scholarly journals Distribution and Bioconcentration of Polycyclic Aromatic Hydrocarbons in Surface Water and Fishes

2012 ◽  
Vol 2012 ◽  
pp. 1-14 ◽  
Author(s):  
Haiyan Li ◽  
Yong Ran
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Solid Phase ◽  
Critical Factor ◽  
Ring Compounds ◽  
Maximum Value ◽  
Fish Samples ◽  
Polycyclic Aromatic ◽  
Partitioning Coefficients

To examine spatial distribution and bioconcentration of PAHs, water and fish samples were collected from Pearl River Delta in summer and spring, respectively. Particulate organic carbon, dissolved organic carbon, biodegradable DOC (BDOC), and chlorophyll a were measured. PAHs were dominated by 2- and 3-ring compounds in the water and SPM samples. Aqueous and solid-phase PAHs, respectively, showed significant correlations with total organic matter (TOC) in SPM or dissolved organic matter (DOC) in the water. The in-situ partitioning coefficients (logKoc, mL/g) for the samples were observed to be related tologKow, implying that the hydrophobicity of PAHs is a critical factor in their distribution. It was also observed that BCF increased with the increasingKowin the viscera of tilapia (logBCF=0.507logKow−1.368,r=0.883). However, most of the observed log BCF values in other different fish tissues at first increased with the increasing of logKow, then reached a maximum value whenlogKowis between 5 and 7, and then decreased whenlogKowis higher than 7, indicating that the value of BCF may vary due to the diversity of fish species.

Microbial-accessibility-dependent electron shuttling of in situ solid-phase organic matter in soils

Geoderma ◽  
2019 ◽  
Vol 338 ◽  
pp. 1-4 ◽  
Author(s):  
Wenbing Tan ◽  
Beidou Xi ◽  
Guoan Wang ◽  
Xiaosong He ◽  
Rutai Gao ◽  
...  
Keyword(s):  
Organic Matter ◽  
Solid Phase ◽  
Electron Shuttling

scholarly journals In Situ Miniaturised Solid Phase Extraction (m-SPE) for Organic Pollutants in Seawater Samples

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
B. Abaroa-Pérez ◽  
G. Sánchez-Almeida ◽  
J. J. Hernández-Brito ◽  
D. Vega-Moreno
Keyword(s):  
Solid Phase Extraction ◽  
Organic Pollutants ◽  
Marine Environment ◽  
Persistent Organic Pollutants ◽  
Solid Phase ◽  
In Situ Monitoring ◽  
Phase Extraction ◽  
Polycyclic Aromatic ◽  
Seawater Samples

Solid phase extraction (SPE) is a consolidated technique for determining pollutants in seawater samples. The current tendency is to miniaturise systems that extract and determine pollutants in the environment, reducing the use of organic solvents, while maintaining the quality in the extraction and preconcentration. On the other hand, there is a need to develop new extraction systems that can be fitted to in situ continual monitoring buoys, especially for the marine environment. This work has developed a first model of a low-pressure micro-SPE (m-SPE) for persistent organic pollutants (POPs) that can be simply applied to in situ monitoring in the marine environment. This system reduces the volumes of sample and solvents required in the laboratory in comparison with conventional SPE. In the future, it could be used in automated or robotic systems in marine technologies such as marine gliders and oceanographic buoys. This system has been optimised and validated to determine polycyclic aromatic hydrocarbons (PAH) in seawater samples, but it could also be applied to other kinds of persistent organic pollutants (POPs) and emerging pollutants.

Insights into the nature of cometary organic matter from terrestrial analogues

2012 ◽  
Vol 11 (2) ◽  
pp. 83-92 ◽  
Author(s):  
Richard W. Court ◽  
Mark A. Sephton
Keyword(s):  
Organic Matter ◽  
Cometary Nucleus ◽  
Cometary Nuclei ◽  
Naturally Occurring ◽  
Polycyclic Aromatic ◽  
Radiation Induced ◽  
Remote Observation ◽  
Complex Organic ◽  
Cometary Comae

AbstractThe nature of cometary organic matter is of great interest to investigations involving the formation and distribution of organic matter relevant to the origin of life. We have used pyrolysis–Fourier transform infrared (FTIR) spectroscopy to investigate the chemical effects of the irradiation of naturally occurring bitumens, and to relate their products of pyrolysis to their parent assemblages. The information acquired has then been applied to the complex organic matter present in cometary nuclei and comae. Amalgamating the FTIR data presented here with data from published studies enables the inference of other comprehensive trends within hydrocarbon mixtures as they are progressively irradiated in a cometary environment, namely the polymerization of lower molecular weight compounds; an increased abundance of polycyclic aromatic hydrocarbon structures; enrichment in 13C; reduction in atomic H/C ratio; elevation of atomic O/C ratio and increase in the temperature required for thermal degradation. The dark carbonaceous surface of a cometary nucleus will display extreme levels of these features, relative to the nucleus interior, while material in the coma will reflect the degree of irradiation experienced by its source location in the nucleus. Cometary comae with high methane/water ratios indicate a nucleus enriched in methane, favouring the formation of complex organic matter via radiation-induced polymerization of simple precursors. In contrast, production of complex organic matter is hindered in a nucleus possessing a low methane/water ration, with the complex organic matter that does form possessing more oxygen-containing species, such as alcohol, carbonyl and carboxylic acid functional groups, resulting from reactions with hydroxyl radicals formed by the radiolysis of the more abundant water. These insights into the properties of complex cometary organic matter should be of particular interest to both remote observation and space missions involving in situ analyses and sample return of cometary materials.

scholarly journals In-Situ Assessment of PAHs in Contaminated Sea Sediments

2016 ◽  
Author(s):  
Emanuela Frapiccini ◽  
Evgeniya Prokofyeva ◽  
Antonina Bondarenko ◽  
Maria Letizia Ruello ◽  
Mauro Marini
Keyword(s):  
Risk Assessment ◽  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Solid Phase ◽  
Saturated Soils ◽  
New Materials ◽  
Pollution Risk ◽  
Polycyclic Aromatic ◽  
Water Saturated

The present study describes the activities performed to test a new method for measuring the mobility of polycyclic aromatic hydrocarbons (PAHs) in the solid phase of sediments within the context of environmental pollution risk assessment. The method is based on the design of a new configuration (new materials) of the commercial passive sampler Chemcatcher as probe for predicting the bioavailability of persistent organic pollutants in marine sediments (or in water saturated soils).

scholarly journals Evidence for the priming effect in a planktonic estuarine microbial community

2015 ◽  
Author(s):  
Andrew Decker Steen ◽  
Lauren N. M. Quigley ◽  
Alison Buchan
Keyword(s):  
Alkaline Phosphatase ◽  
Organic Matter ◽  
Organic Carbon ◽  
Priming Effect ◽  
Coastal Ocean ◽  
Aquatic Systems ◽  
Residence Times ◽  
Labile Organic Carbon ◽  
Recalcitrant Organic Matter

The "priming effect", in which addition of labile substances changes the remineralization rate of recalcitrant organic matter, has been intensively studied in soils, but is less well-documented in aquatic systems. We investigated the extent to which additions of nutrients or labile organic carbon could influence remineralization rates of 14C-labeled, microbially-degraded, phytoplankton-derived organic matter (OM) in microcosms inoculated with microbial communities drawn from Groves Creek Estuary in coastal Georgia, USA. We found that amendment with labile protein plus phosphorus increased remineralization rates of degraded, phytoplankton-derived OM by up to 100%, whereas acetate slightly decreased remineralization rates relative to an unamended control. Addition of ammonium and phosphate induced a smaller effect, whereas addition of ammonium alone had no effect. Counterintuitively, alkaline phosphatase activities increased in response to the addition of protein under P-replete conditions, indicating that production of enzymes unrelated to the labile priming compound may be a mechanism for the priming effect. The observed priming effect was transient: after 36 days of incubation roughly the same quantity of organic carbon had been mineralized in all treatments including no-addition controls. This timescale is on the order of the typical hydrologic residence times of well-flushed estuaries suggesting that priming in estuaries has the potential to influence whether OC is remineralized in situ or exported to the coastal ocean.

Using diffusive gradients in thin films to probe the kinetics of metal interaction with algal exudates

2011 ◽  
Vol 8 (5) ◽  
pp. 517 ◽  
Author(s):  
Jacqueline Levy ◽  
Hao Zhang ◽  
William Davison ◽  
Rene Groben
Keyword(s):  
Thin Films ◽  
Organic Matter ◽  
Organic Carbon ◽  
Dissolved Organic Matter ◽  
Chlorella Vulgaris ◽  
Metal Speciation ◽  
The Relationship ◽  
Diffusive Gradients ◽  
Kinetics Of

Environmental context Interaction of metals with dissolved organic matter is one of the key processes defining metal bioavailability in water. The technique of diffusive gradients in thin films was used to investigate the kinetics of the interaction between metals and dissolved organic matter released by algae. For most metals the rate at which they were released from the organic matter was fast, but release of iron was kinetically limited. AbstractThe interaction of metals with organic matter is one of the key processes determining metal speciation and bioavailability in water. Fulvic acid tends to dominate dissolved organic carbon (DOC) in freshwaters, but organic carbon produced in situ, e.g. exudates released by algae and bacteria, is also significant. The technique of diffusive gradients in thin films (DGT) was used to investigate the lability of metal–exudate complexes using a kinetic signature approach. Exudates were harvested from three cultured freshwater alga (Chlorella vulgaris, Cryptomonas pyrenoidifera, Anabaena flos-aquae) and the filtered media supplemented with trace metals. DGT-labile metal concentrations and kinetic signatures were determined (24-h deployment). The relationship between Fe and DOC was a defining feature of the kinetic signatures. Iron was the most kinetically limited metal followed by Al and Cu, whereas Co, Ni and Pb were effectively completely labile. Exudates from Chlorella vulgaris produced the most DOC and the most marked kinetic limitation.

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