegradation studies

Importance of the test volume on the lag phase in biodegradation studies

Specific methanogenic activity of halophilic and mixed cultures in saline wastewater

Aquatic Biodegradation Behavior of Pentachlorophenol Assessed Through a Battery of Shake Flask Die-Away Tests

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