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1.
Abstract

Isolates of the organic matter in the particulate, colloidal and dissolved states were obtained by tangential flow ultrafiltration through 0.40 μm polycarbonate and ~ 1 nm (1000 NMWL?) regenerated cellulose membranes and by solid-liquid reverse phase extraction techniques. the material was analyzed qualitatively by mass spectroscopy, proton nuclear magnetic resonance, Fourier transform infrared spectroscopy, high performance liquid chromatography with fluorescence detection of labelled primary amines and amino acids, and inductively coupled plasma/mass spectroscopy. All three states are characterized by similar organic chemistries. the marine colloidal state in coastal waters off the Californian coast contains primarily carbohydrates, fatty acids, minor amounts of proteinaceous compounds and electropositive elements including aluminium and iron. Aromatic molecules and olefinic functional groups are in low concentration. the colloidal state differs qualitatively from the particulate and dissolved states. Yet all three could be derived, with degradation, from algal or macroalgal surface components.  相似文献   

2.
In aquatic systems, the bioavailability of neutral organic xenobioties is goverened by sorption processes with dissolved, colloidal and particulate organic matrices, and in case of ionogenic compounds also by the degree of dissociation or protonation. The assumption of competitive thermodynamic equilibria yields a simple quantitative characterization of the relationship between the total content of a compound and its freely dissolved fraction in aqueous solution. To a first order, the latter is often assumed to be identical with the bioavailable portion of the compound. Thermodynamic considerations lead to the lipophilicity model for the bioconcentration of chemicals dissolved in water, and inclusion of the sorption to sediments as further partitioning process allows a mechanistic interpretation of the bioaccumulation in benthic organisms in terms of a bioconcentration from the interstitial water. For organic acids and bases, recent investigations indicate that the bioavailability of ionic compound portions may be substantially increased by ion pair formation with inorganic species as well as by specific interactions with endogenous macromolecules.  相似文献   

3.
The results obtained in the four seasonal cruises planned in the PRISMA II project are reported. These concern dissolved and colloidal organic carbon, free amino acids and total dissolved carbohydrates and heterotrophic activity. Main factors controlling organic matter degradation, resulting from laboratory tests not planned in the above project, are also discussed. Dissolved organic matter shows seasonal accumulation, which may be markedly different from year to year, and large contributions by colloidal and saccharide components. Heterotrophic activities play an important role in the carbon cycle, although laboratory runs highlight limitations caused by aging of organic matter and phosphorus deficiency.  相似文献   

4.
The results obtained in the four seasonal cruises planned in the PRISMA II project are reported. These concern dissolved and colloidal organic carbon, free amino acids and total dissolved carbohydrates and heterotrophic activity. Main factors controlling organic matter degradation, resulting from laboratory tests not planned in the above project, are also discussed. Dissolved organic matter shows seasonal accumulation, which may be markedly different from year to year, and large contributions by colloidal and saccharide components. Heterotrophic activities play an important role in the carbon cycle, although laboratory runs highlight limitations caused by aging of organic matter and phosphorus deficiency.  相似文献   

5.
An overview of the methods used for the isolation and characterization of organic matter in natural waters is presented. Commonly used techniques for the concentration and isolation of organic matter from water, such as preparative chromatography, ultrafiltration and reverse osmosis, and the methods used to analyze the organic matter obtained by these methods are reviewed. the development of methods to obtain organic matter that is associated with fractions of the dissolved organic carbon other than humic substances, such as organic bases, hydrophilic organic acids and colloidal organic matter are discussed. Methods specifically used to study dissolved organic nitrogen and dissolved organic phosphorous are also discussed.  相似文献   

6.
An overview of the methods used for the isolation and characterization of organic matter in natural waters is presented. Commonly used techniques for the concentration and isolation of organic matter from water, such as preparative chromatography, ultrafiltration and reverse osmosis, and the methods used to analyze the organic matter obtained by these methods are reviewed. the development of methods to obtain organic matter that is associated with fractions of the dissolved organic carbon other than humic substances, such as organic bases, hydrophilic organic acids and colloidal organic matter are discussed. Methods specifically used to study dissolved organic nitrogen and dissolved organic phosphorous are also discussed.  相似文献   

7.
The concentrations and distribution of particulate and dissolved heavy metals, viz: Cu, Zn, Pb, Cd, Fe and Mn have been determined seasonally during 2003 in water samples collected from the Suez Canal. The presented data clarifies that the metals exhibited clear differences in their distribution between particulate and dissolved forms. The concentrations of particulate metals viz: Zn, Pb, Cd, Fe and Mn were high as compared to the dissolved form. Dissolved copper showed the highest percentage of total copper rather than particulate. The particulate forms of Pb, Cd, Fe and Mn had always-higher concentrations than the dissolved forms during the course of study except at summer season. The northern part of the Suez Canal at Port Said showed mean concentrations of particulate and dissolved Cu = 1.43 and 2.10, Zn = 8.61 and 3.17, Pb = 1.72 and 1.23, Cd = 0.35 and 0.35, Fe = 23.49 and 15.83 and Mn = 2.09 and 1.82 μg/L. These high concentrations may be attributed to the high activities, particularly, loading and unloading operations at Port Said harbour, industrial effluents and domestic drainage of Port Said city. On the other hand, Sinai side could be considered as reference site, as it is almost clean without harmful outfalls, where Cu = 0.16 and 0.56, Zn = 2.14 and 0.94, Pb = 6.29 and 3.44, Cd = 0.055 and 0.088, Fe = 6.29 and 3.44 and Mn = 0.56 and 0.26 μg/L for particulate and dissolved metals respectively.  相似文献   

8.
The origin and distribution of suspended organic matter, the trophic features and the stable carbon isotopic composition of particulate organic carbon (POC) were studied monthly in a Western Mediterranean semi-enclosed basin. Sampling stations were selected as a function of wind-exposure and the degree of vegetation cover and then compared with an adjacent unvegetated site. the predominant vegetation was seagrass (Posidonia oceanica and Cymodocea nodosa) and Caulerpa prolifera. Water samples were analyzed for total suspended matter (inorganic and organic fractions), photosynthetic pigments (chlorophyll-a and phaeopigments), dissolved organic carbon, particulate organic carbon and their isotopic composition. Temperature and salinity were also measured at the same sampling sites within range of Mediterranean limits. the suspended organic matter concentration was 1.77 ± 1.55 mg l-1; the chlorophyll-a concentration was low (0.35 ± 0.24 μg l-1); the disolved organic carbon concentration was 2,140 ± 2,010 μg l-1; the particulate organic carbon concentration was 212 ± 106 μg l-1 and the isotopic composition was 18.77 ± 2.51%°. There were significant temporal differences except for phaeopigments, POC and its POC isotopic composition, and there were no spatial differences other than for δ13C. This picture highlighted a general seasonal trend and trophical features similar to adjacent sea.

Spatial differences in δ13C showed that the source of suspended organic matter was different between stations as that between sources and wind-hydrodynamic constraints. In  相似文献   

9.
The movement of organic carbon was assessed by statistical and simulation modeling analyses in two marsh types in New Jersey;each marsh contained three water-drainage systems in which three tidal cycles were sampled in May and June 1973. Hourly water samples were obtained and filtered through a gelman Type A glass filter for separation into dissolved (DOC) and particulate (POC) organic carbon components of the total organic carbon (TOC). Simulation data showed that individual creeks and marshes functioned differently on the sampled tidal cycles in regard to net movement of water and organic carbon components. Organic carbon components exhibited similar tidal variations, with significantly lower concentrations at flood slack than at ebb slack. Mid-ebb concentrations were significantly higher than mid-flood concentrations for TOC and POC. Individual marshes showed significantly different concentrations in the latter segments of the tidal cycle for TOC's and POC's. Results indicate that individual creeks, marshes and tidal cycles are not representative of the total movement of organic carbon in estuaries.Paper of the Journal Series, New Jersey Agricultural Experiment Station, Cook College, rutgers—The state University of New Jersey, New Brunswick, New Jersey 08903, USA.  相似文献   

10.
The first incident of green oysters (Crassostrea gigas) was reported in Taiwan in the Charting coastal area in January, 1986 and mortality was reported three months later. the cause of the greened oysters was identified as copper pollution. the copper content of the green oysters was extremely high - 2100 ppm, 2225 ppm, and 4400 ppm dry weight, in January, 1986, February 1987, and January 1989, respectively. in this paper we summarize the seasonal and regional distributions of copper species (complexed by inorganic and organic ligands, labile and non-labile, polar and non-polar) and forms (dissolved and particulate) and the hydrographic and biomass parameters (mainly particulate organic carbon, chloropyll -α, adenosine triphosphate and primary production) in sea water in the Erhjin Chi coastal area. in general, high concentrations of particulate material (0.24 to 724 ppb) and non-labile organic copper (0.03 to 21.5 ppb) were observed. Low values of polar organic copper (<0.02 to 16.5 ppb) indicated that non-polar organic complexes (0.3 to 20.4 ppb) from man-made organic pollutants were the major complexes in the area studied. On the basis of this data, the cause of greening and mortality in oysters is evaluated in relation to the bioavailable copper (sum of particulate and labile copper) and copper assimilative capacity (detoxicant). Finally, the correlations between the species and forms of copper, hydrographic and biomass parameters are also discussed.  相似文献   

11.
Bacterioplankton were studied in the euphotic zone of the Southern California Bight, USA, with special attention to biological factors affecting bacterial distribution and activity. Measurements were made of bacterial abundance, thymidine incorporation into acid insoluble material, primary production (particulate and dissolved), chlorophyll, phaeopigments, total microbial ATP, particulate organic carbon and nitrogen, dissolved organic carbon, dissolved primary amines, and glucose and thymidine turnover rates. The data were analyzed by pairwise rank correlations with significance tested at the P<.005 level. Bacterial abundance and thymidine incorporation both declined progressively with increasing distance from shore (to 100 km); similar trends occurred for the phytoplankton, with several stations having subsurface maxima. Bacterial abundance, thymidine incorporation, and thymidine and glucose turnover rates were all significantly correlated to each other, suggesting they are comparable as relative measures of bacterial activity. Thymidine incorporation per cell, an indicator of specific growth rate, was not correlated to bacterial abundance, suggesting density independent specific growth rates. Bacterioplankton growth rate was evidently influenced more by the standing stock of phytoplankton than by the primary production of the phytoplankton. Thus, bacterial growth may possibly be stimulated by leakage of dissolved organic matter not so much from healthy photosynthesizing cells as from phytoplankton being disrupted and incompletely digested during predation by the zooplankton and nekton.  相似文献   

12.
Reciprocal inhibition experiments concerning the simultaneous absorption of acidic, basic and neutral amino acids give evidence that Anemonia sulcata Pennant (Coelenterata: Anthozoa) possess at least three distinct uptake systems for amino acids. The absorption of amino acids belonging to the same class is mutually inhibited. Increasing inhibitor concentrations reduce the uptake of the substrate successively, indicating that the receptors are saturated only at high substrate concentrations; this is not the case under natural conditions. The uptake system for acidic amino acids is highly specific; uptake is not inhibited by either basic or neutral amino acids. The specificity for basic amino acids is lower; uptake is influenced by neutral amino acids. Neutral amino acids are absorbed either by one single system with broad specificity or by several systems with overlapping specificity. D- and L-isomers seem to be absorbed by the same system, as the uptake is reciprocally inhibited. The restricted specificity of the amino-acid uptake systems, especially those for neutral amino acids, could be explained as an adaptation to avoid accumulation of certain amino acids in a most economic way. Moreover, a broad spectrum of various dissolved organic materials can thus be utilized. The experiments also give evidence that anemones are able to supply their metabolism completely with the necessary substances by absorbing dissolved organic material. The absorbed substances may, furthermore, be vital for the metabolism, although their individual energy content may be negligible. Anemones display optimum fitness to an important environmental factor-dissolved organic material — on a macromolecular level, in addition to structural and physiological adaptations.  相似文献   

13.
D. P. Weston 《Marine Biology》1990,107(1):159-169
This study examines the role of the organic carbon content of sediment in aromatic hydrocarbon bioaccumulation and assesses the importance of two routes of hydrocarbon uptake: (1) the uptake of the particulate contaminant fraction from ingested sediment; (2) the uptake of the dissolved contaminant fraction from interstitial or overlying water. The lugwormAbarenicola pacifica was collected from San Juan Island, Washington, USA, in January 1989, and exposed to three sediments contaminated with [3H]benzo (a) pyrene (BaP). By manipulating the organic content of these sediments, it was possible to establish three treatments with similar BaP concentrations in the interstitial water, but differing in the amount of BaP in the bulk sediment. BaP bioaccumulation over the first few days of exposure was correlated with feeding rate, suggesting that ingested sediments were a source of BaP. The greatest body burden, however, was attained in those individuals held in sediments with the lowest organic carbon content and the lowest BaP concentration. Body burden at steady state was not correlated with either BaP concentrations in bulk sediment (dry weight or organic carbon-normalized bases) or the interstitial water. Increased organic matter decreased BaP bioavailability in a non-linear fashion. Bioaccumulation factors relative to water and organic content were relatively constant between 1 and 2% organic carbon in the sediment, but these same accumulation factors substantially underestimated body burden if applied to sandy sediments with little (0.3%) organic carbon.  相似文献   

14.
The chemical characteristics of fine particulate matter (PM2.5) emitted from commercial cooking were explored in this study. Three typical commercial restaurants in Shanghai, i.e., a Shanghai-style one (SHS), a Sichuan-style one (SCS) and an Italian-style one (ITS), were selected to conduct PM2.5 sampling. Particulate organic matter (POM) was found to be the predominant contributor to cooking-related PM2.5 mass in all the tested restaurants, with a proportion of 69.1% to 77.1%. Specifically, 80 trace organic compounds were identified and quantified by gas chromatography/mass spectrometry (GC/MS), which accounted for 3.8%–6.5% of the total PM2.5 mass. Among the quantified organic compounds, unsaturated fatty acids had the highest concentration, followed by saturated fatty acids. Comparatively, the impacts of other kinds of organic compounds were much smaller. Oleic acid was the most abundant single species in both SCS and ITS. However, in the case of SHS, linoleic acid was the richest one. ITS produced a much larger mass fraction of most organic species in POM than the two Chinese cooking styles except for monosaccharide anhydrides and sterols. The results of this study could be utilized to explore the contribution of cooking emissions to PM2.5 pollution and to develop the emission inventory of PM2.5 from cooking, which could then help the policymakers design efficient treatment measures and control strategies on cooking emissions in the future.  相似文献   

15.
Acid hydrolysis of estuarine water samples for the determination of amino acids (AAs) was tested and found to be effective at high (250 μM) nitrate concentrations when the anti-oxidant, ascorbic acid, was added to the samples. Hydrolysable AA concentrations were then determined in surface sediments collected from low and high salinity regions of the Tamar Estuary (UK) during winter 2003 and 2004, and in overlying water when simulated resuspension of sediment particles was performed. Concentrations of AAs in sediment samples comprised <50% of particulate nitrogen, fitting the paradigm that most sedimentary nitrogen is preserved within an organic matrix. When sediment samples were resuspended in overlying water (salinity 17.5), the rapid, measured increase in dissolved AA concentrations almost equalled the reported nitrate concentration in the lower estuary, with the subsequent decrease in the total dissolved AA levels suggested that bacterial uptake was occurring. Our data concur with previous studies on nitrogen desorption from sediments and suggest that an understanding of organic nitrogen cycling will be an important aspect of future effective estuarine management.  相似文献   

16.
The major sources and sinks of suspended particulate carbon are identified for northern Chesapeake Bay, Maryland, USA. The area of the bay under consideration was divided into two sections. The northernmost section (upper bay), from the head of the bay to the vicinity of Baltimore, was characterized by a high input of particulate carbon from upland drainage. The section from Baltimore to the mouth of the Potomac River (middle bay) was dominated by an internal supply of particulate carbon from primary production. The northernmost section was characterized by major particulate carbon losses to the bottom and to benthic respiration, with slightly less than half (43%) of the particulate carbon respired in the water column or converted to dissolved organic matter. In contrast, respiration in the water column or conversion to dissolved organic matter was responsible for the loss of about 65% of the particulate carbon in the middle section of the bay, while losses to the bottom and to benthic respiration totaled only 12%. Even though the supply of particulate carbon to the upper bay was about 1.5 times the supply to the middle bay, the loss of carbon due to biological activity (biological efficiency) in each area was similar, and amounted to about 70% of the supply of particulate carbon.The research reported here was partially supported by the University of Maryland and by the U. S. Bureau of Sport Fisheries and Wildlife under Contract No. 14-16-0005-2096. Contribution No. 471 of the Natural Resources Institute, University of Maryland, USA.  相似文献   

17.

The interaction of hydrological, chemical and biological factors in a defined time may cause an excess bloom of phytoplankton in an ecosystem, which can persist over a long period or occur from time to time.

This phenomenon has been recorded from the northern Adriatic and coastal enclosed basins along the eastern Adriatic coast (Ka?tela Bay, Split) for a long time now.

During 1988 this phenomenon of increased production was recorded from almost the entire northern and middle Adriatic with some traces even in its southern part. Some preliminary results for that period point to the fact that this was caused very likely by exceptionally warm and dry weather, with no significant precipitations and wind. Such conditions affect horizontal and vertical stratification of water masses.

High photosynthetic radiation, increased quantities of alochthonous organic matter, either in the form of particulate or dissolved organic matter, either in the form of particulate or dissolved organic carbon (POC or DOC), influx of nutrients (via rivers, municipal sewage or upwelling) are the main causes of sudden bloom and rapid reproduction rate of phytoplankton species (Diatoms) to the large quantities to which the pollution of the entire coastal area is due.  相似文献   

18.
Benthic macrofaunal populations through their feeding, bioturbation, burrow construction and sediment irrigation activities have profound influences on organic matter inputs to marine sediments (biodeposition) and on the vertical distribution of deposited organic matter within the sediment. These effects in turn influence the rates and pathways of organic matter mineralisation, and element cycles. Similarly, bioturbation, burrow construction and burrow irrigation are major determinants of sediment-water column fluxes of oxygen and nutrients.

In this review, I discuss the influences of the different benthic macrofaunal feeding (functional) groups on mineralisation processes and sediment-water column fluxes of particulate and dissolved nutrients. How these effects influence diagenic processes, the balance between aerobic and anaerobic processes, and the redox status of the surficial sediments. Finally, I discuss some of the limitations of the predominantly laboratory techniques which have been used to study “macrofaunal effects” and how this hinders the inclusion of the effects in quantitative sediment biogeochemical models.  相似文献   

19.
A comparative analysis of data, obtained during four indoor-mesocosm experiments with natural spring plankton communities from the Baltic Sea, was conducted to investigate whether biogeochemical cycling is affected by an increase in water temperature of up to 6?°C above present-day conditions. In all experiments, warming stimulated in particular heterotrophic bacterial processes and had an accelerating effect on the temporal development of phytoplankton blooms. This was also mirrored in the build-up and partitioning of organic matter between particulate and dissolved phases. Thus, warming increased both the magnitude and rate of dissolved organic carbon (DOC) build-up, whereas the accumulation of particulate organic carbon (POC) and phosphorus (POP) decreased with rising temperature. In concert, the observed temperature-mediated changes in biogeochemical components suggest strong shifts in the functioning of marine pelagic food webs and the ocean’s biological carbon pump, hence providing potential feedback mechanisms to Earth’s climate system.  相似文献   

20.
M. Alber  I. Valiela 《Marine Biology》1994,121(2):259-265
Two marine mussels, Geukensia demissa (Dillwyn) and Mytilus edulis (L.) collected in 1990 in Old Silver Beach, Falmouth, Massachusetts, incorporated nitrogen when fed 15N-labelled organic aggregates produced from dissolved organic nitrogen released by the brown sea-weed Fucus vesiculosis. Uptake of 15N on the aggregate diet was linear over the course of 24 h, and unincorporated 15N was eliminated from the gut after 48 h. Both species of mussels incorporated approximately five times more N when they were fed organic aggregates than when they were fed either 15N-labelled dissolved organic material (DOM) or particulate detritus, both of which were also derived from the seaweed. Nitrogen uptake was greatest in controls fed the diatom Thalassiosira weissflogii; mussels fed phytoplankton incorporated seven times more nitrogen than those fed aggregates. However, aggregates could supply an estimated 7 to 14% of the N requirements for both mussels, whereas DOM or particulate detritus could only supply 1 to 3%. These data provide evidence that a food web pathway exists from primary producer to released dissolved organic nitrogen to microbial organic aggregate to metazoan consumer, and, further, that it can be more important in a detrital food web than either particulate detritus or DOM.  相似文献   

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