WorldWideScience

Sample records for aquatic organic fractions

  1. Toxicity of Water Accommodated Fractions of Estonian Shale Fuel Oils to Aquatic Organisms.

    Science.gov (United States)

    Blinova, Irina; Kanarbik, Liina; Sihtmäe, Mariliis; Kahru, Anne

    2016-02-01

    Estonia is the worldwide leading producer of the fuel oils from the oil shale. We evaluated the ecotoxicity of water accommodated fraction (WAF) of two Estonian shale fuel oils ("VKG D" and "VKG sweet") to aquatic species belonging to different trophic levels (marine bacteria, freshwater crustaceans and aquatic plants). Artificial fresh water and natural lake water were used to prepare WAFs. "VKG sweet" (lower density) proved more toxic to aquatic species than "VKG D" (higher density). Our data indicate that though shale oils were very toxic to crustaceans, the short-term exposure of Daphnia magna to sub-lethal concentrations of shale fuel oils WAFs may increase the reproductive potential of survived organisms. The weak correlation between measured chemical parameters (C10-C40 hydrocarbons and sum of 16 PAHs) and WAF's toxicity to studied species indicates that such integrated chemical parameters are not very informative for prediction of shale fuel oils ecotoxicity.

  2. Tracking transformation processes of organic micropollutants in aquatic environments using multi-element isotope fractionation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Hofstetter, Thomas B., E-mail: thomas.hofstetter@eawag.ch [Eawag, Swiss Federal Institute of Aquatic Science and Technology, CH-8600 Duebendorf (Switzerland)] [Institute of Biogeochemistry and Pollutant Dynamics (IBP), ETH Zurich, CH-8092 Zurich (Switzerland); Bolotin, Jakov [Eawag, Swiss Federal Institute of Aquatic Science and Technology, CH-8600 Duebendorf (Switzerland); Skarpeli-Liati, Marita; Wijker, Reto [Eawag, Swiss Federal Institute of Aquatic Science and Technology, CH-8600 Duebendorf (Switzerland)] [Institute of Biogeochemistry and Pollutant Dynamics (IBP), ETH Zurich, CH-8092 Zurich (Switzerland); Kurt, Zohre; Nishino, Shirley F.; Spain, Jim C. [School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA 30332 (United States)

    2011-06-15

    The quantitative description of enzymatic or abiotic transformations of man-made organic micropollutants in rivers, lakes, and groundwaters is one of the major challenges associated with the risk assessment of water resource contamination. Compound-specific isotope analysis enables one to identify (bio)degradation pathways based on changes in the contaminants' stable isotope ratios even if multiple reactive and non-reactive processes cause concentrations to decrease. Here, we investigated how the magnitude and variability of isotope fractionation in some priority pollutants is determined by the kinetics and mechanisms of important enzymatic and abiotic redox reactions. For nitroaromatic compounds and substituted anilines, we illustrate that competing transformation pathways can be assessed via trends of N and C isotope signatures.

  3. Pb-binding to various dissolved organic matter in urban aquatic systems: Key role of the most hydrophilic fraction

    Science.gov (United States)

    Pernet-Coudrier, Benoît; Companys, Encarnació; Galceran, Josep; Morey, Margalida; Mouchel, Jean-Marie; Puy, Jaume; Ruiz, Núria; Varrault, Gilles

    2011-07-01

    Dissolved organic matter (DOM) from the treated effluent of a wastewater treatment plant and from the river Seine under high human pressure has been separated into three fractions: hydrophobic (containing humic and fulvic substances), transphilic and hydrophilic using a two column array of XAD-8 and XAD-4 resins. The acid base properties and the binding characteristics with respect to Pb ions (using the new electroanalytical technique AGNES, Absence of Gradients and Nernstian Equilibrium Stripping) have been studied and fitted to NICA (Non-Ideal Competitive Isotherm). We evaluated the binding potential of each DOM fraction in order to better predict the speciation of Pb and, later, its bioavailability in the river. The total binding capacity of the different fractions to Pb, as well as the total titratable charge, reaches its maximum value at the most hydrophilic fraction from the treated effluent. Specific properties of the distribution of the complexing sites within each DOM fraction have been exposed by plotting the conditional affinity spectrum (CAS). The addition of these distributions, weighted according to the respective abundance of each organic fraction, allows for a full description of the Pb binding properties of the whole DOM of a sampling site. Despite its weak aromaticity, the hydrophilic fraction from the wastewater treatment plant effluent exhibits a high lead binding affinity, so that at typical environmental pH and free Pb levels (0.1 μg L -1), Pb is mainly bound to the most hydrophilic fraction of the treated effluent (49% of bound Pb at pH 7). This feature may greatly enhance the transport of Pb and highlights that Pb speciation should also consider other fractions apart from humic and/or fulvic acids when studying surface waters under high human pressure.

  4. Impact of Organic Contamination on Some Aquatic Organisms

    OpenAIRE

    Yasser, El-Nahhal; Shawkat, El-Najjar; Samir, Afifi

    2015-01-01

    Background: Contamination of water systems with organic compounds of agricultural uses pose threats to aquatic organisms. Carbaryl, chlorpyrifos, and diuron were considered as model aquatic pollutants in this study. The main objective of this study was to characterize the toxicity of organic contamination to two different aquatic organisms. Materials and Methods: Low concentrations (0.0–60 µmol/L) of carbaryl, diuron and very low concentration (0.0–0.14 µmol/L) of chlorpyrifos and their mixtu...

  5. Hydrogen Isotope Fractionation in Aquatic Primary Producers: Implications for Food Web Studies

    Science.gov (United States)

    Hondula, K. L.; Pace, M. L.; Cole, J. J.; Batt, R. D.

    2011-12-01

    Hydrogen in the organic matter of aquatic plants has a lower relative abundance of the deuterium isotope in comparison to hydrogen in the surrounding water due to a series of fractionation processes including photosynthesis and the biosynthesis of lipids. Expected differences between the deuterium values of different types of plant tissue have been used to observe terrestrial contributions to aquatic food webs and to discriminate organic matter sources in 3-isotope studies with more precision than in 2-isotope studies, however some values used in these studies are derived from an estimated fractionation value (ɛ) between water and plant tissue. We found significant differences in fractionation values between different groups of aquatic plants sampled from three system types: lakes, river, and coastal lagoon. Fractionation values between water and plant tissue of macrophytes and marine macroalgae were more similar to those of terrestrial plants and distinctly different than those of benthic microalgae and phytoplankton. Incorporating the variability in fractionation values between plant types will improve models and experimental designs used in isotopic food web studies for aquatic systems.

  6. Radioactive contamination of aquatic media and organisms

    International Nuclear Information System (INIS)

    After a brief account of the radioactive wastes produced by peaceful or military uses of Atomic Industry, the author first describes a series of observations carried out 'in the field' on the extent of contamination in aquatic organisms with respect to that of the medium. The experimental studies are then analysed, with reference both to the radioisotope metabolism and to the factors and types of contamination of aquatic organisms by wastes from atomic industry. A precise experimental project is presented at the end of the paper, including almost 300 references. (author)

  7. Effects of radiation on aquatic organisms

    International Nuclear Information System (INIS)

    With the onset of nuclear age, nuclear fuel cycle products, nuclear medicine techniques, disposal of radio active wastes on land or in water, fall out of testing nuclear weapons has contributed large amount of radio nuclides to the water bodies. Radio nuclides can imbalance aquatic ecosystem resulting in danger to natural life. The biological effects of radiation on aquatic life are mortality, pathophysiological, reproductive, developmental and genetic changes. A broad review of the results obtained about the aquatic organisms related to different phyla indicates that the lower or less developed or more primitive organisms are more resistant than the higher or more advanced, developed and complex organisms to ionizing radiation. The algae, protozoa are more resistant than the insects, crustaceans, molluscs and fishes. The changes in sensitivity between different stages of development have also been noted. A review of the results of exposing salmonoid gametes, eggs, fingerlings and adults to X-rays supports the concepts that radio sensitivity decreases with age. This paper presents a selective review on effects of radiation and radio nuclides on the aquatic life. It include uses and sources of radiation, effective quantity of radiation, lethal and sub lethal effect, effects on survival, growth, reproduction, behaviour, metabolism, carcinogenicity and mutagenicity. (author)

  8. Impact of Organic Contamination on Some Aquatic Organisms

    Science.gov (United States)

    Yasser, El-Nahhal; Shawkat, El-Najjar; Samir, Afifi

    2015-01-01

    Background: Contamination of water systems with organic compounds of agricultural uses pose threats to aquatic organisms. Carbaryl, chlorpyrifos, and diuron were considered as model aquatic pollutants in this study. The main objective of this study was to characterize the toxicity of organic contamination to two different aquatic organisms. Materials and Methods: Low concentrations (0.0–60 µmol/L) of carbaryl, diuron and very low concentration (0.0–0.14 µmol/L) of chlorpyrifos and their mixtures were tested against fish and Daphnia magna. Percentage of death and immobilization were taken as indicators of toxicity. Results: Toxicity results to fish and D. magna showed that chlorpyrifos was the most toxic compound (LC50 to fish and D. magna are 0.08, and 0.001 µmol/L respectively), followed by carbaryl (LC50 to fish and D. magna are 43.19 and 0.031 µmol/L), while diuron was the least toxic one (LC50 values for fish and D. magna are 43.48 and 32.11 µmol/L respectively). Mixture toxicity (binary and tertiary mixtures) showed antagonistic effects. Statistical analysis showed a significant difference among mixture toxicities to fish and D. magma. Conclusion: Fish and D. magam were sensitive to low concentrations. These data suggest potent threats to aquatic organisms from organic contamination. PMID:26862260

  9. The multixenobiotic resistance mechanism in aquatic organisms

    Energy Technology Data Exchange (ETDEWEB)

    Kurelec, B. (Center for Marine Research Zagreb, Ruder Boskovic Institute, Croatia (Yugoslavia))

    1992-01-01

    Many aquatic organisms thrive and reproduce in polluted waters. This fact indicates that they are well equipped with a defense system(s) against several toxic xenobiotics simultaneously because water pollution is typically caused by a mixture of a number of pollutants. We have found that the biochemical mechanism underlying such multixenobiotic' resistance in freshwater and marine mussel, in several marine sponges, and in freshwater fish is similar to the mechanism of multidrug resistance (MDR) found in tumor cells that became refractory to treatment with a variety of chemotherapeutic agents. All these organisms possess a verapamil-sensitive potential to bind 2-acetylaminofluorene and vincristine onto membrane vesicles. They all express mRNA for mdr1 gene, and mdr1 protein product, the glycoprotein P170. Finally, in in vivo experiments, the accumulation of xenobiotics is enhanced in all investigated organisms in the presence of verapamil, the inhibitor of the P170 extrusion pump. The knowledge that the presence of one xenobiotic may block the pumping out, and hence accelerating accumulation, of others, may help us to understand and interpret our present and past data on different environmental parameters obtained using indicator organisms.99 references.

  10. Toxicity of trifluoroacetate to aquatic organisms

    Energy Technology Data Exchange (ETDEWEB)

    Berends, A.G.; Rooij, C.G. de [Solvay S.A., Brussels (Belgium); Boutonnet, J.C. [Elf Atochem, Levallois-Perret (France); Thompson, R.S. [Zeneca Ltd., Devon (United Kingdom). Brixham Environmental Lab.

    1999-05-01

    As a result of the atmospheric degradation of several hydrofluorocarbons and hydrochlorofluorocarbons, trifluoroacetate (TFA) will be formed. Through precipitation, TFA will enter aquatic ecosystems. To evaluate the impact on the aquatic environment, an aquatic toxicity testing program was carried out with sodium trifluoroacetate (NaTFA). During acute toxicity tests, no effects of NaTFA on water fleas (Daphnia magna) and zebra fish (Danio retrio) were found at a concentration of 1,200 mg/L. A 7-d study with duckweed (Lemna gibba Ge) revealed a NOEC of 300 mg/L. On the basis of the results of five toxicity tests with Selenastrum capricornutum, they determined a NOEC of 0.12 mg/L. However, algal toxicity tests with NaTFA and Chlorella vulgaris, Scenedesmus subspicatus, Chlamydomonas reinhardtii, Dunaliella tertiolecta, Eugelan gracilis, Phaeodactylum tricornutum, Navicula pelliculosa, Skeletonema costatum, Anabaena flos-aquae, and Microcystis aeruginosa resulted in EC50 values that were all higher than 100 mg/L. The toxicity of TFA to S. capricornutum could be due to metabolic defluorination to monofluoroacetate (MFA), which is known to inhibit the citric acid cycle. A toxicity test with MFA and S. capricornutum revealed it to be about three orders of magnitude more toxic than TFA. However, a bioactivation study revealed that defluorination of TFA was less than 4%. On the other hand, S. capricornutum exposed to a toxic concentration of NaTFA showed a recovery of growth when citric acid was added, suggesting that TFA (or a metabolite of TFA) interferes with the citric acid cycle. A recovery of the growth of S. capricornutum was also found when TFA was removed from the test solutions. Therefore, TFA should be considered algistatic and not algicidic for S. capricornutum. On the basis of the combined results of the laboratory tests and a previously reported semi-field study, they can consider a TFA concentration of 0.10 mg/L as safe for the aquatic ecosystem.

  11. Modeling the role of microplastics in Bioaccumulation of organic chemicals to marine aquatic organisms. Critical Review

    NARCIS (Netherlands)

    Koelmans, A.A.

    2015-01-01

    It has been shown that ingestion of microplastics may increase bioaccumulation of organic chemicals by aquatic organisms. This paper critically reviews the literature on the effects of plastic ingestion on the bioaccumulation of organic chemicals, emphasizing quantitative approaches and mechanistic

  12. Effects of ionizing radiation on aquatic organisms and ecosystems

    International Nuclear Information System (INIS)

    A panel of experts in November 1971 specifically considered the effects of ionizing radiation on aquatic organisms and ecosystems and formulated detailed suggestions for research in the area. A further panel meeting took place in April 1974. The results of the work are presented in this report which is divided into 3 chapters in the first chapter the concentrations of natural and artificial radionuclides in aquatic environments and the radiation dose rates received by aquatic organisms are discussed. In particular, simple dosimetry models for phytoplankton, zooplankton, mollusca, crustacea and fish are presented which permit the estimation of the dose rates from incorporated radionuclides and from radionuclides in the external environment. In the second chapter the somatic and genetic effects of ionizing radiation on aquatic organisms are reviewed. Somatic effects are discussed separately as effects due to short-term (acute) exposure to near-lethal doses of radiation. Great attention is paid to the effects due to long-term (chronic) exposure at lower doses rates. Consideration is given to behaviour, repair mechanisms and metabolic stimulation after exposure, and also the influence of environmental factors on radiation effects. In the third chapter the potential effects of low-level irradiation on aquatic populations are considered. First, the possible consequences of somatic effects on egg and larval mortality, stock-recruitment, fecundity and ecosystem stability are discussed. Subsequently, the assessment of genetic effects as they relate to population genetics and increased mutation rates are considered

  13. Analytical fractionation of aquatic humic substances and their metal species by means of multistage ultrafiltration.

    Science.gov (United States)

    Aster, B; Burba, P; Broekaert, J A

    1996-03-01

    The molecular-size fractionation of aquatic humic substances (HS) and their metal species by means of a novel sequential-stage ultrafiltration (UF) device equipped with five appropriate ultramembranes (1, 5, 10, 50 and 100 kD) is described. First of all, the concentration dynamics of macromolecules, particulary HS, during five-stage UF and its subsequent washing step has been modelled. Based on these results, the fractionation of aquatic HS (from ground and bog water) by means of multistage UF has been optimized for an analytical scale (10 ml sample, 1 mg/ml HS, 10 ml washing solution, pH 6.0). The molecular size-distribution of selected aquatic HS (BOC 1/2 from the "DFG-Versuchsfeld Bocholt", VM 5 from "Venner Moor", Germany) studied by five-stage UF exhibited strong systematic influences of the procedure used for their isolation. The molecular-size distribution of HS obtained by on-line UF and gel permeation chromatography (GPC) showed a satisfactory agreement in the range 1-50 kD. Moreover, when interrupting multistage UF for > 48 h a slow transformation in the HS samples has been found as gradually additional HS fractions of 50 kD, which seemed to be rather acid-inert. With complexation times of 10 kD) has been found.

  14. Photodegradation behaviour of estriol: An insight on natural aquatic organic matter influence.

    Science.gov (United States)

    Oliveira, Cindy; Lima, Diana L D; Silva, Carla Patrícia; Otero, Marta; Esteves, Valdemar I

    2016-09-01

    Estriol (E3) is one of the steroidal estrogens ubiquitously found in the aquatic environment, photodegradation being an important pathway for the elimination of such endocrine disrupting compounds. However, it is important to understand how environmentally important components present in aquatic matrices, such as organic matter, may affect their photodegradation. The main objective of this work was to investigate the photodegradation of E3 in water, under simulated solar radiation, as well as the effect of humic substances (HS - humic acids (HA), fulvic acids (FA) and XAD-4 fraction) in E3 photodegradation. Moreover, the photodegradation behaviour of E3 when present in different environmental aquatic matrices (fresh, estuarine and waste water samples) was also assessed. Results showed a completely different E3 degradation rate depending on the aquatic matrix. In ultrapure water the half-life obtained was about 50 h, while in presence of HS it varied between 5 and 10 h. Then, half-life times between 1.6 and 9.5 h were determined in environmental samples, in which it was observed that the matrix composition contributed up to 97% for the overall E3 photodegradation. Therefore, E3 photodegradation in the considered aquatic matrices was mostly caused by photosensitizing reactions (indirect photodegradation). PMID:27341158

  15. Effects of the antihistamine diphenhydramine on selected aquatic organisms.

    Science.gov (United States)

    Berninger, Jason P; Du, Bowen; Connors, Kristin A; Eytcheson, Stephanie A; Kolkmeier, Mark A; Prosser, Krista N; Valenti, Theodore W; Chambliss, C Kevin; Brooks, Bryan W

    2011-09-01

    In recent years pharmaceuticals have been detected in aquatic systems receiving discharges of municipal and industrial effluents. Although diphenhydramine (DPH) has been reported in water, sediment, and fish tissue, an understanding of its impacts on aquatic organisms is lacking. Diphenhydramine has multiple modes of action (MOA) targeting the histamine H1, acetylcholine (ACh), and 5-HT reuptake transporter receptors, and as such is used in hundreds of pharmaceutical formulations. The primary objective of this study was to develop a baseline aquatic toxicological understanding of DPH using standard acute and subchronic methodologies with common aquatic plant, invertebrate, and fish models. A secondary objective was to test the utility of leveraging mammalian pharmacology information to predict aquatic toxicity thresholds. The plant model, Lemna gibba, was not adversely affected at exposures as high as 10 mg/L. In the fish model, Pimephales promelas, pH affected acute toxicity thresholds and feeding behavior was more sensitive (no-observed-effect concentration = 2.8 µg/L) than standardized survival or growth endpoints. This response threshold was slightly underpredicted using a novel plasma partitioning approach and a mammalian pharmacological potency model. Interestingly, results from both acute mortality and subchronic reproduction studies indicated that the model aquatic invertebrate, Daphnia magna, was more sensitive to DPH than the fish model. These responses suggest that DPH may exert toxicity in Daphnia through ACh and histamine MOAs. The D. magna reproduction no-observed-effect concentration of 0.8 µg/L is environmentally relevant and suggests that additional studies of more potent antihistamines and antihistamine mixtures are warranted. PMID:21647947

  16. Ecological study of some parasitic helminths of aquatic organisms

    OpenAIRE

    Geets, A.; P. Van Damme; Hamerlynck, O.

    1988-01-01

    Except for Monogenea, most other helminth parasites (Digenea, Cestoda, Nematoda and Acanthocephala) of aquatic organisms have a rather complex life cycle, which includes one or more intermediate hosts. Studies have been carried out on the elucidation of helminth life cycles and on parasite-host relationships. Knowledge of the feeding behaviour of the host is a very useful starting-point for elucidation of the life cycles of its' parasites. Asymphylodora demeli, a trematode of two sympatric go...

  17. Providing Aquatic Organism Passage in Vertically Unstable Streams

    Directory of Open Access Journals (Sweden)

    JanineM Castro

    2016-04-01

    Full Text Available Aquatic organism passage barriers have been identified as one of the key impediments to recovery of salmonids and other migratory aquatic organisms in the Pacific Northwest of the United States. As such, state and federal agencies invest millions of dollars annually to address passage barriers. Because many barriers function as ad hoc grade control structures, their removal and/or replacement can unwittingly set off a cascade of effects that can negatively impact the very habitat and passage that project proponents seek to improve. The resultant vertical instability can result in a suite of effects that range from floodplain disconnection and loss of backwater and side channel habitat, to increased levels of turbidity. Risk assessment, including an evaluation of both the stage of stream evolution and a longitudinal profile analysis, provides a framework for determining if grade control is warranted, and if so, what type of structure is most geomorphically appropriate. Potential structures include placement of large wood and roughness elements, and constructed riffles, step-pools, and cascades. The use of structure types that mimic natural reach scale geomorphic analogues should result in improved aquatic organism passage, increased structural resilience, and reduced maintenance.

  18. Influence of Organic Manure on Organic Phosphorus Fraction in Soils

    Institute of Scientific and Technical Information of China (English)

    ZHANGYONG-SONG; NIWU-ZHONG; 等

    1993-01-01

    The transformation of organic P(Po) from organic manures in two types of soils (ultisol and entisol) and the influences of external addition of organic substance or inorganic P(Pi) on Po under the condition of the 60% maximum water capacity were investigated.The results obtained from Po fractionation experiments indicated that all the Po fractions except for the highly resistant Po fraction decreased during incubation.Application of pig feces and cow feces could largely increase each fraction of Po in the soils.Immediately after application of organic manure into the soils a large part of labile and moderately labile Po from organic manure was transferred into moderately resistant Po,which might be due to the fact that Ca-or Mg-inositol P was precipitated into Fe-inositol P.However,the availability of Po from organic manure in the soils would increase again after incubation because of the transformation of moderately labile and resistant Po fractions into labile Po fractions.Addition of cellulose or Pi into the soils showed a good effect on increasing all the Po fractions except for the highly resistant Po,and this effect was much more pronounced when cellulose was applied in combination with Pi.Therefore,in view of the effect of organic manure on improving P nutrition to plant,attention should be paid to both the Po and the organic substances from organic manure,It is suggested that application of Pi fertilizer combined with organic manure may be referred to as an effective means of protecting Pi from chemical fixation in soil.

  19. Removal of terrestrial dissolved organic carbon in aquatic ecosystems of a temperate river network.

    Science.gov (United States)

    Wollheim, W. M.; Stewart, R. J.; Aiken, G.; Butler, K. D.; Morse, N.; Salisbury, J.

    2015-12-01

    Surface waters play an important role in the global carbon balance. Dissolved organic carbon (DOC) fluxes are a major transfer of terrestrial carbon to river systems, and the net removal of terrestrial DOC in aquatic systems is poorly constrained. We used a combination of spatially distributed sampling of three DOC fractions, nitrate, and chloride in streams of different size throughout a river network and modeling to quantify the net removal of terrestrial DOC relative to other constituents during a summer base flow period. The approach was applied to the 400 km2 Ipswich River watershed, MA, USA. We found that aquatic reactivity of terrestrial DOC leading to net loss is low, closer to conservative chloride than to reactive nitrogen. Net removal of DOC occurred mainly from the hydrophobic organic acid fraction, while hydrophilic and transphilic acids showed no net change. Model fits were improved using the different DOC fractions than when using bulk DOC, indicating that partitioning of bulk DOC into different fractions is critical for understanding terrestrial DOC removal. These findings suggest that river systems may have only a modest ability to alter the amounts of terrestrial DOC delivered to coastal zones.

  20. Chemodestructive fractionation of soil organic matter

    Science.gov (United States)

    Popov, A. I.; Rusakov, A. V.

    2016-06-01

    The method of chemodestructive fractionation is suggested to assess the composition of soil organic matter. This method is based on determination of the resilience of soil organic matter components and/or different parts of organic compounds to the impact of oxidizing agents. For this purpose, a series of solutions with similar concentration of the oxidant (K2Cr2O7), but with linearly increasing oxidative capacity was prepared. Chemodestructive fractionation showed that the portion of easily oxidizable (labile) organic matter in humus horizons of different soil types depends on the conditions of soil formation. It was maximal in hydromorphic soils of the taiga zone and minimal in automorphic soils of the dry steppe zone. The portion of easily oxidizable organic matter in arable soils increased with an increase in the rate of organic fertilizers application. The long-lasting agricultural use of soils and burying of the humus horizons within the upper one-meter layer resulted in the decreasing content of easily oxidizable organic matter. It was found that the portion of easily oxidizable organic matter decreases by the mid-summer or fall in comparison with the spring or early summer period.

  1. Toxicity of anthelmintic drugs (fenbendazole and flubendazole) to aquatic organisms.

    Science.gov (United States)

    Wagil, Marta; Białk-Bielińska, Anna; Puckowski, Alan; Wychodnik, Katarzyna; Maszkowska, Joanna; Mulkiewicz, Ewa; Kumirska, Jolanta; Stepnowski, Piotr; Stolte, Stefan

    2015-02-01

    Flubendazole (FLU) and fenbendazole (FEN) belong to benzimidazoles-pharmaceuticals widely used in veterinary and human medicine for the treatment of intestinal parasites as well as for the treatment of systemic worm infections. In recent years, usage of these drugs increased, which resulted in a larger contamination of the environment and possible negative effects on biota. Hence, in our research, we investigated an aquatic ecotoxicity of these pharmaceuticals towards: marine bacteria (Vibrio fischeri), green algae (Scenedesmus vacuolatus), duckweed (Lemna minor) and crustacean (Daphnia magna). Ecotoxicity tests were combined with chemical analysis in order to investigate the actual exposure concentration of the compounds used in the experiment as well as to stability and adsorption studies. As a result, study evaluating sensitivity of different aquatic organisms to these compounds and new ecotoxicological data is presented. The strongest negative impact of FLU and FEN was observed to D. magna.

  2. Toxicity of anthelmintic drugs (fenbendazole and flubendazole) to aquatic organisms.

    Science.gov (United States)

    Wagil, Marta; Białk-Bielińska, Anna; Puckowski, Alan; Wychodnik, Katarzyna; Maszkowska, Joanna; Mulkiewicz, Ewa; Kumirska, Jolanta; Stepnowski, Piotr; Stolte, Stefan

    2015-02-01

    Flubendazole (FLU) and fenbendazole (FEN) belong to benzimidazoles-pharmaceuticals widely used in veterinary and human medicine for the treatment of intestinal parasites as well as for the treatment of systemic worm infections. In recent years, usage of these drugs increased, which resulted in a larger contamination of the environment and possible negative effects on biota. Hence, in our research, we investigated an aquatic ecotoxicity of these pharmaceuticals towards: marine bacteria (Vibrio fischeri), green algae (Scenedesmus vacuolatus), duckweed (Lemna minor) and crustacean (Daphnia magna). Ecotoxicity tests were combined with chemical analysis in order to investigate the actual exposure concentration of the compounds used in the experiment as well as to stability and adsorption studies. As a result, study evaluating sensitivity of different aquatic organisms to these compounds and new ecotoxicological data is presented. The strongest negative impact of FLU and FEN was observed to D. magna. PMID:25189803

  3. Aquatic Organic Matter Fluorescence - from phenomenon to application

    Science.gov (United States)

    Reynolds, Darren

    2014-05-01

    The use of fluorescence to quantify and characterise aquatic organic matter in river, ocean, ground water and drinking and waste waters has come along way since its discovery as a phenomenon in the early 20th century. For example, there are over 100 papers published each year in international peer reviewed journals, an order of magnitude increase since a decade ago (see Figure taken from ISI database from 1989 to 2007 for publications in the fields of river water and waste water). Since then it has been extensively used as a research tool since the 1990's by scientists and is currently used for a wide variety of applications within a number of sectors. Universities, organisations and companies that research into aquatic organic matter have either recently readily use appropriate fluorescence based techniques and instrumentation. In industry and government, the technology is being taken up by environmental regulators and water and wastewater companies. This keynote presentation will give an overview of aquatic organic matter fluorescence from its conception as a phenomenon through to its current use in a variety of emerging applications within the sectors concerned with understanding, managing and monitoring the aquatic environment. About the Speaker Darren Reynolds pioneered the use of fluorescence spectroscopy for the analysis of wastewaters in the 1990's. He currently leads a research group within the Centre for Research in Biosciences and sits on the Scientific Advisory Board for the Institute of Bio-Sensing Technology at the University of the West of England, Bristol. He is a multidisciplinary scientist concerned with the development of technology platforms for applications in the fields of environment/agri-food and health. His current research interests include the development of optical technologies and techniques for environmental and biological sensing and bio-prospecting applications. He is currently involved in the development and use of synthetic biology

  4. Screening of perfluorinated chemicals (PFCs) in various aquatic organisms

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez-Sanjuan, Maria; Meyer, Johan; Damasio, Joana; Faria, Melissa; Barata, Carlos; Lacorte, Silvia [IDAEA-CSIC, Department of Environmental Chemistry, Barcelona (Spain)

    2010-10-15

    The aim of this study was to evaluate the occurrence of five perfluorinated chemicals (perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorohexane sulfonic acid (PFHxS), and perfluorobutane sulfonic acid) in aquatic organisms dwelling in either freshwater or marine ecosystems. Organisms selected were insect larvae, oysters, zebra mussels, sardines, and crabs, which are widespread in the environment and may represent potential bioindicators of exposure to PFCs. The study comprises the optimization of a solid-liquid extraction method and determination by high-performance liquid chromatography coupled to tandem mass spectrometry. Using spiked zebra mussels at 10 and 100 ng/g level, the method developed provided recoveries of 96% and 122%, and 82% to 116%, respectively, and a limit of detection between 0.07 and 0.22 ng/g ww. The method was highly sensitivity and robust to determine PFC compounds in a wide array of biological matrices, and no matrix interferents nor blank contamination was observed. Among organisms studied, none of the bivalves accumulated PFCs, and contrarily, insect larvae, followed by fish and crabs contained levels ranging from 0.23 to 144 ng/g ww of PFOS, from 0.14 to 4.3 ng/g ww of PFOA, and traces of PFNA and PFHxS. Assessment of the potential use of aquatic organisms for biomonitoring studies is further discussed. (orig.)

  5. Application of the Activity Framework for Assessing Aquatic Ecotoxicology Data for Organic Chemicals.

    Science.gov (United States)

    Thomas, Paul; Dawick, James; Lampi, Mark; Lemaire, Philippe; Presow, Shaun; van Egmond, Roger; Arnot, Jon A; Mackay, Donald; Mayer, Philipp; Galay Burgos, Malyka

    2015-10-20

    Toxicological research in the 1930s gave the first indications of the link between narcotic toxicity and the chemical activity of organic chemicals. More recently, chemical activity has been proposed as a novel exposure parameter that describes the fraction of saturation and that quantifies the potential for partitioning and diffusive uptake. In the present study, more than 2000 acute and chronic algal, aquatic invertebrates and fish toxicity data, as well as water solubility and melting point values, were collected from a series of sources. The data were critically reviewed and grouped by mode of action (MoA). We considered 660 toxicity data to be of acceptable quality. The 328 data which applied to the 72 substances identified as MoA 1 were then evaluated within the activity-toxicity framework: EC50 and LC50 values for all three taxa correlated generally well with (subcooled) liquid solubilities. Acute toxicity was typically exerted within the chemical activity range of 0.01-0.1, whereas chronic toxicity was exerted in the range of 0.001-0.01. These results confirm that chemical activity has the potential to contribute to the determination, interpretation and prediction of toxicity to aquatic organisms. It also has the potential to enhance regulation of organic chemicals by linking results from laboratory tests, monitoring and modeling programs. The framework can provide an additional line of evidence for assessing aquatic toxicity, for improving the design of toxicity tests, reducing animal usage and addressing chemical mixtures.

  6. Analytical fractionation of aquatic humic substances and their metal species by means of multistage ultrafiltration

    Energy Technology Data Exchange (ETDEWEB)

    Aster, B. [Institute for Spectrochemistry and Applied Spectroscopy, Postfach 10 1352, D-44139 Dortmund (Germany); Burba, P. [Institute for Spectrochemistry and Applied Spectroscopy, Postfach 10 1352, D-44139 Dortmund (Germany); Broekaert, J.A.C. [University of Dortmund, D-44227 Dortmund (Germany)

    1996-03-01

    The molecular-size fractionation of aquatic humic substances (HS) and their metal species by means of a novel sequential-stage ultrafiltration (UF) device equipped with five appropriate ultramembranes (1, 5, 10, 50 and 100 kD) is described. First of all, the concentration dynamics of macromolecules, particulary HS, during five-stage UF and its subsequent washing step has been modelled. Based on these results, the fractionation of aquatic HS (from ground and bog water) by means of multistage UF has been optimized for an analytical scale (10 ml sample, 1 mg/ml HS, 10 ml washing solution, pH 6.0). The molecular size-distribution of selected aquatic HS (BOC 1/2 from the ``DFG-Versuchsfeld Bocholt``, VM 5 from ``Venner Moor``, Germany) studied by five-stage UF exhibited strong systematic influences of the procedure used for their isolation. The molecular-size distribution of HS obtained by on-line UF and gel permeation chromatography (GPC) showed a satisfactory agreement in the range 1-50 kD. Moreover, when interrupting multistage UF for > 48 h a slow transformation in the HS samples has been found as gradually additional HS fractions of < 1 kD have been formed. Besides unloaded HS molecules, the molecular-size distribution of freshly formed metal species of HS (1.0 mg metal/g HS of Al(III), Cd(II), Cu(II), Fe(III), Mn(II), Ni(II), Pb(II), Zn(II), each) has been characterized by multistage UF as a function of pH-value, degree of loading and complexation time. Metal determinations as carried out by flame AAS, showed that considerable metal fractions in HS especially are present in molecules > 50 kD, which seemed to be rather acid-inert. With complexation times of < 2 days a transient shift of the molecular size distribution of both HS and their metal species (e.g., Al(III), Fe(III)) to higher values (> 10 kD) has been found. (orig.). With 9 figs., 2 tabs.

  7. Controls on metal exposure to aquatic organisms in urban streams.

    Science.gov (United States)

    Turpin-Nagel, Katelyn; Vadas, Timothy M

    2016-08-10

    Streams in urban ecosystems receive metal inputs primarily from stormwater runoff and wastewater effluent. The relative contribution of these metal sources to stream impairment is difficult to discern based on simple water characteristics and biological surveys. Stream impairment in these systems is often indicated by reduced abundance and diversity of aquatic insects, which tend to be more sensitive to chronic metal exposures. Metal species and controls on metal species in both the waterborne and dietborne exposure pathways to aquatic organisms are reviewed here. In addition, ecological changes that can control dietborne species are discussed. A main focus is on how organic matter from different anthropogenic sources may control both aqueous metal speciation as well as interaction with various inorganic or microbiological surfaces in streams. Most of the reviewed research focuses on Cu, Zn or Pb as those are the primary metals of concern in developed systems and Cu and Pb have unique and strong interactions with organic matter. Recommendations for further research are described in the context of exposure species, dynamics of exposure, stoichiometry, or advanced analytical tools, and regulatory implications are discussed. PMID:27170052

  8. Life under solar UV radiation in aquatic organisms

    Science.gov (United States)

    Sinha, R. P.; Häder, D.-P.

    Aquatic photosynthetic organisms are exposed to solar ultraviolet (UV) radiation while they harvest longer wavelength radiation for energetic reasons. Solar UV-B radiation (280 - 315 nm) affects motility and orientation in motile organisms and impairs photosynthesis in cyanobacteria, phytoplankton and macroalgae as measured by monitoring oxygen production or pulse amplitude modulated fluorescence analysis. Upon moderate UV stress most organisms respond by photoinhibition which is an active downregulation of the photosynthetic electron transport in photosystem II by degradation of UV-damaged D1 protein. Photoinhibition is readily reversible during recovery in shaded conditions. Excessive UV stress causes photodamage which is not easily reversible. Another major target is the DNA where UV-B mainly induces thymine dimers. Cyanobacteria, phytoplankton and macroalgae produce scytonemin, mycosporine-like amino acids and other UV-absorbing substances to protect themselves from short wavelength solar radiation.

  9. Semipermeable membrane devices in monitoring of organic pollutants in the aquatic environment

    Energy Technology Data Exchange (ETDEWEB)

    Sabaliunas, D.

    1999-03-01

    Semipermeable membrane devices (SPMDs) are passive samplers capable of concentrating hydrophobic chemicals from water, sediments, soil and air. They consist of layflat polymeric membrane such as polyethylene containing a thin film of synthetic lipid such as triolein. The transport of hydrophobic chemicals through the membrane into the lipid is governed by the process of passive diffusion. Therefore, SPMDs sample chemicals in a way similar to organisms. This thesis deals with the application of SPMDs in the monitoring of concentrations and effects of organic pollutants in the aquatic environment. SPMDs were exposed to various pesticides (organochlorines, synthetic pyrethroids, dinitroanilines, amides) in laboratory flow-through experiments to study the uptake kinetics of organic chemicals from water. To compare the uptake of model compounds by SPMDs and aquatic organisms, the membrane samplers were exposed to chemicals side-by-side with bivalves. Mixtures of chemicals accumulated by SPMDs and mussels were tested in standard toxicity and genotoxicity assays (Microtox, Mutatox, invertebrate toxicity tests, the Ames test, sister chromatid exchange test). These studies showed that the uptake pattern of organic compounds by SPMDs and aquatic organisms was similar, and the passive samplers accumulated levels of chemicals sufficient for standard bioassays. To further validate the method, SPMDs were deployed in a number of polluted water sources in Lithuania. Bioassay-directed fractionation and chemical analytical methods were used to identify pollutants sampled (PAHs, PCBs, organochlorines) and their effects were evaluated in bioassays. SPMDs proved to be useful tools in monitoring of organic pollutants under the field conditions. Criteria for bioassays to be integrated with the SPMD technique were defined based on the results of these studies. Some important factors in the integration of SPMDs and bioassays (toxicity of SPMD-inherent oleic and sediment

  10. Biogeochemical processes governing exposure and uptake of organic pollutant compounds in aquatic organisms.

    OpenAIRE

    Farrington, J W

    1991-01-01

    This paper reviews current knowledge of biogeochemical cycles of pollutant organic chemicals in aquatic ecosystems with a focus on coastal ecosystems. There is a bias toward discussing chemical and geochemical aspects of biogeochemical cycles and an emphasis on hydrophobic organic compounds such as polynuclear aromatic hydrocarbons, polychlorinated biphenyls, and chlorinated organic compounds used as pesticides. The complexity of mixtures of pollutant organic compounds, their various modes of...

  11. Thermal effects on aquatic organisms. Annotated bibliography of the 1975 literature

    International Nuclear Information System (INIS)

    Abstracts are presented of 716 papers published during 1975 concerning thermal effects on aquatic organisms. Indexes are included for author, subject category, geographic location, toxon, title, and keywords

  12. Converging hazard assessment of gold nanoparticles to aquatic organisms.

    Science.gov (United States)

    García-Cambero, Jesús Pablo; Núñez García, Mercedes; López, Gema Díaz; Herranz, Ana López; Cuevas, Laureano; Pérez-Pastrana, Esperanza; Cuadal, Judith Sendra; Castelltort, Marc Ramis; Calvo, Argelia Castaño

    2013-10-01

    The gold nanoparticles (Au-NPs) are being increasingly used because of their huge diversity of applications, and consequently, elevated levels in the environment are expected. However, due to their physico-chemical properties and functionalization a high variety of Au-NPs can be found, and complete toxicological information for each type of Au-NPs still lacks, and even, the toxicological information for the same species is sometimes contradictory. Therefore, hazard assessment should be done case by case. Hence, the objective of this study was to obtain ecotoxicological information of the same Au-NPs in aquatic organisms and to find a rationale for Au-NPs toxicity. For such a purpose, bare and hyaluronic acid capped Au-NPs (12.5 nm) along with Au-NPs bulk material were tested on freshwater algae, Daphnia and zebrafish. Results showed that while gold nanoparticles were found to be harmless to the tested organisms, the soluble gold showed to be toxic to algae and Daphnia, with an LC50 between 1 and 2 mg L(-1). Comparing our results with those gathered in the literature, it appears that a common hazard assessment of Au-NPs on the studied organisms can be elucidated.

  13. The Global Fractionation of Persistent Organic Pollutants

    Energy Technology Data Exchange (ETDEWEB)

    Wania, F.; Mackay, D.

    1996-05-01

    As described in this report, the global distribution of persistent organic contaminants is controlled by (1) the point of discharge into the global environment, (2) the movements of atmosphere and oceans, (3) the rate of exchange processes between the atmosphere and the Earth`s surface and (4) the rate of chemical loss from various environmental phases. The strong temperature dependence of atmosphere-surface exchange favours evaporation from low and warmer latitudes and deposition in high and colder latitudes. As different chemicals have different volatilities this results in chemical fractionation along temperature, and thus latitudinal and climatic gradients. Relatively volatile chemicals with sub-cooled liquid vapour pressure P{sub L} at 25 {sup o}C from 0.01 to 1 Pa preferentially condense in polar climates, while less volatile chemicals with P{sub L} between 0.01 and 10{sup -4} Pa tend to accumulate in mid latitudes. Poleward atmospheric transport of these chemicals takes place in several steps facilitated by the seasonal fluctuation of temperature. Different chemicals will move with different meridional transport velocities depending on the capacity of the Earth`s surface to retain them. These large scale distribution processes are best understood by viewing the global environment as a complex chromatographic system. The interpretation of global distribution patterns is complicated by the large and often unknown changes in chemical emission that have occurred in time and space. 51 refs., 9 figs., 4 tabs.

  14. A method for partitioning cadmium bioaccumulated in small aquatic organisms

    Energy Technology Data Exchange (ETDEWEB)

    Siriwardena, S.N.; Rana, K.J.; Baird, D.J. [Univ. of Stirling (United Kingdom). Institute of Aquaculture

    1995-09-01

    A series of laboratory experiments was conducted to evaluate bioaccumulation and surface adsorption of aqueous cadmium (Cd) by sac-fry of the African tilapia Oreochromis niloticus. In the first experiment, the design consisted of two cadmium treatments: 15 {micro}g Cd{center_dot}L{sup {minus}1} in dilution water and a Cd-ethylenediaminetetraacetic acid (Cd-EDTA) complex at 15 {micro}m{center_dot}L{sup {minus}1}, and a water-only control. There were five replicates per treatment and 40 fish per replicate. It was found that EDTA significantly reduced the bioaccumulation of cadmium by tilapia sac-fry by 34%. Based on the results, a second experiment was conducted to evaluate four procedures: a no-rinse control; rinsing in EDTA; rinsing in distilled water; and rinsing in 5% nitric acid, for removing surface-bound Cd from exposed sac-fry. In this experiment, 30 fish in each of five replicates were exposed to 15 {micro}g Cd{center_dot}L{sup {minus}1} for 72 h, processed through the rinse procedures, and analyzed for total Cd. The EDTA rinse treatment significantly reduced (p<0.05) Cd concentrations of the exposed fish relative to those receiving no rinse. It was concluded that the EDTA rinse technique may be useful in studies evaluating the partitioning of surface-bound and accumulated cadmium in small aquatic organisms.

  15. Effects of radioactive nuclides on the reproduction of aquatic organisms

    International Nuclear Information System (INIS)

    Among various organisms in aquatic environments, fishes are more radiosensitive and critical creatures in terms of the biological effects of radionuclides on the ecosystem. The hatchability of fish eggs is not very sensitive criterion for radiation injury. The differentiation and development of the germ cells of fish embryos are inhibited by the small dose of radiation, and there is some possibility that they are more sensitive indicators of radiation effects. Chromosome aberration is used as an indicator of the effect of small dose of radiation in both cultured cells and cleaved egg cells of fishes. The late effects of radiation have been seen in fishes one or more years after the exposure to the relatively small dose of radiation. The biological materials for detecting the effect of radiation on the quantitative base in future in vitro and in vivo have been established. Current studies are directed toward finding more sensitive indicators of radiation effects, estimating more quantitatively the late effects of radiation on fishes, and analyzing the mechanism of radiation injuries. (Yamashita, S.)

  16. Insight into dissolved organic matter fractions in Lake Wivenhoe during and after a major flood.

    Science.gov (United States)

    Aryal, Rupak; Grinham, Alistair; Beecham, Simon

    2016-03-01

    Dissolved organic matter is an important component of biogeochemical processes in aquatic environments. Dissolved organic matter may consist of a myriad of different fractions and resultant processing pathways. In early January 2011, heavy rainfall occurred across South East Queensland, Australia causing significant catchment inflow into Lake Wivenhoe, which is the largest water supply reservoir for the city of Brisbane, Australia. The horizontal and vertical distributions of dissolved organic matter fractions in the lake during the flood period were investigated and then compared with stratified conditions with no catchment inflows. The results clearly demonstrate a large variation in dissolved organic matter fractions associated with inflow conditions compared with stratified conditions. During inflows, dissolved organic matter concentrations in the reservoir were fivefold lower than during stratified conditions. Within the dissolved organic matter fractions during inflow, the hydrophobic and humic acid fractions were almost half those recorded during the stratified period whilst low molecular weight neutrals were higher during the flood period compared to during the stratified period. Information on dissolved organic matter and the spatial and vertical variations in its constituents' concentrations across the lake can be very useful for catchment and lake management and for selecting appropriate water treatment processes.

  17. [Acute Toxic Effects of Bromate on Aquatic Organisms].

    Science.gov (United States)

    Wang, Zhi-wei; Liu, Dong-mei; Zhang, Wen-juan; Cui, Fu-yi

    2016-02-15

    Acute toxic effects of potassium bromate, sodium bromate and potassium bromide on luminescent bacteria, water flea, green alga and zebrafish were studied using standard toxic testing methods. The results showed that the pollutants had no effect on the luminous intensity of luminescent bacteria. The 96 h EC5. of potassium bromate on Scenedesmus obliquus was 738.18 mg x L(-1), 48 h EC50 on Daphnia magna and Moina was 154.01 mg x L(-1) was 161.80 mg x L(-1), while 48 h LC50 was 198 52 mg x L(-1), 175.68 mg x L(-1), and 96 h LC50 on zebrafish was 931.4 mg x L(-1). The 96 h EC50 of sodium bromate on Scenedesmus obliquus was 540.26 mg x L(-1), 48 h EC50 Daphnia magna and Moina was 127.90 mg x L(-1), 111.07 mg x L(-1), while 48 h LC50 was 161.80 mg x L(-1), 123.47 mg x L(-1), and 96 h LC50 on zebrafish was 1065.6 mg x L(-1). But the effects of potassium bromide on the above several kinds of aquatic organisms were far smaller than those of potassium bromate and sodium bromate. The toxic effects on test organisms were due to the impacts of bromate after the comparison of different pollutants, and the effects were more obvious with the increase of exposure time. The order of sensitivity to the toxic effects of bromate was Daphnia magna, Moina > Scenedesmus obliquus > zebrafish > Chlorella vulgaris, luminescent bacteria. PMID:27363170

  18. Copper isotope fractionation during its interaction with soil and aquatic microorganisms and metal oxy(hydr)oxides: Possible structural control

    Science.gov (United States)

    Pokrovsky, O. S.; Viers, J.; Emnova, E. E.; Kompantseva, E. I.; Freydier, R.

    2008-04-01

    This work is aimed at quantifying the main environmental factors controlling isotope fractionation of Cu during its adsorption from aqueous solutions onto common organic (bacteria, algae) and inorganic (oxy(hydr)oxide) surfaces. Adsorption of Cu on aerobic rhizospheric ( Pseudomonas aureofaciens CNMN PsB-03) and phototrophic aquatic ( Rhodobacter sp. f-7bl, Gloeocapsa sp. f-6gl) bacteria, uptake of Cu by marine ( Skeletonema costatum) and freshwater ( Navicula minima, Achnanthidium minutissimum and Melosira varians) diatoms, and Cu adsorption onto goethite (FeOOH) and gibbsite (AlOOH) were studied using a batch reaction as a function of pH, copper concentration in solution and time of exposure. Stable isotopes of copper in selected filtrates were measured using Neptune multicollector ICP-MS. Irreversible incorporation of Cu in cultured diatom cells at pH 7.5-8.0 did not produce any isotopic shift between the cell and solution (Δ 65/63Cu(solid-solution)) within ±0.2‰. Accordingly, no systematic variation was observed during Cu adsorption on anoxygenic phototrophic bacteria ( Rhodobacter sp.), cyanobacteria ( Gloeocapsa sp.) or soil aerobic exopolysaccharide (EPS)-producing bacteria ( P. aureofaciens) in circumneutral pH (4-6.5) and various exposure times (3 min to 48 h): Δ 65Cu(solid-solution) = 0.0 ± 0.4‰. In contrast, when Cu was adsorbed at pH 1.8-3.5 on the cell surface of soil the bacterium P. aureofacienshaving abundant or poor EPS depending on medium composition, yielded a significant enrichment of the cell surface in the light isotope (Δ 65Cu (solid-solution) = -1.2 ± 0.5‰). Inorganic reactions of Cu adsorption at pH 4-6 produced the opposite isotopic offset: enrichment of the oxy(hydr)oxide surface in the heavy isotope with Δ 65Cu(solid-solution) equals 1.0 ± 0.25‰ and 0.78 ± 0.2‰ for gibbsite and goethite, respectively. The last result corroborates the recent works of Mathur et al. [Mathur R., Ruiz J., Titley S., Liermann L., Buss H. and

  19. Thermal effects on aquatic organisms: annotated bibliography of the 1974 literature

    International Nuclear Information System (INIS)

    The annotated bibliography covers the 1974 literature concerning thermal effects on aquatic organisms. Emphasis is placed on the effects of the release of thermal effluents on aquatic ecosystems. Indexes are provided for: author, keywords, subject category, geographic location, taxon, and title (alphabetical listing of keyword-in-context of the nontrivial words in the title). (CH)

  20. Relationship between P and the most reactive fraction of Fe(III) oxyhydroxide in various aquatic and sedimentary environments

    Science.gov (United States)

    Anschutz, Pierre

    2014-05-01

    Phosphorus can experience a series of biogeochemical pathways. Primary P has an igneous origin and occurs mostly as apatite in bedrocks. Once P is dissolved as phosphate ion, it can incorporate organic matter or become adsorbed onto inorganic particles. The liberation of P from organic matter through bacterial respiration produces a subsequent flux back to the biota or a storage in Fe and Al oxyhydroxides, or in authigenic or biogenic phosphate minerals. The adsorption of phosphate on Fe- and Al-oxide and oxyhydroxide has been extensively studied in soil science because phosphorus is a limiting nutrient in terrestrial ecosystems, and sorptive removal of natural or fertilizer phosphorus impacts the production level of crops and forests. Fe(III) oxides/oxyhydroxides are subject to reductive dissolution, and consequently redox conditions play an important role in soil P-bioavailability. The main process of phosphorus removal from the aquatic systems is burial with sediments. Exchange between sediment and overlying water takes place through benthic biogeochemical processes, including organic-P mineralization, redox-driven Fe-P cycling, and benthic phosphorus efflux from sediments. A portion of the pore-water phosphate derived from organic matter mineralization may be adsorbed onto detrital or authigenic iron oxyhydroxides in the oxidized zone of the sediment. Once advected in the reduced zone of sediments through burial or bioturbation, the most reducible fraction of Fe(III) phase can be reduced and solubilized, leading to a release of phosphate. Eventually, P can be buried over long period as relict organic-P, P associated with refractory iron oxides, and apatite. Therefore, Fe-bound P is often the initial sink of P supplied by organic matter, but not the major final sink. Several techniques have been developed to extract P bound to Fe(III) phases. The citrate-dithionite buffered (CDB) solution is one of the most often used solution to measure Fe(III)-bound P. CDB

  1. Ecotoxicity of selected nano-materials to aquatic organisms.

    Science.gov (United States)

    Blaise, C; Gagné, F; Férard, J F; Eullaffroy, P

    2008-10-01

    Present knowledge concerning the ecotoxic effects of nano-materials is very limited and merits to be documented more fully. For this purpose, we appraised the toxicity of nine metallic nano-powders (copper zinc iron oxide, nickel zinc iron oxide, yttrium iron oxide, titanium dioxide, strontium ferrite, indium tin oxide, samarium oxide, erbium oxide, and holmium oxide) and of two organic nano- powders (fullerene-C60 and single-walled carbon nanotube or SWCNT). After a simple process where nano-powders (NPs) were prepared in aqueous solution and filtered, they were then bioassayed across several taxonomic groups including decomposers (bacteria), primary producers (micro-algae), as well as primary and secondary consumers (micro-invertebrates and fish). Toxicity data generated on the 11 NPs reflected a wide spectrum of sensitivity that was biological level-, test-, and endpoint-specific. With all acute and chronic tests confounded for these 11 NPs, toxicity responses spanned over three orders of magnitude: >463 mg/L (24 h LC50 of the invertebrate Thamnoplatyurus platyurus for fullerene-C60) / 0.3 mg/L (96 h EC50 of the invertebrate Hydra attenuata for indium tin oxide), that is a ratio of 1543. On the basis of the MARA (Microbial Array for Risk Assessment) assay toxic fingerprint concept, it is intimated that NPs may have different modes of toxic action. When mixed in a 1:1 ratio with a certified reference material (CRM) sediment, two solid phase assays and an elutriate assay, respectively, showed that five NPs (copper zinc iron oxide, samarium oxide, erbium oxide, holmium oxide, and SWCNT) were able to increase both CRM sediment toxicity and its elutriate toxicity. This initial investigation suggests that chemicals emerging from nanotechnology may pose a risk to aquatic life in water column and sediment compartments and that further studies on their adverse effects are to be encouraged.

  2. Biodegradability of dissolved organic carbon in permafrost soils and aquatic systems: a meta-analysis

    Science.gov (United States)

    Vonk, J. E.; Tank, S. E.; Mann, P. J.; Spencer, R. G. M.; Treat, C. C.; Striegl, R. G.; Abbott, B. W.; Wickland, K. P.

    2015-12-01

    As Arctic regions warm and frozen soils thaw, the large organic carbon pool stored in permafrost becomes increasingly vulnerable to decomposition or transport. The transfer of newly mobilized carbon to the atmosphere and its potential influence upon climate change will largely depend on the degradability of carbon delivered to aquatic ecosystems. Dissolved organic carbon (DOC) is a key regulator of aquatic metabolism, yet knowledge of the mechanistic controls on DOC biodegradability is currently poor due to a scarcity of long-term data sets, limited spatial coverage of available data, and methodological diversity. Here, we performed parallel biodegradable DOC (BDOC) experiments at six Arctic sites (16 experiments) using a standardized incubation protocol to examine the effect of methodological differences commonly used in the literature. We also synthesized results from 14 aquatic and soil leachate BDOC studies from across the circum-arctic permafrost region to examine pan-arctic trends in BDOC. An increasing extent of permafrost across the landscape resulted in higher DOC losses in both soil and aquatic systems. We hypothesize that the unique composition of (yedoma) permafrost-derived DOC combined with limited prior microbial processing due to low soil temperature and relatively short flow path lengths and transport times, contributed to a higher overall terrestrial and freshwater DOC loss. Additionally, we found that the fraction of BDOC decreased moving down the fluvial network in continuous permafrost regions, i.e. from streams to large rivers, suggesting that highly biodegradable DOC is lost in headwater streams. We also observed a seasonal (January-December) decrease in BDOC in large streams and rivers, but saw no apparent change in smaller streams or soil leachates. We attribute this seasonal change to a combination of factors including shifts in carbon source, changing DOC residence time related to increasing thaw-depth, increasing water temperatures later

  3. Biodegradability of dissolved organic carbon in permafrost soils and aquatic systems: a meta-analysis

    Science.gov (United States)

    Jorien E. Vonk,; Suzanne E. Tank,; Paul J. Mann,; Robert G.M. Spencer,; Claire C. Treat,; Striegl, Rob; Benjamin W. Abbott,; Wickland, Kimberly P.

    2015-01-01

    As Arctic regions warm and frozen soils thaw, the large organic carbon pool stored in permafrost becomes increasingly vulnerable to decomposition or transport. The transfer of newly mobilized carbon to the atmosphere and its potential influence upon climate change will largely depend on the degradability of carbon delivered to aquatic ecosystems. Dissolved organic carbon (DOC) is a key regulator of aquatic metabolism, yet knowledge of the mechanistic controls on DOC biodegradability is currently poor due to a scarcity of long-term data sets, limited spatial coverage of available data, and methodological diversity. Here, we performed parallel biodegradable DOC (BDOC) experiments at six Arctic sites (16 experiments) using a standardized incubation protocol to examine the effect of methodological differences commonly used in the literature. We also synthesized results from 14 aquatic and soil leachate BDOC studies from across the circum-arctic permafrost region to examine pan-arctic trends in BDOC.An increasing extent of permafrost across the landscape resulted in higher DOC losses in both soil and aquatic systems. We hypothesize that the unique composition of (yedoma) permafrost-derived DOC combined with limited prior microbial processing due to low soil temperature and relatively short flow path lengths and transport times, contributed to a higher overall terrestrial and freshwater DOC loss. Additionally, we found that the fraction of BDOC decreased moving down the fluvial network in continuous permafrost regions, i.e. from streams to large rivers, suggesting that highly biodegradable DOC is lost in headwater streams. We also observed a seasonal (January–December) decrease in BDOC in large streams and rivers, but saw no apparent change in smaller streams or soil leachates. We attribute this seasonal change to a combination of factors including shifts in carbon source, changing DOC residence time related to increasing thaw-depth, increasing water temperatures later

  4. Thermal effects on aquatic organisms. Annotated bibliography of the 1975 literature

    Energy Technology Data Exchange (ETDEWEB)

    Coutant, C.C.; Talmage, S.S.; Carrier, R.F.; Collier, B.N.; Dailey, N.S. (comps.)

    1976-10-01

    Abstracts are presented of 716 papers published during 1975 concerning thermal effects on aquatic organisms. Indexes are included for author, subject category, geographic location, toxon, title, and keywords. (CH)

  5. Linking soil organic carbon pools with measured fractions

    Science.gov (United States)

    Herbst, M.; Welp, G.; Amelung, W.; Weihermueller, L.; Vereecken, H.

    2012-04-01

    Soil organic carbon (SOC) pools play an important role for the understanding and the predictive modelling of heterotrophic respiration. One of the major issues concerning model carbon pools is their purely conceptual definition. They are just defined by a turnover rate. Despite some attempts to link the conceptual model pools to measurable SOC fractions, this challenge basically remains unsolved. In this study we introduce an empirical approach to link the model pools of RothC with measured particulate organic matter fractions and an inert carbon fraction. For 63 topsoil samples from arable fields a mid-infrared spectroscopic approach was applied to determine the carbon contents in three particle-size fractions (POM1: 2000-250 μm, POM2: 250-53 μm and POM3: 53-20 μm) and a black carbon fraction. To provide the model pools for the 63 sampling sites RothC was run into equilibrium based on site-specific soil properties and meteorological data ranging from 1961 to present. It was possible to prove a link between soil organic matter fractions and pools of RothC. The coefficient of correlation between fPOM (POM1+POM2) and the resistant plant material (RPM) pool was 0.73. However, establishing multiple linear regressions based on all measured fractions instead of using just the fraction between 2000 and 53 μm significantly improved the prediction of the RPM pool. The resultant adjusted coefficient of determination using all fractions to predict RPM was 0.94. A stepwise regression algorithm based on the Akaike information criterion retained all measured fractions in the regression, pointing to the relevance of all fractions. The same was observed when linking the humic fraction of RothC (HUM) to the measured humic fractions, which were calculated as the difference between TOC and the sum of particulate and black carbon. The adjusted R2 was 0.84. Using again all measured fractions as explanatory variables for HUM increased the R2 to 0.99. From these observations we

  6. Plastic as a Carrier of POPs to Aquatic Organisms: A Model Analysis

    NARCIS (Netherlands)

    Koelmans, A.A.; Besseling, E.; Wegner, A.; Foekema, E.M.

    2013-01-01

    It has been hypothesized that persistent organic pollutants (POPs) in microplastic may pose a risk to aquatic organisms. Here we develop and analyze a conceptual model that simulates the effects of plastic on bioaccumulation of POPs. The model accounts for dilution of exposure concentration by sorpt

  7. Joint toxicity of mixtures of groups of organic aquatic pollutants to the guppy (Poecilia reticulata)

    NARCIS (Netherlands)

    Hermens, J.L.M.; Leeuwangh, Peter; Musch, Aalt

    1985-01-01

    In this study acute lethal concentrations (LC50) to the guppy (Poecilia reticulata) were determined for mixtures of 4 groups of aquatic pollutants. The groups were composed of 11 nonreactive, nonionized organic chemicals, 11 chloroanilines, 11 chlorophenols, and 9 reactive organic halides. Earlier s

  8. Body size and dispersal mode as key traits determining metacommunity structure of aquatic organisms

    NARCIS (Netherlands)

    De Bie, T.; De Meester, L.; Brendonck, L.; Martens, K.; Goddeeris, B.; Ercken, D.; Hampel, H.; Denys, L.; Vanhecke, L.; Van der Gucht, K.; Van Wichelen, J.; Vyverman, W.; Declerck, S.A.J.

    2012-01-01

    Relationships between traits of organisms and the structure of their metacommunities have so far mainly been explored with meta-analyses. We compared metacommunities of a wide variety of aquatic organism groups (12 groups, ranging from bacteria to fish) in the same set of 99 ponds to minimise biases

  9. Size-fractionated production and bioavailability of dissolved organic matter

    DEFF Research Database (Denmark)

    Knudsen-Leerbeck, Helle; Bronk, Deborah A.; Markager, Stiig

    Production and bioavailability of dissolved organic matter was quantified on a time scale of two days from size fractions ranging from bacteria to zooplankton in the York River, Virginia. The goal was to find the main contributor to DOM. Batch incubation experiments were labeled with N15-ammonium...... mainly in the phytoplankton size fraction, which on average contributed 62 % of total particulate nitrogen and 61 % of total particulate carbon. Up to 5 ± 0.4 μmol dissolved organic nitrogen L-1 and 33 ± 6.2 μmol dissolved organic carbon L-1 was produced during the incubation. Bioavailability of...

  10. Trihalomethane formation potential of organic fractions in secondary effluent

    Institute of Scientific and Technical Information of China (English)

    XUE Shuang; ZHAO Qingliang; WEI Liangliang; JIA Ting

    2008-01-01

    Organic matter is known to be the precursor of numerous chlorination by-products. Organic matter in the secondary effluent from the Wenchang Wastewater Treatment Plant(Harbin. China)was physically separated into the following fractions: particulate organic carbon(1. 2-0. 45un), colloidal organic carbon(0. 45-0. 1um), fine colloidal organic carbon(0. 1-0. 025um), and dissolved organic carbon(DOC)(<0. 025um). Moreover, <0. 45 um fraction was chemically separated into hydrophobic acid(HPO-A), hydrophobic neutral(HPO-N), transphilic acid(TPI-A), transphilic neutral(TPI-N), and hydrophilic fraction(HPI). The chlorine reactivity of these organic fractions obtained from both size and XAD fractionations were evaluated. The structural and chemical compositions of the HPO-A. HPO-N. TPI-A. and TPI-N isolates were characterized using elemental analysis(C, H, 0, and N), Fourier trailsform infrared spectroscopy(FT-IR), and proton nuclear magnetic resonance spectroscopy(1H-NMR). Results showed that Doe was dominant in terms of total concentration and trihalomethane formation potential(THMFP). and there was no statistical difference in both specific THMFP(STHMFP)and specific ultraviolet light absorbance among the 0. 45, 0. 1, and 0. 025 um filtrates. HPO-A had the highest STHMFP compared to other chemical fractions. HPO-A, HPO-N, TPI-A, and TPI-N contained 3. 02%-3. 52%of nitrogen. The molar Ratio of H/C increased in the order of HPO. Afractions. 1H-NMR analysis of the four fractions indicated that the relative content of aromatic protons in HPO-A was significantly higher than those in the others. The ratio of aliphatic to aromatic protons increased in the order of HPO-Afractions showed that HPO-A had greater aromatic C=C content whereas HPO-N, TPI-A, and TPI-N had greater aliphatic C-H content. TPI-N contained more oxygen

  11. Atmospheric transport of persistent organic pollutants to aquatic ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Agrell, Cecilia

    1999-04-01

    The load of persistent organic pollutants (POPs) is considered high in the Baltic ecosystem. The Baltic Sea spans over 12 latitudes and the regional differences in climate affect the behavior of POPs. Therefore spatial and temporal variability of the concentrations of POPs in air and precipitation within this area has been investigated at 16 (mostly rural) stations around the Baltic Sea between 1990-1993. In addition, the deposition of gaseous and particulate associated POPs to the Baltic Sea is estimated from empirical data. This atmospheric input of POPs is compared with the input from rivers. Additionally, data from Ross Island, Antarctica and Lake Kariba, Zimbabve, Africa is presented, and all results are discussed and explained using the `global fractionation hypothesis` as a framework. In the Baltic Sea, concentration of individual POPs in air were found to be influenced by their physical-chemical properties, ambient air temperature and location. A latitudinal gradient, with higher levels in the south was found for PCBs and the gradient was more pronounced for the low volatility congeners. As a result, the high volatility congeners in air increased in relative importance with latitude. Generally, PCB concentration increased with temperature, but slopes of the partial pressure in air versus reciprocal temperature were different between congeners and between stations. In general, the low volatility congeners were more temperature dependent than the high volatility PCB congeners. Steep slopes at a sampling location indicate that the concentration in air is largely determined by diffusive exchange with soils. Lack of a temperature dependence may be due to the influence of long-range transported air masses at remote sites and due to the episodic, or random nature of PCB sources at urban sites. The concentrations of individual congeners in precipitation were found to be influenced by atmospheric concentrations of PCBs, ambient temperature, precipitation volume and

  12. Interactions of mercury with different molecular weight fractions of humic substances in aquatic systems.

    Digital Repository Service at National Institute of Oceanography (India)

    Chakraborty, P.; Yao, K.M.; Chennuri, K.; Vudamala, K.; Babu, P.V.R.

    Interactions of mercury (Hg) with different molecular weight fractions of humic substances (HS) play an important role in controlling distribution, diffusion, speciation, and bioavailability of Hg in natural systems. This study suggests that Hg...

  13. Responses of Organic Phosphorus Fractionation to Environmental Conditions and Lake Evolution.

    Science.gov (United States)

    Lü, Changwei; Wang, Bing; He, Jiang; Vogt, Rolf D; Zhou, Bin; Guan, Rui; Zuo, Le; Wang, Weiying; Xie, Zhilei; Wang, Jinghua; Yan, Daohao

    2016-05-17

    Geochemical fractionation is used to assess the significance of environmental factors on organic phosphorus (OP) pools in sediments. Labile, moderately labile, and nonlabile OP pools in the sediments from Lake Hulun, Inner Mongolia, were fractionated, and their responses to environmental conditions and lake evolution were investigated based on the spatial and vertical distribution of OP fractionations. In light of the recalcitrant characteristics of organic matter (OM) in different environmental conditions, the pH presents significant negative effects on the amount of labile OP, while water depth shows an important role in regulating the distribution between the moderately labile and nonlabile OP pools. A latitudinal zonation in the distribution of OP pools in surface sediments from different lakes was apparent with this zonation likely linked to the gradient effects of climate and anthropogenic activities on OM decomposition and thereby on the sediments capacity to hold phosphorus. These results show that OM plays a role in governing the impacts of weather and environmental factors on OP fractionation in aquatic environments. This work suggests that OP pools in the sediment core could be used as an archive for environmental conditions and lake evolution. PMID:27104794

  14. Global warming and environmental contaminants in aquatic organisms: the need of the etho-toxicology approach.

    Science.gov (United States)

    Manciocco, Arianna; Calamandrei, Gemma; Alleva, Enrico

    2014-04-01

    Environmental contaminants are associated with a wide spectrum of pathological effects. Temperature increase affects ambient distribution and toxicity of these chemicals in the water environment, representing a potentially emerging problem for aquatic species with short-, medium- and long-term repercussions on human health through the food chain. We assessed peer-reviewed literature, including primary studies, review articles and organizational reports available. We focused on studies concerning toxicity of environmental pollutants within a global warming scenario. Existing knowledge on the effects that the increase of water temperature in a contaminated situation has on physiological mechanisms of aquatic organisms is presented. Altogether we consider the potential consequences for the human beings due to fish and shellfish consumption. Finally, we propose an etho-toxicological approach to study the effects of toxicants in conditions of thermal increase, using aquatic organisms as experimental models under laboratory controlled conditions.

  15. Fuzzy model for risk assessment of persistent organic pollutants in aquatic ecosystems.

    Science.gov (United States)

    Seguí, X; Pujolasus, E; Betrò, S; Agueda, A; Casal, J; Ocampo-Duque, W; Rudolph, I; Barra, R; Páez, M; Barón, E; Eljarrat, E; Barceló, D; Darbra, R M

    2013-07-01

    We developed a model for evaluating the environmental risk of persistent organic pollutants (POPs) to aquatic organisms. The model is based on fuzzy theory and uses information provided by international experts through a questionnaire. It has been tested in two case studies for a particular type of POPs: brominated flame retardants (BFRs). The first case study is related to the EU-funded AQUATERRA project, with sampling campaigns carried out in two Ebro tributaries in Spain (the Cinca and Vero Rivers). The second one, named the BROMACUA project, assessed different aquatic ecosystems in Chile (San Vicente Bay) and Colombia (Santa Marta Marsh). In both projects, the BFRs under study were polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCD). However, the model can be extrapolated to other POPs and to different aquatic ecosystems to provide useful results for decision-makers. PMID:23524177

  16. Techniques for demonstrating radiation pathology in aquatic organisms including histology and autoradiography

    International Nuclear Information System (INIS)

    Laboratory research carried out under well-designed conditions can produce reproducible results. However, if there is any variation in the experimental conditions including physical, chemical and biological factors, it may be difficult to compare the results obtained in different laboratories. The factors affecting the manifestation of radiation pathology are specially emphasized here. Radiation effects on fish and aquatic invertebrates are also described briefly. Almost all techniques developed for radiobiological research in mammals and cultured cells can be applied to research into aquatic organisms. Histopathological examination of fish should focus on the observation of the cell-renewal systems at appropriate time intervals after irradiation. Some techniques for demonstrating radiation pathology including histology and autoradiography in aquatic organisms, especially in fish, are illustrated with examples. (author)

  17. Ecotoxicogenomic Approaches for Understanding Molecular Mechanisms of Environmental Chemical Toxicity Using Aquatic Invertebrate, Daphnia Model Organism

    Directory of Open Access Journals (Sweden)

    Hyo Jeong Kim

    2015-05-01

    Full Text Available Due to the rapid advent in genomics technologies and attention to ecological risk assessment, the term “ecotoxicogenomics” has recently emerged to describe integration of omics studies (i.e., transcriptomics, proteomics, metabolomics, and epigenomics into ecotoxicological fields. Ecotoxicogenomics is defined as study of an entire set of genes or proteins expression in ecological organisms to provide insight on environmental toxicity, offering benefit in ecological risk assessment. Indeed, Daphnia is a model species to study aquatic environmental toxicity designated in the Organization for Economic Co-operation and Development’s toxicity test guideline and to investigate expression patterns using ecotoxicology-oriented genomics tools. Our main purpose is to demonstrate the potential utility of gene expression profiling in ecotoxicology by identifying novel biomarkers and relevant modes of toxicity in Daphnia magna. These approaches enable us to address adverse phenotypic outcomes linked to particular gene function(s and mechanistic understanding of aquatic ecotoxicology as well as exploration of useful biomarkers. Furthermore, key challenges that currently face aquatic ecotoxicology (e.g., predicting toxicant responses among a broad spectrum of phytogenetic groups, predicting impact of temporal exposure on toxicant responses necessitate the parallel use of other model organisms, both aquatic and terrestrial. By investigating gene expression profiling in an environmentally important organism, this provides viable support for the utility of ecotoxicogenomics.

  18. 40 CFR 230.31 - Fish, crustaceans, mollusks, and other aquatic organisms in the food web.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Fish, crustaceans, mollusks, and other aquatic organisms in the food web. 230.31 Section 230.31 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN DUMPING SECTION 404(b)(1) GUIDELINES FOR SPECIFICATION OF DISPOSAL SITES FOR DREDGED OR FILL MATERIAL...

  19. Elemental content of aquatic organisms inhabiting a pond contaminated with coal fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Furr, A.K.

    1979-01-01

    Using neutron activation and other methods, 39 elements were determined in algae, aquatic weeds, dragon fly nymphs, newts, fish and muskrats from a pond contaminated by coal fly ash. The organisms contained several elements, including selenium, at concentrations markedly higher than those in controls.

  20. Ecotoxicological assays of Diethyltoluamide and Lemongrass Essencial Oil in irradiated and non-irradiated aquatic organisms

    International Nuclear Information System (INIS)

    Aquatic invertebrates can be potentially exposed to nonradioactive contaminants in conjunction with ionizing radiation, especially in highly industrialized areas surrounding nuclear facilities, where radionuclides can accidentally be discharged in the aquatic environment containing stable chemicals. The aquatic organisms have continually been exposed to chemical contaminants like personal care products (PCPs) which have been found in various environmental matrices and may cause adverse effects to aquatic life and human health as radioactive products. In this study was used C. silvestrii as bioindicator organism in chronic ecotoxicity assays with lemongrass essencial oil (LEO) and Diethyltoluamide (DEET), both are insect repellent. In addition to exposition of the compounds, the organisms were irradiated with gamma rays from Co-60 source. Thus, the aim of this study was to evaluate the possible synergistic effect of gamma radiation and mosquito repellent products in the reproduction of Ceriodaphnia silvestrii utilizing standardized ecotoxicological tests. The C. silvestrii inhibition concentration (IC25; 7 days) result after DEET exposition was 16.4 ± 1.4 mg L-1 and for LEO was 3.1 ± 1.4 mg L-1. In the irradiated (25 Gy) C. silvestrii exposed to DEET and LEO, the concentration that inhibited reproduction was 16.1 ± 0.9 mg L-1 and 2.4 ± 0.3 mg L-1 respectively. The results showed that the reproduction of irradiated C. silvestrii was not significantly affected when compared with non-irradiated organisms when exposed to DEET or LEO. (author)

  1. AQUATIC PHOTOLYSIS OF OXY-ORGANIC COMPOUNDS ADSORBED ON GOETHITE.

    Science.gov (United States)

    Goldberg, Marvin C.

    1985-01-01

    Organic materials that will not absorb light at wavelengths longer than 295 nanometers (the solar wavelength cutoff) may nevertheless, undergo electron transfer reactions initiated by light. These reactions occur when the organic materials are adsorbed as ligand complexes to the surface of iron oxy-hydroxide (goethite). The adsorbed materials can be either inner or outer coordination sphere complexes. Goethite was chosen as the iron oxyhydroxide surface because it has the highest thermodynamic stability of any of the oxyhydroxides in water and it can be synthesized easily, with high purity.

  2. Turnover of eroded soil organic carbon after deposition in terrestrial and aquatic environments

    DEFF Research Database (Denmark)

    Kirkels, Frédérique; Cammeraat, Erik; Kalbitz, Karsten;

    The fate of eroded soil organic carbon (SOC) after deposition is a large uncertainty in assessing the impact of soil erosion on C budgets. Globally, large amounts of SOC are transported by erosion and a substantial part is transferred into adjacent inland waters, linking terrestrial and aquatic C......, with the largest increase for aquatic conditions. Solid-state 13C NMR and FT-IR spectroscopy showed broad similarities in SOC molecular composition. Soil and SOC properties could not (yet) fully explain variation in SOC turnover between the sites. However, temporal trends in CO2 emissions clearly differed between...... to better estimates of the impact of soil erosion on C budgets and reduce uncertainties in the link between terrestrial and aquatic C cycling....

  3. Daphnia as a model organism in limnology and aquatic biology: introductory remarks

    OpenAIRE

    Petrusek, Adam; Jaromir SEDA

    2011-01-01

    Cladocerans of the genus Daphnia are keystone pelagic filter feeders in many temperate ponds and lakes. They have also become popular model organisms in various biological disciplines, from aquatic ecology to biomedical sciences. The crucial features that make these organisms excellent experimental models are their cyclical parthenogenetic life cycle together with easy culturing and handling. Thanks to these characteristics, the number of publications dealing with Daphnia is rapidly growing. ...

  4. Interactions of carbon nanotubes with aqueous/aquatic media containing organic/inorganic contaminants and selected organisms of aquatic ecosystems--A review.

    Science.gov (United States)

    Boncel, Sławomir; Kyzioł-Komosińska, Joanna; Krzyżewska, Iwona; Czupioł, Justyna

    2015-10-01

    Due to their unique molecular architecture translating into numerous every-day applications, carbon nanotubes (CNTs) will be ultimately an increasingly significant environmental contaminant. This work reviews qualitative/quantitative analyses of interactions of various types of CNTs and their chemically modified analogues with aqueous/aquatic media containing organic and inorganic contaminants and selected organisms of aquatic ecosystems. A special emphasis was placed on physicochemical interactions between CNTs as adsorbents of heavy metal cations and aromatic compounds (dyes) with its environmental consequences. The studies revealed CNTs as more powerful adsorbents of aromatic compounds (an order of magnitude higher adsorption capacity) than metal cations. Depending on the presence of natural organic matter (NOM) and/or co-contaminants, CNTs may act as Trojan horse while passing through biological membranes (in the absence of NOM coordinating metal ions). Nanotubes, depending on flow conditions and their morphology/surface chemistry, may travel with natural waters or sediment with immobilized PAHs or metals and/or increase cyto- and ecotoxicity of PAHs/metal ions by their release via competitive complexation, or cause synergic ecotoxicity while adsorbing nutrients. Additionally, toxicity of CNTs against exemplary aquatic microorganisms was reviewed. It was found for Daphnia magna that longer exposures to CNTs led to higher ecotoxicity with a prolonged CNTs excretion. SWCNTs were more toxic than MWCNTs, while hydrophilization of CNTs via oxidation or anchoring thereto polar/positively charged polymer chains enhanced stability of nanotubes dispersion in aqueous media. On the other hand, bioavailability of functionalized CNTs was improved leading to more complex both mechanisms of uptake and cytotoxic effects. PMID:26022284

  5. Study on accumulation of 137Cs in aquatic organisms

    Institute of Scientific and Technical Information of China (English)

    FengDing-Hua; CheungT

    1998-01-01

    The organisms were cultivated for 7d in well water contaminated with 137Cs,The experimental results show that the accumulation level of tissues of carassius auratus had the order of gill>viscera>epidermis(including scales)>bone(including head and tail)>flesh.The concentration capability of them had the order of shrimp>carassius auratus>ophiocephalus argus,The concentration factors(CF) of shrimp was 12.6 times of that of ophiocephalus argus.

  6. Biotic ligand modeling approach: Synthesis of the effect of major cations on the toxicity of metals to soil and aquatic organisms.

    Science.gov (United States)

    Ardestani, Masoud M; van Straalen, Nico M; van Gestel, Cornelis A M

    2015-10-01

    The biotic ligand model (BLM) approach is used to assess metal toxicity, taking into account the competition of other cations with the free metal ions for binding to the biotic ligand sites of aquatic and soil organisms. The bioavailable fraction of metals, represented by the free metal ion, is a better measure than the total concentration for assessing their potential risk to the environment. Because BLMs are relating toxicity to the fraction of biotic ligands occupied by the metal, they can be useful for investigating factors affecting metal bioaccumulation and toxicity. In the present review, the effects of major cations on the toxicity of metals to soil and aquatic organisms were comprehensively studied by performing a meta-analysis of BLM literature data. Interactions at the binding sites were shown to be species- and metal-specific. The main factors affecting the relationships between toxicity and conditional binding constants for metal binding at the biotic ligand appeared to be Ca(2+) , Mg(2+) , and protons. Other important characteristics of the exposure medium, such as levels of dissolved organic carbon and concentrations of other cations, should also be considered to obtain a proper assessment of metal toxicity to soil and aquatic organisms.

  7. Nitrogen isotopic fractionation during abiotic synthesis of organic solid particles

    CERN Document Server

    Kuga, Maïa; Marty, Bernard; Marrocchi, Yves; Bernard, Sylvain; Rigaudier, Thomas; Fleury, Benjamin; Tissandier, Laurent

    2014-01-01

    The formation of organic compounds is generally assumed to result from abiotic processes in the Solar System, with the exception of biogenic organics on Earth. Nitrogen-bearing organics are of particular interest, notably for prebiotic perspectives but also for overall comprehension of organic formation in the young solar system and in planetary atmospheres. We have investigated abiotic synthesis of organics upon plasma discharge, with special attention to N isotope fractionation. Organic aerosols were synthesized from N2-CH4 and N2-CO gaseous mixtures using low-pressure plasma discharge experiments, aimed at simulating chemistry occurring in Titan s atmosphere and in the protosolar nebula, respectively. Nitrogen is efficiently incorporated into the synthesized solids, independently of the oxidation degree, of the N2 content of the starting gas mixture, and of the nitrogen speciation in the aerosols. The aerosols are depleted in 15N by 15-25 permil relative to the initial N2 gas, whatever the experimental set...

  8. Application of liquid chromatography-tandem mass spectrometry in quantitative bioanalyses of organic molecules in aquatic environment and organisms.

    Science.gov (United States)

    Bussy, Ugo; Li, Ke; Li, Weiming

    2016-05-01

    Analytical methods using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) for the simultaneous determination of metabolites or contaminants (or both) in various tissues of aquatic organisms and in the aquatic environment have received increasing attention in the last few years. This review discusses the findings relevant to such procedures published between 2005 and 2015. The aim is to evaluate the advantages, restrictions, and performances of the procedures from sample preparation to mass spectrometry measurement. To support these discussions, a general knowledge on LC-MS/MS is also provided. PMID:26996906

  9. Sludge-grown algae for culturing aquatic organisms: Part II. Sludge-grown algae as feeds for aquatic organisms

    Science.gov (United States)

    Wong, M. H.; Hung, K. M.; Chiu, S. T.

    1996-05-01

    This project investigated the feasibility of using sewage sludge to culture microalgae ( Chlorella-HKBU) and their subsequent usage as feeds for rearing different organisms. Part II of the project evaluated the results of applying the sludge-grown algae to feed Oreochromis mossambicus (fish), Macrobrachium hainenese (shrimp), and Moina macrocopa (cladocera). In general, the yields of the cultivated organisms were unsatisfactory when they were fed the sludge-grown algae directly. The body weights of O. mossambicus and M. macrocopa dropped 21% and 37%, respectively, although there was a slight increase (4.4%) in M. hainenese. However, when feeding the algal-fed cladocerans to fish and shrimp, the body weights of the fish and shrimp were increased 7% and 11% accordingly. Protein contents of the cultivated organisms were comparable to the control diet, although they contained a rather high amount of heavy metals. When comparing absolute heavy metal contents in the cultivated organisms, the following order was observed: alga > cladocera > shrimp, fish > sludge extracts. Bioelimination of heavy metals may account for the decreasing heavy metal concentrations in higher trophic organisms.

  10. 15N isotope fractionation in an aquatic food chain: Bellamya aeruginosa (Reeve) as an algal control agent.

    Science.gov (United States)

    Han, Shiqun; Yan, Shaohua; Chen, Kaining; Zhang, Zhenhua; Zed, Rengel; Zhang, Jianqiu; Song, Wei; Liu, Haiqin

    2010-01-01

    15N isotope tracer techniques and ecological modeling were adopted to investigate the fractionation of nitrogen, its uptake and transformation in algae and snail (Bellamya aeruginosa Reeve). Different algal species were found to differ in their uptake of nitrogen isotopes. Microcystis aeruginisa Kütz. demonstrated the greatest 15N accumulation capacity, with the natural variation in isotopic ratio (delta 15N) and the isotope fractionation factor (epsilon, % per hundred) being the highest among the species investigated. The transformation and utilization of 15N by snails differed depending on the specific algae consumed (highest for Chlorella pyrenoidosa Chick., lowest for M. aeruginisa). When snails was seeded in the experimental pond, the algae population structure changed significantly, and total algal biomass as well as the concentration of all nitrogen species decreased, causing an increase in water transparency. A model, incorporating several chemical and biological parameters, was developed to predict algal biomass in an aquatic system when snails was present. The data collected during this investigation indicated that the gastropods such as snails could significantly impact biological community and water quality of small water bodies, suggesting a role for biological control of noxious algal blooms associated with eutrophication. PMID:20397413

  11. Analysis of current-use pesticides in aquatic and terrestrial organisms collected throughout California, USA

    Science.gov (United States)

    Smalling, Kelly L.; Kuivila, Kathyrn M.

    2010-01-01

    A wide variety of pesticides are applied concurrently in agricultural and urban areas and transported off site dissolved in water and bound to sediments. But the exposure of aquatic and terrestrial organisms to current-use pesticides and the resulting effects are not well understood. One approach is to directly analyze tissue concentrations of contaminants. The overall objective of this study was to develop a sensitive method to analyze current-use pesticides with a wide range of Kow's in tissue to better understand the accumulation of these contaminants in different aquatic and terrestrial organisms. This method was then used to analyze current-use pesticides in tissues from a variety of organisms from sites with different land-use practices.

  12. Aquatic and terrestrial organic matter in the diet of stream consumers: implications for mercury bioaccumulation.

    Science.gov (United States)

    Jardine, Timothy D; Kidd, Karen A; Rasmussen, Joseph B

    2012-04-01

    The relative contribution of aquatic vs. terrestrial organic matter to the diet of consumers in fluvial environments and its effects on bioaccumulation of contaminants such as mercury (Hg) remain poorly understood. We used stable isotopes of carbon and nitrogen in a gradient approach (consumer isotope ratio vs. periphyton isotope ratio) across temperate streams that range in their pH to assess consumer reliance on aquatic (periphyton) vs. terrestrial (riparian vegetation) organic matter, and whether Hg concentrations in fish and their prey were related to these energy sources. Taxa varied in their use of the two sources, with grazing mayflies (Heptageniidae), predatory stoneflies (Perlidae), one species of water strider (Metrobates hesperius), and the fish blacknose dace (Rhinichthys atratulus) showing strong connections to aquatic sources, while Aquarius remigis water striders and brook trout (Salvelinus fontinalis) showed a weak link to in-stream production. The aquatic food source for consumers, periphyton, had higher Hg concentrations in low-pH waters, and pH was a much better predictor of Hg in predatory invertebrates that relied mainly on this food source vs. those that used terrestrial C. These findings suggest that stream biota relying mainly on dietary inputs from the riparian zone will be partially insulated from the effects of water chemistry on Hg availability. This has implications for the development of a whole-system understanding of nutrient and material cycling in streams, the choice of taxa in contaminant monitoring studies, and in understanding the fate of Hg in stream food webs. PMID:22645815

  13. Aquatic indicator organisms as a tool to monitor discharges from nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Outola, Iisa; Vartti, Vesa-Pekka; Klemola, Seppo [STUK - Radiation and Nuclear Safety Authority, P.O. Box 14, 00881 Helsinki (Finland)

    2014-07-01

    There are four operating nuclear power plant units in Finland at two separate locations. The units started operation during 1977-1980. The surveillance of radioactive substances in the vicinities of the nuclear power plant is carried out under the permanent monitoring programs. Some 1000 samples are taken annually from the surroundings of the power plants to confirm that the discharges from the power plants are within permissible release limits and to monitor the dispersion of discharges in the environment. Aquatic indicator organisms (macro-algae, periphyton, mussels, crustacean, submerged aquatic plants) are included in the monitoring program. The indicator organisms are valuable monitoring objects both in normal and emergency situations because they accumulate effectively and often very rapidly radioactive substances from the medium. Six different species (Periphyton, Fucus vesiculosus, Myriophyllum spicatum, Potamogeton pectinatus, Saduria entomon, Macoma Baltica/Mytilus edulis) are collected regularly. Number of sampling location for each species varies from 1 to 7. Some species are collected continuously, some 1-2 times in a year. In this study we have evaluated the monitoring results for the aquatic indicator organisms for the period of 2005-2010 concerning concentration of discharge nuclides. Our aim was to answer the following questions using the monitoring data from aquatic organisms: 1) Which radionuclides are released to the marine environment and how often do we detect them? 2) How far from the nuclear power plants discharge radionuclides are detected? 3) How concentration of discharge radionuclides has changed with time in aquatic organisms? The number of discharge nuclides detected in the aquatic indicator samples was 11. Most of them were only detected in few samples, but {sup 58}Co, {sup 60}Co, {sup 54}Mn and {sup 110m}Ag were detected more frequently. Most of the observations above detection limits were made within the 5 km distance from the

  14. Aquatic indicator organisms as a tool to monitor discharges from nuclear power plants

    International Nuclear Information System (INIS)

    There are four operating nuclear power plant units in Finland at two separate locations. The units started operation during 1977-1980. The surveillance of radioactive substances in the vicinities of the nuclear power plant is carried out under the permanent monitoring programs. Some 1000 samples are taken annually from the surroundings of the power plants to confirm that the discharges from the power plants are within permissible release limits and to monitor the dispersion of discharges in the environment. Aquatic indicator organisms (macro-algae, periphyton, mussels, crustacean, submerged aquatic plants) are included in the monitoring program. The indicator organisms are valuable monitoring objects both in normal and emergency situations because they accumulate effectively and often very rapidly radioactive substances from the medium. Six different species (Periphyton, Fucus vesiculosus, Myriophyllum spicatum, Potamogeton pectinatus, Saduria entomon, Macoma Baltica/Mytilus edulis) are collected regularly. Number of sampling location for each species varies from 1 to 7. Some species are collected continuously, some 1-2 times in a year. In this study we have evaluated the monitoring results for the aquatic indicator organisms for the period of 2005-2010 concerning concentration of discharge nuclides. Our aim was to answer the following questions using the monitoring data from aquatic organisms: 1) Which radionuclides are released to the marine environment and how often do we detect them? 2) How far from the nuclear power plants discharge radionuclides are detected? 3) How concentration of discharge radionuclides has changed with time in aquatic organisms? The number of discharge nuclides detected in the aquatic indicator samples was 11. Most of them were only detected in few samples, but 58Co, 60Co, 54Mn and 110mAg were detected more frequently. Most of the observations above detection limits were made within the 5 km distance from the nuclear power plants

  15. Boron in Pariette Wetland Sediments, Aquatic Vegetation & Benthic Organisms

    Science.gov (United States)

    Vasudeva, P.; Jones, C. P.; Powelson, D.; Jacobson, A. R.

    2015-12-01

    The Pariette Wetlands are comprised of 20 ponds located in Utah's Uintah Basin. Boron concentration in the Pariette Wetlands have been observed to exceed the total maximum daily limit of 750 µg L-1. Considering water flow in and out of the wetlands, boron is accumulating within the wetlands where it is sorbed to sediments and bioconcentrated by wetland plant and macro invertebrates. Since boron is an avian teratogen, an estimate of boron ingestion exposure is warranted. Samples from 3 of the 23 Pariette Wetland ponds with one pond near the inlet, one near the outlet, and one in the middle were collected. Five sampling points were designated along a 100 m transect of each pond. At each sampling point duplicate (or triplicate) samples of water, sediments, benthic organisms and wetland vegetation were collected. The sediments were collected with a KB-corer and divided at depths of 0-2 cm, 2-7 cm, and 7+ cm from the sediment surface. Sample splits were sent to the USU Bug lab for identification of invertebrate species. Whenever this transect was not intercepting vegetation, 2-3 additional sample sites were identified at the pond within stands of representative vegetation where bird nests are located. The plant parts used for boron analyses will include seeds, shoot and roots of vascular plants, as well as algae or duckweeds skimmed from the surface. Samples were processed within 2 days of collection. Water samples filtered through a 0.45 μ membrane filter were analyzed for DOC, pH and ECe. The dried and washed vegetation samples were ground and stored. The benthic organisms and macro invertebrates were netted at the water surface. The dried samples were weighed, ground and stored. Samples were weighed, oven dried and reweighed. For plant and macro-invertebrate samples, a nitric and hydrogen peroxide digestion procedure is used to dissolve environmentally available elements. The Hot Water extraction and DTPA-Sorbitol extraction were compared to estimate wetland plant

  16. Fractionation and characterization of soil organic carbon during transition to organic farming

    Science.gov (United States)

    Abdelrahman, H.; Olk, D.; Cocozza, C.; Miano, T.

    2012-04-01

    The transition from conventional to organic farming is the most difficult period faced by organic growers as it could be characterized by unstable conditions, such as nutrient availability, production reductions, mineralization extents. As soil organic matter (SOM), specifically soil organic carbon (SOC), is known to play important roles in maintenance and improvement of many soil properties, it is important to define its changes during the transition period. Total SOC might not be the suitable tool to track the changes in organically based soil fertility within a 3- to 5-yr transition period. Labile fractions that are important for nutrient cycling and supply are likely to be controlled by management to a much greater extent than is total SOM. Two field experiments, in south of Italy, were established in 2009 to study the changes in SOC during transition to organic farming. Experiments included a cereal/leguminous rotation with triplicates treatments of permitted amendments (compost and fertilizers). Soils were sampled at the beginning of the project, and after each crop harvest in 2010 and 2011. A sequential fractionation procedure was used to separate different SOC-fractions: light fraction (LF), two size classes of particulate organic matter (POM), mobile humic acid (MHA) and Ca++ bound humic acid (CaHA). Isolated fractions were quantified and analyzed for their content of C, N, carbohydrates and amino compounds fingerprints. The obtained results showed that compost application contributed to significantly higher quantities of LF, POM and MHA than did fertilizers application. Carbohydrates content decreased in LF while increased noticeably in POM and slightly in MHA fractions, which indicates that decomposing materials are converted, within the time span of humification, from young fractions into more mature fractions. Amino compounds were found to provide up to 40% of total soil N with a major contribution of the humified fractions, MHA and CaHA. The utilized

  17. Fingerprint of fractional charge transfer at metal/organic interface

    OpenAIRE

    Savu, Sabine-A.; Biddau, Giulio; Pardini, Lorenzo; Bula, Rafael; Bettinger, Holger F; Draxl, Claudia; Chassé, Thomas; Casu, M. Benedetta

    2015-01-01

    Although physisorption is a widely occurring mechanism of bonding at the organic/metal interface, contradictory interpretations of this phenomenon are often reported. Photoemission and X-ray absorption spectroscopy investigations of nanorods of a substituted pentacene, 2,3,9,10-tetrafluoropentacene, deposited on gold single crystals reveal to be fundamental to identify the bonding mechanisms. We find fingerprints of a fractional charge transfer from the clean metal substrate to the physisorbe...

  18. Temperature sensitivity of decomposition of soil organic carbon fractions

    Science.gov (United States)

    Hilasvuori, Emmi; Järvenpää, Marko; Akujärvi, Anu; Arppe, Laura; Christensen, Bent T.; Fritze, Hannu; Kaasalainen, Mikko; Karhu, Kristiina; Oinonen, Markku; Palonen, Vesa; Pitkänen, Juha-Matti; Repo, Anna; Vanhala, Pekka; Liski, Jari

    2015-04-01

    Knowing the temperature sensitivity of soil organic matter (SOM) decomposition is important for estimating the release of carbon from soil to the atmosphere in response to global warming. This temperature sensitivity is known relatively well for the most labile SOM fractions but still quite poorly for more recalcitrant fractions that represent the great majority of SOM. We report results for the temperature sensitivity of various SOM fractions in two different experiments in which we utilized natural abundances of carbon isotopes 13C and 14C combined with Bayesian mathematical modelling. In one experiment, the different age fractions were distinguished based on depth in a peat profile. In the other experiment, the age fractions were separated based on a time series of conversion from C3 vegetation to C4 vegetation. In both experiments, the temperature sensitivity of the SOM fractions was estimated by measuring the carbon isotope composition of heterotrophic soil respiration at different temperatures in laboratory. The results from these experiments suggest that the temperature sensitivity of unprotected SOM fractions increases with age, but if an environmental factor, such as bonding to soil minerals, limits decomposition of a SOM fraction, the temperature sensitivity is reduced. Our results are in agreement with the theory that suggests that in soil without environmental, physical or chemical protection, temperature sensitivity of carbon compounds is mainly determined by its chemical structure. The more complex the structure is the higher activation energy is needed and the higher its temperature sensitivity. Since SOM enriches with more complicated carbon compounds with time, this leads to increase in temperature sensitivity as SOM ages. However, our results also indicate that if the soil carbon is associated with minerals it might exhibit lower temperature sensitivities than when the carbon is "free" in the soil. Since the mineral associated carbon can have high

  19. Ecotoxicological assays of Diethyltoluamide and Lemongrass Essencial Oil in irradiated and non-irradiated aquatic organisms

    Energy Technology Data Exchange (ETDEWEB)

    Gimiliani, Giovana T.; Rogero, Sizue O.; Martini, Gisela A.; Rogero, Jose R., E-mail: sorogero@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    Aquatic invertebrates can be potentially exposed to nonradioactive contaminants in conjunction with ionizing radiation, especially in highly industrialized areas surrounding nuclear facilities, where radionuclides can accidentally be discharged in the aquatic environment containing stable chemicals. The aquatic organisms have continually been exposed to chemical contaminants like personal care products (PCPs) which have been found in various environmental matrices and may cause adverse effects to aquatic life and human health as radioactive products. In this study was used C. silvestrii as bioindicator organism in chronic ecotoxicity assays with lemongrass essencial oil (LEO) and Diethyltoluamide (DEET), both are insect repellent. In addition to exposition of the compounds, the organisms were irradiated with gamma rays from Co-60 source. Thus, the aim of this study was to evaluate the possible synergistic effect of gamma radiation and mosquito repellent products in the reproduction of Ceriodaphnia silvestrii utilizing standardized ecotoxicological tests. The C. silvestrii inhibition concentration (IC25; 7 days) result after DEET exposition was 16.4 ± 1.4 mg L{sup -1} and for LEO was 3.1 ± 1.4 mg L{sup -1}. In the irradiated (25 Gy) C. silvestrii exposed to DEET and LEO, the concentration that inhibited reproduction was 16.1 ± 0.9 mg L{sup -1} and 2.4 ± 0.3 mg L{sup -1} respectively. The results showed that the reproduction of irradiated C. silvestrii was not significantly affected when compared with non-irradiated organisms when exposed to DEET or LEO. (author)

  20. Natural and active chemical remediation of toxic metals, organics, and radionuclides in the aquatic environment

    Energy Technology Data Exchange (ETDEWEB)

    McPherson, G.; Pintauro, P.; O`Connor, S. [and others

    1996-05-02

    This project focuses on the chemical aspects of remediation, with the underlying theme that chemical remediation does occur naturally. Included are studies on the fate of heavy metal and organic contaminants discharged into aquatic environments; accurate assay metal contaminants partitioned into soils, water and tissue; development of novel polymeric membranes and microporous solids for the entrapment of heavy metals; and the development of hybrid chemo-enzymatic oxidative schemes for aromatics decontamination. 49 refs.

  1. Influence of Lipophilicity on the Toxicity of Bisphenol A and Phthalates to Aquatic Organisms.

    Science.gov (United States)

    Mathieu-Denoncourt, Justine; Wallace, Sarah J; de Solla, Shane R; Langlois, Valerie S

    2016-07-01

    Bisphenol A (BPA) and phthalates are among the most popular plasticizers used today and have been reported ubiquitously in surface water, ground water, and sediment. For aquatic organisms, BPA was the most toxic (96 h LC50s) to aquatic invertebrates (0.96-2.70 mg/L) and less toxic to fish (6.8-17.9 mg/L). The toxicity of BPA to amphibians differed among developmental stages, with embryos having an LC50 of 4.6-6.8 mg/L and juveniles 0.50-1.4 mg/L. The toxicity of phthalates is affected by aromatic ring substitution, alkyl chain length, and metabolism. The toxicity (96 h LC50s) of phthalates was similar to aquatic invertebrates (0.46-377 mg/L) and fish (0.48-121 mg/L). In general, the toxicity of phthalates appears to be highest around a log KOW of 6, which corresponds to the highest potential for bioconcentration and bioaccumulation. In conclusion, the lipophilicity of BPA and phthalates influence their toxicity to aquatic species.

  2. Effect of organic fractions on sorption properties of organic pollutants in sediments

    Institute of Scientific and Technical Information of China (English)

    CHEN Hua-lin; ZHOU Jiang-min; CHEN Ying-xu; XU Yun-tai

    2005-01-01

    Humic substrates are a major fraction of sediment organic matters, and the sorption of hydrophobic organic chemicals by humic substrates influences their behavior and fate in sediment. In this paper, organic matters were divided into non-humic substrates and humic substrates. Non-humic substrates include acid leaching fraction, acid extracted fraction, and lipid; humic substrates were fractionated into Ca-binding-FA(fulvic acid), Ca-binding-HA (humic acid), oxide-FA, oxide-HA, and humin. To study the effect of organic fractions on sorption properties, sorption kinetic and equilibrium sorption experiments of phenanthrene and pentachlorophenol(PCP) in five sediments were carried out. The results showed that the contents of acid leaching fraction and oxide-binding-HA were the main fractions to affect the sorption rate constant, and for the sorption capacity of phenanthrene, humin was the major fraction, followed by oxide-binding-HA, oxidebinding-FA, and so on. While for PCP, the factors of influence on sorption capacity were mainly CEC, Ca-binding-FA, and Ca-bindingHA.

  3. Evaluation of the aquatic toxicity of two veterinary sulfonamides using five test organisms.

    Science.gov (United States)

    De Liguoro, Marco; Di Leva, Vincenzo; Gallina, Guglielmo; Faccio, Elisabetta; Pinto, Gabriele; Pollio, Antonino

    2010-10-01

    The aquatic toxicity of sulfaquinoxaline (SQO) and sulfaguanidine (SGD) was evaluated on the following test organisms: Daphnia magna (reproduction test), Pseudokirchneriella subcapitata, Scenedesmus dimorphus, Synecococcus leopoliensis (algal growth inhibition test) and Lemna gibba (duckweed growth inhibition test). Furthermore, the additivity of the two compounds was measured on D. magna (acute immobilisation test) and P. subcapitata (algal growth inhibition test) using the isobologram method. Results show that SQO and SGD are more toxic to green algae and daphnids, respectively, than other veterinary sulfonamides (SAs) and that their mixtures have a less then additive interaction. Taking into account the highest concentrations detected so far in surface waters for SQO (0.112 μg L(-1)) and for SGD (0.145 μg L(-1)) and the lowest NOECs obtained with the five test organisms, divided by an assessment factor of 10, the following PNECs and risk quotients (RQs) were calculated. SQO: PNEC 2 μg L(-1); RQ 0.056. SGD: PNEC 39.5 μg L(-1); RQ 0.004. Consequently, at the concentrations actually detected in the aquatic environment, the two SAs alone should not harm the freshwater organisms. However, it seems advisable, for veterinary mass treatments, the use of other SAs that have a lesser impact on the aquatic environment. Furthermore, considering the high probability of having complex mixtures of different SAs residues in water, each individual contamination should be evaluated by applying to the SAs mixtures the conservative criteria of additivity. PMID:20673955

  4. Species and biogeochemical cycles of organic phosphorus in sediments from a river with different aquatic plants located in Huaihe River Watershed, China.

    Science.gov (United States)

    Yuan, He Zhong; Pan, Wei; Ren, Li Jun; Liu, Eeng Feng; Shen, Ji; Geng, Qi Fang; An, Shu Qing

    2015-01-01

    The results of phosphorus fractionation in the sediments from a contaminated river containing different aquatic plants, analyzed by solution 31P-NMR for Organic Phosphorus, showed that the concentration of Inorganic Phosphorus dominated in all species and Organic Phosphorus accounted for over 20% of Total Phosphorus. In general, orthophosphate was dominant in all the sampling sites. The proportion of Organic Phosphorus accounting for the Total Phosphorus in the sediments with different plant decreased in the following order: Paspalum distichum>Typha orientalis>Hydrilla verticillata. Phosphorus-accumulation ability of Paspalum distichum was obviously stronger than Typha orientalis and Hydrilla verticillata. The Organic Phosphorus was in aquatic plants dominated by humic-associated P (Hu-P), which converted to Inorganic Ohosphorus more significantly in submerged plants than in emerged plants. The sediment dominated by Paspalum distichum abundantly accumulated Organic Phosphorus in the orthophosphate monoester fraction. The degradation and mineralization of orthophosphate monoester was the important source of high Inorganic Phosphorus concentration and net primary productivity in Suoxu River. The Organic Phosphorus derived from Typha orientalis and Hydrilla verticillata was dramatically converted to Inorganic Phosphorus when the environmental factors varied.

  5. Mosquitocidal essential oils: are they safe against non-target aquatic organisms?

    Science.gov (United States)

    Conti, Barbara; Flamini, Guido; Cioni, Pier Luigi; Ceccarini, Lucia; Macchia, Mario; Benelli, Giovanni

    2014-01-01

    In latest years, the importance of the Melaleuca alternifolia essential oil (EO) has been greatly empathised due to its anti-microbial and anti-inflammatory effects, as well as to its toxic properties towards many arthropods of great medical and veterinary importance. In this research, the EO extracted from aerial parts of M. alternifolia was evaluated for its toxicity against larvae of the most invasive mosquito worldwide, Aedes albopictus (Diptera: Culicidae), and towards adults of the water flea, Daphnia magna (Cladocera: Crustacea), a non-target aquatic organism that share the same ecological niche of A. albopictus. The chemical composition of M. alternifolia EO was investigated by GC-MS analysis. Tea tree EO was mainly composed by oxygenated monoterpenes, with 1,8-cineole as the major constituent. M. alternifolia EO exerted toxic activity against A. albopictus larvae, with a LC50 = 267.130 ppm. However, this EO had a remarkable acute toxicity also towards adults of the non-target arthropod D. magna, with a LC50 = 80.636 ppm. This research provide useful information for the development of newer and safer mosquito control tools, highlighting that the non-target effects against aquatic organisms that share the same ecological niche of A. albopictus larvae are crucial in the development of ecofriendly mosquito control strategies. Further research is needed to investigate the chronic and/or reproductive toxicity of M. alternifolia EO both towards target and non-target aquatic arthropods.

  6. Pressure of non-professional use of pesticides on operators, aquatic organisms and bees in Belgium.

    Science.gov (United States)

    Fevery, Davina; Houbraken, Michael; Spanoghe, Pieter

    2016-04-15

    Various studies focus on professional pesticide use, whereas pressure of non-professional use on human and the environment is often neglected. In this study, an attempt was made to estimate the pressure of non-professional use of pesticides on operators, aquatic organisms and bees in Belgium based on sales figures and by using three exposure models. A classification in non-professional use was made based on type of pesticide, application method and on intensity of non-professional use. Pressure of non-professional use on operators is highest for intensive operators, caused by the use of insecticides in an aerosol spray can. Pressure of non-professional pesticides on aquatic life is mainly generated by the use of herbicides. The aerosol spray induces the highest pressure whereas the trigger application hardly affects operator and environmental exposure. The ordinary non-professional user generates most pressure on aquatic organisms. Pressure of non-professional pesticides on bees is mainly caused by the use of insecticides, especially the active substance imidacloprid in combination with the aerosol spray can application method applied by an intensive operator. In general, both total usage (kg) and pressure of pesticides decreased for the period 2005 to 2012 due to efforts made by the government and industry. The results of this study suggest to pay special attention to aerosol spray applications and the non-professional use of insecticides.

  7. Review of reproductive and developmental toxicity induced by organotins in aquatic organisms and experimental animals

    Energy Technology Data Exchange (ETDEWEB)

    Hirose, A.; Takagi, A.; Nishimura, T.; Kanno, J.; Ema, M. [National Inst. of Health Sciences, Tokyo (Japan)

    2004-09-15

    Widespread use of organotins has caused increasing amounts to be released into the environment. The most important non-pesticidal route of entry of organotins into the environment is through leaching of organotin-stabilized PVC in water, and the use in antifouling agents, resulting in the introduction of organotin into the aquatic environment. Data are available regarding the detection of butyltins and phenyltins in aquatic marine organisms and marine products. Food chain bioamplification of butyltin in oysters, mud crabs, marine mussels, chinook salmons, dolphins, tunas, and sharks and of phenyltin in carps and horseshoe crabs has been reported. These findings indicate that organotins accumulate in the food chain and are bioconcentrated, and that humans can be exposed to organotins via seafood. The levels of organotin compounds in seafood are not considered to be sufficiently high to affect human health. However, Belfroid et al. (2000) noted that more research on residual TBT levels in seafood was needed before a definitive conclusion on possible health risks could be drawn. Although the toxicity of organotins has been extensively reviewed, the reproductive and developmental toxicity of organotins is not well understood. We summarized the data of the studies on reproductive and developmental toxicity of organotins in aquatic organisms and experimental animals.

  8. The mysteriously variable half-life of dissolved organic matter in aquatic ecosystems: artefact or insight?

    Science.gov (United States)

    Evans, Chris; Fovet, Ophelie; Jones, Tim; Jones, Davey; Moldan, Filip; Futter, Martyn

    2016-04-01

    Dissolved organic matter (DOM) fluxes from land to water represent an important loss term in the terrestrial carbon balance, a major pathway in the global carbon cycle, a significant influence on aquatic light, nutrient and energy regimes, and an important concern for drinking water production. Although freshwaters are now recognised as zones of active carbon cycling, rather than passive conduits for carbon transport, evidence regarding the magnitude of, and controls on, DOM cycling in aquatic systems is incomplete and in some cases seemingly contradictory, with DOM 'half-lives' ranging from a few days to many years. Bringing together experimental, isotopic, catchment mass balance and modelling data, we suggest that apparently conflicting results can be reconciled through understanding of differences in: i) the terrestrial sources of DOM within heterogeneous landscapes, and consequent differences in its reactivity and stoichiometry; ii) experimental methodologies (i.e. which reactions are actually being measured), and iii) the extent of prior transformation of DOM upstream of the point of study. We argue that rapid photo-degradation, particularly of peat-derived DOM, is a key process in headwaters, whilst apparently slow DOM turnover in downstream, agriculturally-influenced lakes and rivers can partly be explained by the offsetting effect of in situ DOM production. This production appears to be strongly constrained by nutrient supply, thus linking DOM turnover and composition to the supply of inorganic nutrient inputs from diffuse agricultural pollution, and also providing a possible mechanistic link between aquatic DOM production and terrestrial DOM breakdown via the mineralisation and re-assimilation of organic nutrients. A more complete conceptual understanding of these interlinked processes will provide an improved understanding of the sources and fate of aquatic DOM, its role in the global carbon cycle, and the impact of anthropogenic activities, for example

  9. Fouling of nanofiltration membrane by effluent organic matter: characterization using different organic fractions in wastewater

    Institute of Scientific and Technical Information of China (English)

    ZHANG Liqing; WANG Lei; ZHANG Gang; WANG Xudong

    2009-01-01

    The UF membrane with molecular weight cutoff (MWCO) ranging from 2 kDa to 100 kDa and XAD-8 resin were employed to identify the characteristic of molecular weight (MW) distribution of wastewater effluent organic matter (EfOM) in terms of TOC and UV254, as well as the amounts of the hydrophilic/hydrophobic organic fractions in different MW ranges. Then, the nanofiltration (NF) membrane fouling experiments were carried out using the above fractionated water to investigate the effect of MW distribution and hydrophilic/hydrophobic characteristics of EfOM on the membrane flux decline using the fractionated water samples above. The experimental results have shown that 45.61% of the total organics belongs to the low MW one, among which the percentage of the hydrophilic organics with low MW (less than 2 kDa) was up to 28.07%, while that of the hydrophobic organics was 17.54%. In particular, the hydrophilic fraction was found to be the most abundant fraction in the effluents. MW distribution has a significant effect on the membrane fouling. When the MW was less than 30 kDa, the lower the MW, the larger was the specific flux decline, while in the case of MW higher than 30 kDa, the higher the MW, the larger was the specific flux decline, and the decline degree of low MW organics was larger than the high MW one. With the same MW distribution range, specific flux decline of the hydrophilic organic was considerably slower than that of the hydrophobic organic, which indicated that the hydrophobic organic fractions dominantly contribute to the flux decline.

  10. Ecological risk assessment for aquatic organisms from over-water uses of glyphosate.

    Science.gov (United States)

    Solomon, Keith R; Thompson, Dean G

    2003-01-01

    Although the herbicide glyphosate is most widely used in agriculture, some is used for the control of emergent aquatic weeds in ditches, wetlands, and margins of water bodies, largely as the formulation Rodeo. This article presents an ecological risk assessment (ERA) of glyphosate and some of the recommended surfactants as used in or near aquatic systems. Glyphosate does not bioaccumulate, biomagnify, or persist in a biologically available form in the environment. Its mechanism of action is specific to plants and it is relatively nontoxic to animals. As a commercial product, glyphosate may be formulated with surfactants that increased efficacy but, in some cases, are more toxic to aquatic organisms than the parent material. For this risk assessment, three model exposure scenarios--static or low-flow systems such as ponds, flowing waters such as streams, and systems subjected to tidal flows such as estuaries--were chosen and application rates from 1 to 8 kg glyphosate/ha were modeled. Additional measured exposure data from several field studies were also used. As acute exposures are most likely to occur, acute toxicity data were used as effect measures for the purposes of risk assessment. Toxicity data were obtained from the literature and characterized using probabilistic techniques. Risk assessments based on estimated and measured concentrations of glyphosate that would result from its use for the control of undesirable plants in wetlands and over-water situations showed that the risk to aquatic organisms is negligible or small at application rates less than 4 kg/ha and only slightly greater at application rates of 8 kg/ha. Less is known about the environmental fate and toxicology of the surfactants commonly used in combination with the Rodeo formulation of glyphosate. The surfactants used for this purpose were judged not to be persistent nor bioaccumulative in the environment. Distributional analysis of measured deposition concentrations of LI 700, suggest that

  11. Enhanced characterization of oil sands acid-extractable organics fractions using electrospray ionization-high-resolution mass spectrometry and synchronous fluorescence spectroscopy.

    Science.gov (United States)

    Bauer, Anthony E; Frank, Richard A; Headley, John V; Peru, Kerry M; Hewitt, L Mark; Dixon, D George

    2015-05-01

    The open pit oil sands mining operations north of Fort McMurray, Alberta, Canada, are accumulating tailings waste at a rate approximately equal to 4.9 million m(3) /d. Naphthenic acids are among the most toxic components within tailings to aquatic life, but structural components have largely remained unidentified. In the present study, electrospray ionization high-resolution mass spectrometry (ESI-HRMS) and synchronous fluorescence spectroscopy (SFS) were used to characterize fractions derived from the distillation of an acid-extractable organics (AEO) mixture isolated from oil sands process-affected water (OSPW). Mean molecular weights of each fraction, and their relative proportions to the whole AEO extract, were as follows: fraction 1: 237 Da, 8.3%; fraction 2: 240 Da, 23.8%; fraction 3: 257 Da, 26.7%; fraction 4: 308 Da, 18.9%; fraction 5: 355 Da, 10.0%. With increasing mean molecular weight of the AEO fractions, a concurrent increase occurred in the relative abundance of nitrogen-, sulfur-, and oxygen-containing ions, double-bond equivalents, and degree of aromaticity. Structures present in the higher-molecular-weight fractions (fraction 4 and fraction 5) suggested the presence of heteroatoms, dicarboxyl and dihydroxy groups, and organic acid compounds with the potential to function as estrogens. Because organic acid compositions become dominated by more recalcitrant, higher-molecular-weight acids during natural degradation, these findings are important in the context of oil sands tailings pond water remediation. PMID:25615406

  12. Multi-Elemental Inductively Coupled Plasma-Optical Emission Spectroscopic Calibration Problems of the Sequential Extraction Procedure for the Fractionation of the Heavy Metal Content from Aquatic Sediments

    OpenAIRE

    Heltai György; Fekete Ilona; Halász Gábor; Kovács Katalin (1978-) (biokémikus); Horváth Márk; Takács Anita; Boros Norbert; Győri Zoltán (1948-) (vegyész)

    2015-01-01

    For the characterisation of the environmental mobility of heavy metal contamination in aquatic sediments, the EU Bureau of Reference has proposed a fractionation by sequential extraction procedure. For its validation, the CRM-701 sample is available containing Cd, Cr, Cu, Ni, Pb, and Zn. In this paper, the matrix-matched calibration problems are presented. A multi-elemental inductively coupled plasma-optical emission technique is employed for the detection of heavy metals in the extracts. It ...

  13. Assessing exposure risks for aquatic organisms posed by Tamiflu use under seasonal influenza and pandemic conditions

    International Nuclear Information System (INIS)

    Environmental pollution by anti-influenza drugs is increasingly recognized as a threat to aquatic environments. However, little is known about empirical data on risk effects posed by environmentally relevant concentrations of anti-influenza drug based on recently published ecotoxicological researches in Taiwan. Here we linked ecotoxicology models with an epidemiological scheme to assess exposure risks of aquatic organisms and environmental hazards posed by antiviral oseltamivir (Tamiflu) use in Taiwan. Built on published bioassays, we used probabilistic risk assessment model to estimate potential threats of environmentally relevant hazards on algae, daphnid, and zerbrafish. We found that Tamiflu use was unlikely to pose a significant chronic environmental risk to daphnia and zebrafish during seasonal influenza. However, the chronic environmental risk posed by Tamiflu use during pandemic was alarming. We conclude that no significant risk to algal growth was found during seasonal influenza and high pandemic Tamiflu use. -- Highlights: • Environmentally relevant concentrations of anti-influenza drug have ecotoxicologically important effects. • Tamiflu is unlikely to pose a significant chronic environmental risk during seasonal influenza. • Chronic environmental risk posed by Tamiflu during pandemic is alarming. • Tertiary process in sewage treatment plants is crucial in mitigating Tamiflu exposure risk. -- A probabilistic framework can be used for assessing exposure risks posed by environmentally relevant concentrations of anti-influenza drug in aquatic ecosystems

  14. Design and setup of intermittent-flow respirometry system for aquatic organisms

    DEFF Research Database (Denmark)

    Svendsen, Morten Bo Søndergaard; Bushnell, P.G.; Steffensen, John Fleng

    2016-01-01

    software further reduces error by allowing many measurements to be made over long periods thereby minimizing animal stress due to acclimation issues. This paper describes some of the fundamental principles that need to be considered when designing and carrying out automated intermittent-flow respirometry......Intermittent-flow respirometry is an experimental protocol for measuring oxygen consumption in aquatic organisms that utilizes the best features of closed (stop-flow) and flow-through respirometry while eliminating (or at least reducing) some of their inherent problems. By interspersing short...

  15. Thermal effects on aquatic organisms: an annotated bibliography of the 1977 literature

    International Nuclear Information System (INIS)

    This bibliography, containing 537 references from the 1977 literature, is the seventh in a series of annotated bibliographies on the effects of heat on aquatic organisms. The effects of thermal discharges at power plant sites are emphasized. Laboratory and field studies on temperature tolerance and the effects of temperature changes on reproduction, development, growth, distribution, physiology, and sensitivity to other stresses are included. References in the bibliography are divided into three subject categories: marine systems, freshwater systems, and estuaries. The references are arranged alphabetically by first author. Indexes are provided for author, keywords, subject category, geographic location of the study, taxon, and title

  16. Acute Toxicity of Double-Walled Carbon Nanotubes to Three Aquatic Organisms

    Directory of Open Access Journals (Sweden)

    Lungile P. Lukhele

    2015-01-01

    Full Text Available This study investigated the toxicity of double walled carbon nanotubes (DWCNTs to three aquatic organisms, namely, Pseudokirchneriella subcapitata, Daphnia pulex, and Poecilia reticulata under the influence of exposure media properties specifically the ionic strength and organic matter represented by humic acid. Results indicated that ionic strength enhanced DWCNTs agglomeration whilst humic acid stabilized the CNTs and in turn inhibited the formation of aggregates. LC50s for D. pulex were higher at 2.81 and 4.45 mg/L for pristine and oxidised DWCNTs, respectively; however, P. reticulata had lower values of 113.64 mg/L and 214.0 mg/L for the same CNTs correspondingly. P. subcapitata had EC50s of 17.95 mg/L and 10.93 mg/L for the pristine and oxidised DWCNTs, respectively. In the presence of humic acid high DWCNTs acute toxicity towards D. pulex and P. reticulata was observed but ionic strength led to opposite effect irrespective of DWCNTs form. Both humic acid and ionic strength shielded the P. subcapitata from toxic effects of DWCNTs. Overall, our findings suggest that the toxicity of DWCNTs in the aquatic systems (i will be dependent on media properties and (ii is likely to proceed at different rates to organisms at different trophic levels.

  17. Organic chemistry of Murchison meteorite: Carbon isotopic fractionation

    Science.gov (United States)

    Yuen, G. U.; Blair, N. E.; Desmarais, D. J.; Cronin, J. R.; Chang, S.

    1986-01-01

    The carbon isotopic composition of individual organic compounds of meteoritic origin remains unknown, as most reported carbon isotopic ratios are for bulk carbon or solvent extractable fractions. The researchers managed to determine the carbon isotopic ratios for individual hydrocarbons and monocarboxylic acids isolated from a Murchison sample by a freeze-thaw-ultrasonication technique. The abundances of monocarboxylic acids and saturated hydrocarbons decreased with increasing carbon number and the acids are more abundant than the hydrocarbon with the same carbon number. For both classes of compounds, the C-13 to C-12 ratios decreased with increasing carbon number in a roughly parallel manner, and each carboxylic acid exhibits a higher isotopic number than the hydrocarbon containing the same number of carbon atoms. These trends are consistent with a kinetically controlled synthesis of higher homologues for lower ones.

  18. Controlling and maintaining exposure of hydrophobic organic compounds in aquatic toxicity tests by passive dosing

    International Nuclear Information System (INIS)

    The risk assessment of hydrophobic organic compounds (HOCs) in aquatic toxicity or bioconcentration tests is a challenge due to their low aqueous solubilities, sorption and losses leading to poorly defined exposure and reduced test sensitivity. Passive dosing overcomes these problems via the continual partitioning of HOCs from a dominating reservoir loaded in a biocompatible polymer such as silicone, providing defined and constant freely dissolved concentrations and eliminating spiking with co-solvents. This study characterised the performance of a passive dosing format for aquatic tests with small organism such as invertebrates and algae, consisting of PDMS silicone cast into the base of the glass test vessel. The PDMS silicone was loaded by partitioning from a methanol solution containing PAHs (log KOW 3.56-6.63) as model compounds, followed by removal of the methanol with water. This resulted in highly reproducible PDMS silicone HOC concentrations. When shaking, release of PAHs into aqueous solution was rapid and reproducible, and equilibrium partitioning was reached within 5 h for all compounds. The buffering capacity was sufficient to maintain stable concentrations over more than 10 weeks. This format was applied in a 48 h Daphnia magna immobilisation assay to test the toxicity of a range of PAHs at their aqueous solubility. D. magna immobilisation did not show a trend with aqueous solubility or hydophobicity (KOW) of the PAHs. However, the immobilisation data for all compounds could be fitted with one maximum chemical activity response curve. Those PAHs with the lowest maximum chemical activities resulted in no immobilisation. Naphthalene and phenanthrene showed full toxicity at aqueous solubility, and passive dosing was also used for the concentration-response testing of these compounds. The freely dissolved aqueous concentrations causing 50% immobilisation (EC-50) were 1.96 mg L-1 for naphthalene and 0.48 mg L-1 for phenanthrene. Therefore, passive dosing

  19. Toxicity of the veterinary sulfonamide antibiotic sulfamonomethoxine to five aquatic organisms.

    Science.gov (United States)

    Huang, Da-Ji; Hou, Jung-Hsin; Kuo, Tzong-Fu; Lai, Hong-Thih

    2014-11-01

    The purpose of this study was to investigate the acute and chronic toxicity of sulfamonomethoxine (SMM) to aquatic organisms to evaluate its impact at different trophic levels in the ecosystem. Regarding the growth inhibition of microalgae, SMM exhibited 72-h median effective concentration (EC50) values of 5.9mgL(-1) for freshwater Chlorella vulgaris and 9.7mgL(-1) for marine Isochrysis galbana. In a study on the cladocerans, SMM exhibited acute toxicity and 48-h median lethal concentrations of 48mgL(-1) for Daphnia magna and 283mgL(-1) for D. similis. An examination of chronic toxicity revealed that SMM inhibited the brook production of the cladocerans and exhibited 21-day EC50 values of 14.9mgL(-1) for D. magna and 41.9mgL(-1) for D. similis. This study investigated the potentially adverse effects of SMM on aquatic organisms and revealed that microalgae exhibited higher sensitivity to SMM than cladocerans did. The residue of SMM in water is recommended to be carefully evaluated to reduce ecological impacts after applied to cultured animals.

  20. Radioactive contamination of aquatic media and organisms; La contamination radioactive des milieux et des organismes aquatiques

    Energy Technology Data Exchange (ETDEWEB)

    Fontaine, Y. [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    After a brief account of the radioactive wastes produced by peaceful or military uses of Atomic Industry, the author first describes a series of observations carried out 'in the field' on the extent of contamination in aquatic organisms with respect to that of the medium. The experimental studies are then analysed, with reference both to the radioisotope metabolism and to the factors and types of contamination of aquatic organisms by wastes from atomic industry. A precise experimental project is presented at the end of the paper, including almost 300 references. (author) [French] Apres une courte etude des dechets radioactifs produits par les utilisations pacifiques ou militaires de l'Industrie Atomique, l'auteur fait etat d'abord des observations effectuees 'sur le terrain' concernant l'extension de la contamination des organismes aquatiques en rapport avec celle du milieu. L'auteur analyse ensuite les etudes experimentales se rapportant aussi bien au metabolisme des radioisotopes qu'aux facteurs et aux modalites de la contamination des organismes aquatiques par les dechets de l'industrie atomique. Un projet de travail experimental precis est presente a la fin de cette revue qui comporte pres de 300 references bibliographiques. (auteur)

  1. Application of the Activity Framework for Assessing Aquatic Ecotoxicology Data for Organic Chemicals

    DEFF Research Database (Denmark)

    Thomas, Paul; Dawick, James; Lampi, Mark;

    2015-01-01

    Toxicological research in the 1930s gave the first indications of the link between narcotic toxicity and the chemical activity of organic chemicals. More recently, chemical activity has been proposed as a novel exposure parameter that describes the fraction of saturation and that quantifies the p...

  2. Single and joint ecotoxicity data estimation of organic UV filters and nanomaterials toward selected aquatic organisms. Urban groundwater risk assessment.

    Science.gov (United States)

    Molins-Delgado, Daniel; Gago-Ferrero, Pablo; Díaz-Cruz, M Silvia; Barceló, Damià

    2016-02-01

    The hazardous potential of organic UV filters (UV-Fs) is becoming an issue of great concern due to the widespread application of these compounds in most daily-use goods, such as hygiene and beauty products. Nanomaterials (NMs) have also been used in personal care products (PCPs) for many years. Nowadays, both classes of chemicals are considered environmental emerging contaminants. Despite some studies performed in vitro and in vivo reported adverse effects of many UV-Fs on the normal development of organisms, there is scarce data regarding acute and chronic toxicity. The aim of the present study was to determine the EC50 values of selected UV-Fs using standardised toxicity assays on three aquatic species i.e. Daphnia magna, Raphidocelis subcapitata and Vibrio fischeri. EC50 values obtained were in the mgl(-1) range for all the species. The estimated toxicity data allowed us to assess the environmental risk posed by selected UV-Fs in urban groundwater from Barcelona (Spain). The calculated ecological risk indicated a negligible impact on the aquifer. Giving the increasing importance of studying mixtures of pollutants and due to the widespread presence of nanomaterials (NMs) in the aquatic environment, other objective of this work was to explore the response on D. magna after exposure to both binary combinations of UV-Fs among them and UV-F with NMs. In all cases but the nano-silver mixtures, joint toxicity was mitigated or even eradicated. PMID:26674115

  3. Mechanical biological treatment of organic fraction of MSW affected dissolved organic matter evolution in simulated landfill.

    Science.gov (United States)

    Salati, Silvia; Scaglia, Barbara; di Gregorio, Alessandra; Carrera, Alberto; Adani, Fabrizio

    2013-08-01

    The aim of this paper was to study the evolution of DOM during 1 year of observation in simulated landfill, of aerobically treated vs. untreated organic fraction of MSW. Results obtained indicated that aerobic treatment of organic fraction of MSW permitted getting good biological stability so that, successive incubation under anaerobic condition in landfill allowed biological process to continue getting a strong reduction of soluble organic matter (DOM) that showed, also, an aromatic character. Incubation of untreated waste gave similar trend, but in this case DOM decreasing was only apparent as inhibition of biological process in landfill did not allow replacing degraded/leached DOM with new material coming from hydrolysis of fresh OM. PMID:23743423

  4. Complexation of trace organic contaminants with fractionated dissolved organic matter: implications for mass spectrometric quantification.

    Science.gov (United States)

    Ruiz, Selene Hernandez; Wickramasekara, Samanthi; Abrell, Leif; Gao, Xiaodong; Chefetz, Benny; Chorover, Jon

    2013-04-01

    Interaction with aqueous phase dissolved organic matter (DOM) can alter the fate of trace organic contaminants of emerging concern once they enter the water cycle. In order to probe possible DOM binding mechanisms and their consequences for contaminant detection and quantification in natural waters, a set of laboratory experiments was conducted with aqueous solutions containing various operationally-defined "hydrophilic" and "hydrophobic" freshwater DOM fractions isolated by resin adsorption techniques from reference Suwannee River natural organic matter (SROM). Per unit mass of SROM carbon, hydrophobic acids (HoA) comprised the largest C fraction (0.63±0.029), followed by hydrophilic-neutrals (HiN, 0.11±0.01) and acids (HiA, 0.09±0.017). Aqueous solutions comprising 8mgL(-1) DOC of each SROM fraction were spiked with a concentration range (10-1000μgL(-1)) of bisphenol A (BPA), carbamazepine (CBZ), or ibuprofen (IBU) as model target compounds in 24mM NH4HCO3 background electrolyte at pH 7.4. Contaminant interaction with the SROM fractions was probed using fluorescence spectroscopy, and effects on quantitative analysis of the target compounds were measured using direct aqueous-injection liquid chromatography tandem mass spectrometry (LC-MS/MS). Total quenching was greater for the hydrophilic fractions of SROM and associations were principally with protein-like and fulvic acid-like constituents. Whereas LC-MS/MS recoveries indicated relatively weak interactions with most SROM factions, an important exception was the HiA fraction, which diminished recovery of CBZ and IBU by ca. 30% and 70%, respectively, indicating relatively strong molecular interactions. PMID:23276460

  5. Effects of Marine Toxins on the Reproduction and Early Stages Development of Aquatic Organisms

    Directory of Open Access Journals (Sweden)

    Vítor Ramos

    2010-01-01

    Full Text Available Marine organisms, and specially phytoplankton species, are able to produce a diverse array of toxic compounds that are not yet fully understood in terms of their main targets and biological function. Toxins such as saxitoxins, tetrodotoxin, palytoxin, nodularin, okadaic acid, domoic acid, may be produced in large amounts by dinoflagellates, cyanobacteria, bacteria and diatoms and accumulate in vectors that transfer the toxin along food chains. These may affect top predator organisms, including human populations, leading in some cases to death. Nevertheless, these toxins may also affect the reproduction of aquatic organisms that may be in contact with the toxins, either by decreasing the amount or quality of gametes or by affecting embryonic development. Adults of some species may be insensitive to toxins but early stages are more prone to intoxication because they lack effective enzymatic systems to detoxify the toxins and are more exposed to the toxins due to a higher metabolic growth rate. In this paper we review the current knowledge on the effects of some of the most common marine toxins on the reproduction and development of early stages of some organisms.

  6. Thermal effects on aquatic organisms: an annotated bibliography of the 1977 literature

    Energy Technology Data Exchange (ETDEWEB)

    Talmage, S.S. (comp.)

    1978-12-01

    This bibliography, containing 537 references from the 1977 literature, is the seventh in a series of annotated bibliographies on the effects of heat on aquatic organisms. The effects of thermal discharges at power plant sites are emphasized. Laboratory and field studies on temperature tolerance and the effects of temperature changes on reproduction, development, growth, distribution, physiology, and sensitivity to other stresses are included. References in the bibliography are divided into three subject categories: marine systems, freshwater systems, and estuaries. The references are arranged alphabetically by first author. Indexes are provided for author, keywords, subject category, geographic location of the study, taxon, and title (alphabetical listing of keywords-in-context of nontrivial words in the title).

  7. Manufactured nanoparticles in the aquatic environment-biochemical responses on freshwater organisms: A critical overview.

    Science.gov (United States)

    Vale, Gonçalo; Mehennaoui, Kahina; Cambier, Sebastien; Libralato, Giovanni; Jomini, Stéphane; Domingos, Rute F

    2016-01-01

    The enormous investments in nanotechnology have led to an exponential increase of new manufactured nano-enabled materials whose impact in the aquatic systems is still largely unknown. Ecotoxicity and nanosafety studies mostly resulted in contradictory results and generally failed to clearly identify biological patterns that could be related specifically to nanotoxicity. Generation of reactive oxygen species (ROS) is one of the most discussed nanotoxicity mechanism in literature. ROS can induce oxidative stress (OS), resulting in cyto- and genotoxicity. The ROS overproduction can trigger the induction of anti-oxidant enzymes such as catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidases (GPx), which are used as biomarkers of response. A critical overview of the biochemical responses induced by the presence of NPs on freshwater organisms is performed with a strong interest on indicators of ROS and general stress. A special focus will be given to the NPs transformations, including aggregation, and dissolution, in the exposure media and the produced biochemical endpoints.

  8. A Review of the Tissue Residue Approach for Organic and Organometallic Compounds in Aquatic Organisms

    Science.gov (United States)

    This paper reviews the tissue residue approach (TRA) for toxicity assessment as it applies to organic chemicals and some organometallic compounds (tin, mercury, and lead). Specific emphasis was placed on evaluating key factors that influence interpretation of critical body resid...

  9. Parametric Evaluation of Digestability of Organic Fraction of Municipal Solid Waste for Biogas Production

    OpenAIRE

    Monoj Kumar Mondal; Aparna Banerjee

    2015-01-01

    Municipal solid waste was collected from Varanasi’s municipal solid waste dumpsite and sorted for organic fraction present in it. Current work showed the consequences of calcium hydroxide or lime digestion on organic fraction of municipal solid waste of Varanasi, India. The organic fraction of municipal solid waste sample was digested with desired amount of calcium hydroxide. The different concentrations (0.1, 0.2, and 0.5 %) of calcium hydroxide was blended separately to substrates (10...

  10. Chain-Length Distribution and Hydrogen Isotopic Fraction of n-alkyl Lipids in Aquatic and Terrestrial Plants: Implications for Paleoclimate Reconstructions

    Science.gov (United States)

    Gao, L.; Littlejohn, S.; Hou, J.; Toney, J.; Huang, Y.

    2008-12-01

    Recent studies demonstrate that in lacustrine sediments, aquatic plant lipids (e.g., C22-fatty acid) record lake water D/H ratio variation, while long-chain fatty acids (C26-C32, major components of terrestrial plant leaf waxes), record D/H ratios of precipitation (especially in arid regions). However, there are insufficient literature data for the distribution and hydrogen isotopic fractionation of n-alkyl lipids in aquatic and terrestrial plants. In this study, we determined the chain-length distributions and D/H ratios of n-alkyl lipids from 17 aquatic plant species (9 emergent, 4 floating and 4 submerge species) and 13 terrestrial plant species (7 grasses and 6 trees) from Blood Pond, Massachusetts. Our results are consistent with previous studies and provide a solid basis for the paleoclimatic reconstruction using D/H ratios of aquatic and terrestrial plant biomarkers. In addition, systematic hydrogen isotopic analyses on leaf waxes, leaf, stem and soil waters from trees and grasses significantly advance our understanding of our previously observed large D/H ratio difference between tree and grass leaf waxes. Our data indicate that the observed difference is not due to differences in leaf water D/H ratios. In comparison with grasses, trees use greater proportion of D-enriched residual or stored carbohydrates (as opposed to current photosynthetic carbohydrates) for leaf wax biosynthesis, resulting in higher leaf wax D/H ratios. The residual carbohydrates are enriched in deuterium because of the preferential consumption of light-hydrogen substrates during plant metabolism.

  11. An in vitro screening with emerging contaminants reveals inhibition of carboxylesterase activity in aquatic organisms.

    Science.gov (United States)

    Solé, Montserrat; Sanchez-Hernandez, Juan C

    2015-12-01

    Pharmaceuticals and personal care products (PPCPs) form part of the new generation of pollutants present in many freshwater and marine ecosystems. Although environmental concentrations of these bioactive substances are low, they cause sublethal effects (e.g., enzyme inhibition) in non-target organisms. However, little is known on metabolism of PPCPs by non-mammal species. Herein, an in vitro enzyme trial was performed to explore sensitivity of carboxylesterase (CE) activity of aquatic organisms to fourteen PPCPs. The esterase activity was determined in the liver of Mediterranean freshwater fish (Barbus meridionalis and Squalius laietanus), coastal marine fish (Dicentrarchus labrax and Solea solea), middle-slope fish (Trachyrhynchus scabrus), deep-sea fish (Alepocephalus rostratus and Cataetix laticeps), and in the digestive gland of a decapod crustacean (Aristeus antennatus). Results showed that 100μM of the lipid regulators simvastatin and fenofibrate significantly inhibited (30-80% of controls) the CE activity of all target species. Among the personal care products, nonylphenol and triclosan were strong esterase inhibitors in most species (36-68% of controls). Comparison with literature data suggests that fish CE activity is as sensitive to inhibition by some PPCPs as that of mammals, although their basal activity levels are lower than in mammals. Pending further studies on the interaction between PPCPs and CE activity, we postulate that this enzyme may act as a molecular sink for certain PPCPs in a comparable way than that described for the organophosphorus pesticides. PMID:26562051

  12. Daphnia as a model organism in limnology and aquatic biology: introductory remarks

    Directory of Open Access Journals (Sweden)

    Adam PETRUSEK

    2011-08-01

    Full Text Available Cladocerans of the genus Daphnia are keystone pelagic filter feeders in many temperate ponds and lakes. They have also become popular model organisms in various biological disciplines, from aquatic ecology to biomedical sciences. The crucial features that make these organisms excellent experimental models are their cyclical parthenogenetic life cycle together with easy culturing and handling. Thanks to these characteristics, the number of publications dealing with Daphnia is rapidly growing. The special insert to the Journal of Limnology on Daphnia biology contains contributions that deal directly or indirectly with the reproduction and development of these water fleas, in relation to various ecological factors. These include predator-prey interactions and their impact on morphology, population dynamics, or senescence-related traits, growth of daphnids on a diet consisting of invasively spreading cyanobacteria, and also the impact of extreme floods on a Daphnia population (and particularly on its dormant ephippial egg bank in a reservoir. Here, we discuss these presented works, and point out the potential lines of research that may improve the generalisation of their findings.

  13. Unexpected toxicity to aquatic organisms of some aqueous bisphenol A samples treated by advanced oxidation processes.

    Science.gov (United States)

    Tišler, Tatjana; Erjavec, Boštjan; Kaplan, Renata; Şenilă, Marin; Pintar, Albin

    2015-01-01

    In this study, photocatalytic and catalytic wet-air oxidation (CWAO) processes were used to examine removal efficiency of bisphenol A from aqueous samples over several titanate nanotube-based catalysts. Unexpected toxicity of bisphenol A (BPA) samples treated by means of the CWAO process to some tested species was determined. In addition, the CWAO effluent was recycled five- or 10-fold in order to increase the number of interactions between the liquid phase and catalyst. Consequently, the inductively coupled plasma mass spectrometry (ICP-MS) analysis indicated higher concentrations of some toxic metals like chromium, nickel, molybdenum, silver, and zinc in the recycled samples in comparison to both the single-pass sample and the photocatalytically treated solution. The highest toxicity of five- and 10-fold recycled solutions in the CWAO process was observed in water fleas, which could be correlated to high concentrations of chromium, nickel, and silver detected in tested samples. The obtained results clearly demonstrated that aqueous samples treated by means of advanced oxidation processes should always be analyzed using (i) chemical analyses to assess removal of BPA and total organic carbon from treated aqueous samples, as well as (ii) a battery of aquatic organisms from different taxonomic groups to determine possible toxicity. PMID:26114268

  14. An in vitro screening with emerging contaminants reveals inhibition of carboxylesterase activity in aquatic organisms.

    Science.gov (United States)

    Solé, Montserrat; Sanchez-Hernandez, Juan C

    2015-12-01

    Pharmaceuticals and personal care products (PPCPs) form part of the new generation of pollutants present in many freshwater and marine ecosystems. Although environmental concentrations of these bioactive substances are low, they cause sublethal effects (e.g., enzyme inhibition) in non-target organisms. However, little is known on metabolism of PPCPs by non-mammal species. Herein, an in vitro enzyme trial was performed to explore sensitivity of carboxylesterase (CE) activity of aquatic organisms to fourteen PPCPs. The esterase activity was determined in the liver of Mediterranean freshwater fish (Barbus meridionalis and Squalius laietanus), coastal marine fish (Dicentrarchus labrax and Solea solea), middle-slope fish (Trachyrhynchus scabrus), deep-sea fish (Alepocephalus rostratus and Cataetix laticeps), and in the digestive gland of a decapod crustacean (Aristeus antennatus). Results showed that 100μM of the lipid regulators simvastatin and fenofibrate significantly inhibited (30-80% of controls) the CE activity of all target species. Among the personal care products, nonylphenol and triclosan were strong esterase inhibitors in most species (36-68% of controls). Comparison with literature data suggests that fish CE activity is as sensitive to inhibition by some PPCPs as that of mammals, although their basal activity levels are lower than in mammals. Pending further studies on the interaction between PPCPs and CE activity, we postulate that this enzyme may act as a molecular sink for certain PPCPs in a comparable way than that described for the organophosphorus pesticides.

  15. Exploring how organic matter controls structural transformations in natural aquatic nanocolloidal dispersions.

    Science.gov (United States)

    King, Stephen M; Jarvie, Helen P

    2012-07-01

    The response of the dispersion nanostructure of surface river bed sediment to the controlled removal and readdition of natural organic matter (NOM), in the absence and presence of background electrolyte, was examined using the technique of small-angle neutron scattering (SANS). Partial NOM removal induced aggregation of the mineral particles, but more extensive NOM removal restored colloidal stability. When peat humic acid (PHA) was added to a NOM-deficient sediment concentration-related structural transformations were observed: at 255 mg/L PHA aggregation of the nanocolloid was actually enhanced, but at 380 mg/L PHA disaggregation and colloidal stability were promoted. The addition of 2 mM CaCl(2) induced mild aggregation in the native sediment but not in sediments with added PHA, suggesting that the native NOM and the PHA respond differently to changes in ionic strength. A first attempt at using SANS to directly characterize the thickness and coverage of an adsorbed PHA layer in a natural nanocolloid is also presented. The results are discussed in the context of a hierarchical aquatic colloidal nanostructure, and the implications for contemporary studies of the role of dissolved organic carbon (DOC) in sustaining the transport of colloidal iron in upland catchments.

  16. SOIL NITROGEN TRANSFORMATIONS AND ROLE OF LIGHT FRACTION ORGANIC MATTER IN FOREST SOILS

    Science.gov (United States)

    Depletion of soil organic matter through cultivation may alter substrate availability for microbes, altering the dynamic balance between nitrogen (N) immobilization and mineralization. Soil light fraction (LF) organic matter is an active pool that decreases upon cultivation, and...

  17. Chemical calibration, performance, validation and applications of the polar organic chemical integrative sampler (POCIS) in aquatic environments

    OpenAIRE

    Morin, N.; Miège, C.; Coquery, M.; Randon, J.

    2012-01-01

    POCIS (Polar Organic Chemical Integrative Sampler) is a relatively recent integrative sampler developed to trap hydrophilic organic micropollutants in aquatic environments. Nevertheless, at present, there is no review dealing specifically with this tool. The aim of this paper was to compile information from numerous references based on POCIS in order to discuss on the evaluation of time-weighted average concentrations (calibration methods, sampling rates, performance and reference compounds&#...

  18. The Effects of Dissolved Organic Matter on Pollutant Removal and Formation in Aquatic Environment: From Stormwater to Drinking Water

    OpenAIRE

    Hsu, Meng-Horng

    2012-01-01

    Hydrophobic organic pollutants (HOPs), such as polyaromatic hydrocarbons primarily from automobile exhausts and dissolved organic matter (DOM) are ubiquitous in the aquatic environment. The association between DOM and HOPs as a bound interaction of DOM-HOPs minimizes the bioavailability of free HOPs and their potential health effects. In addition, DOM is also the precursor of disinfection by-products involving the disinfection treatment processes.It is very important to understand the relat...

  19. Occurrence and abundance of carbohydrates and amino compounds in sequentially extracted labile soil organic matter fractions.

    Science.gov (United States)

    This study aimed to investigate the content of carbohydrates and amino compounds in three labile fraction of soil organic matter (SOM). Soil samples were collected from two agricultural fields in southern Italy and the light fraction (LF), the 500–53-µm particulate organic matter (POM) and the mobil...

  20. Thermochemical Pretreatments of Organic Fraction of Municipal Solid Waste from a Mechanical-Biological Treatment Plant

    OpenAIRE

    Carlos José Alvarez-Gallego; Luis Alberto Fdez-Güelfo; María de los Angeles Romero Aguilar; Luis Isidoro Romero García

    2015-01-01

    The organic fraction of municipal solid waste (OFMSW) usually contains high lignocellulosic and fatty fractions. These fractions are well-known to be a hard biodegradable substrate for biological treatments and its presence involves limitations on the performance of anaerobic processes. To avoid this, thermochemical pretreatments have been applied on the OFMSW coming from a full-scale mechanical-biological treatment (MBT) plant, in order to pre-hydrolyze the waste and improve the organic matt...

  1. Organic contaminants in Great Lakes tributaries: Prevalence and potential aquatic toxicity.

    Science.gov (United States)

    Baldwin, Austin K; Corsi, Steven R; De Cicco, Laura A; Lenaker, Peter L; Lutz, Michelle A; Sullivan, Daniel J; Richards, Kevin D

    2016-06-01

    Organic compounds used in agriculture, industry, and households make their way into surface waters through runoff, leaking septic-conveyance systems, regulated and unregulated discharges, and combined sewer overflows, among other sources. Concentrations of these organic waste compounds (OWCs) in some Great Lakes tributaries indicate a high potential for adverse impacts on aquatic organisms. During 2010-13, 709 water samples were collected at 57 tributaries, together representing approximately 41% of the total inflow to the lakes. Samples were collected during runoff and low-flow conditions and analyzed for 69 OWCs, including herbicides, insecticides, polycyclic aromatic hydrocarbons, plasticizers, antioxidants, detergent metabolites, fire retardants, non-prescription human drugs, flavors/fragrances, and dyes. Urban-related land cover characteristics were the most important explanatory variables of concentrations of many OWCs. Compared to samples from nonurban watersheds (15% urban land cover) had nearly four times the number of detected compounds and four times the total sample concentration, on average. Concentration differences between runoff and low-flow conditions were not observed, but seasonal differences were observed in atrazine, metolachlor, DEET, and HHCB concentrations. Water quality benchmarks for individual OWCs were exceeded at 20 sites, and at 7 sites benchmarks were exceeded by a factor of 10 or more. The compounds with the most frequent water quality benchmark exceedances were the PAHs benzo[a]pyrene, pyrene, fluoranthene, and anthracene, the detergent metabolite 4-nonylphenol, and the herbicide atrazine. Computed estradiol equivalency quotients (EEQs) using only nonsteroidal endocrine-active compounds indicated medium to high risk of estrogenic effects (intersex or vitellogenin induction) at 10 sites. EEQs at 3 sites were comparable to values reported in effluent. This multifaceted study is the largest, most comprehensive assessment of the

  2. Organic contaminants in Great Lakes tributaries: Prevalence and potential aquatic toxicity.

    Science.gov (United States)

    Baldwin, Austin K; Corsi, Steven R; De Cicco, Laura A; Lenaker, Peter L; Lutz, Michelle A; Sullivan, Daniel J; Richards, Kevin D

    2016-06-01

    Organic compounds used in agriculture, industry, and households make their way into surface waters through runoff, leaking septic-conveyance systems, regulated and unregulated discharges, and combined sewer overflows, among other sources. Concentrations of these organic waste compounds (OWCs) in some Great Lakes tributaries indicate a high potential for adverse impacts on aquatic organisms. During 2010-13, 709 water samples were collected at 57 tributaries, together representing approximately 41% of the total inflow to the lakes. Samples were collected during runoff and low-flow conditions and analyzed for 69 OWCs, including herbicides, insecticides, polycyclic aromatic hydrocarbons, plasticizers, antioxidants, detergent metabolites, fire retardants, non-prescription human drugs, flavors/fragrances, and dyes. Urban-related land cover characteristics were the most important explanatory variables of concentrations of many OWCs. Compared to samples from nonurban watersheds (15% urban land cover) had nearly four times the number of detected compounds and four times the total sample concentration, on average. Concentration differences between runoff and low-flow conditions were not observed, but seasonal differences were observed in atrazine, metolachlor, DEET, and HHCB concentrations. Water quality benchmarks for individual OWCs were exceeded at 20 sites, and at 7 sites benchmarks were exceeded by a factor of 10 or more. The compounds with the most frequent water quality benchmark exceedances were the PAHs benzo[a]pyrene, pyrene, fluoranthene, and anthracene, the detergent metabolite 4-nonylphenol, and the herbicide atrazine. Computed estradiol equivalency quotients (EEQs) using only nonsteroidal endocrine-active compounds indicated medium to high risk of estrogenic effects (intersex or vitellogenin induction) at 10 sites. EEQs at 3 sites were comparable to values reported in effluent. This multifaceted study is the largest, most comprehensive assessment of the

  3. Organic contaminants in Great Lakes tributaries: Prevalence and potential aquatic toxicity

    Science.gov (United States)

    Baldwin, Austin K.; Corsi, Steven R.; DeCicco, Laura A.; Lenaker, Peter L.; Lutz, Michelle A; Sullivan, Daniel J.; Richards, Kevin D.

    2016-01-01

    Organic compounds used in agriculture, industry, and households make their way into surface waters through runoff, leaking septic-conveyance systems, regulated and unregulated discharges, and combined sewer overflows, among other sources. Concentrations of these organic waste compounds (OWCs) in some Great Lakes tributaries indicate a high potential for adverse impacts on aquatic organisms. During 2010–13, 709 water samples were collected at 57 tributaries, together representing approximately 41% of the total inflow to the lakes. Samples were collected during runoff and low-flow conditions and analyzed for 69 OWCs, including herbicides, insecticides, polycyclic aromatic hydrocarbons, plasticizers, antioxidants, detergent metabolites, fire retardants, non-prescription human drugs, flavors/fragrances, and dyes. Urban-related land cover characteristics were the most important explanatory variables of concentrations of many OWCs. Compared to samples from nonurban watersheds ( 15% urban land cover) had nearly four times the number of detected compounds and four times the total sample concentration, on average. Concentration differences between runoff and low-flow conditions were not observed, but seasonal differences were observed in atrazine, metolachlor, DEET, and HHCB concentrations. Water quality benchmarks for individual OWCs were exceeded at 20 sites, and at 7 sites benchmarks were exceeded by a factor of 10 or more. The compounds with the most frequent water quality benchmark exceedances were the PAHs benzo[a]pyrene, pyrene, fluoranthene, and anthracene, the detergent metabolite 4-nonylphenol, and the herbicide atrazine. Computed estradiol equivalency quotients (EEQs) using only nonsteroidal endocrine-active compounds indicated medium to high risk of estrogenic effects (intersex or vitellogenin induction) at 10 sites. EEQs at 3 sites were comparable to values reported in effluent. This multifaceted study is the largest, most comprehensive assessment of the

  4. The role of storm flows in concentration of pesticides associated with particulate and dissolved fractions as a threat to aquatic ecosystems - Case study: the agricultural watershed of Save river (Southwest of France

    Directory of Open Access Journals (Sweden)

    Taghavi L.

    2011-02-01

    Full Text Available Measurement of the fluxes of pesticides was carried out for a year, ending in March 2009, in the Save catchment, in the vicinity of Toulouse. The hydrograph separation technique was used to evaluate the respective contribution of stormflow and baseflow in transport of 12 pesticide molecules. Transport of over 59% of pesticides and their controlling factors such as total suspended matter (TSM, particulate organic carbon (POC and dissolved organic carbon (DOC occurred during storm periods. Hysteresis patterns could be observed in the concentration-discharge relationships only for some molecules between rising and falling periods of the storm hydrograph. Clockwise hysteresis was noticed for low to moderately soluble pesticide molecules and for particulate fractions, which explains the role of surface runoff in pesticide displacement. In contrast, anticlockwise hysteresis was registered for soluble molecules and dissolved fractions, explaining the role of subsurface flows and soil leaching processes. The important role of TSM, POC and DOC in pesticide transport was clearly established. We also came to the conclusion that the role of stormy periods in pesticide movement and their controlling factors worked as a threat to aquatic ecosystems. And there was a positive relation between riverine TSM, POC, DOC and pesticides according to pesticide properties.

  5. Reduction in toxicity of coking wastewater to aquatic organisms by vertical tubular biological reactor.

    Science.gov (United States)

    Zhou, Siyun; Watanabe, Haruna; Wei, Chang; Wang, Dongzhou; Zhou, Jiti; Tatarazako, Norihisa; Masunaga, Shigeki; Zhang, Ying

    2015-05-01

    We conducted a battery of toxicity tests using photo bacterium, algae, crustacean and fish to evaluate acute toxicity profile of coking wastewater, and to evaluate the performance of a novel wastewater treatment process, vertical tubular biological reactor (VTBR), in the removal of toxicity and certain chemical pollutants. A laboratory scale VTBR system was set up to treat industrial coking wastewater, and investigated both chemicals removal efficiency and acute bio-toxicity to aquatic organisms. The results showed that chemical oxygen demand (COD) and phenol reductions by VTBR were approximately 93% and 100%, respectively. VTBR also reduced the acute toxicity of coking wastewater significantly: Toxicity Unit (TU) decreased from 21.2 to 0.4 for Photobacterium phosphoreum, from 9.5 to 0.6 for Isochrysis galbana, from 31.9 to 1.3 for Daphnia magna, and from 30.0 to nearly 0 for Danio rerio. VTBR is an efficient treatment method for the removal of chemical pollutants and acute bio-toxicity from coking wastewater.

  6. Analysis of aquatic-phase natural organic matter by optimized LDI-MS method.

    Science.gov (United States)

    Wang, Ren-Qi; Druckenmüller, Katharina; Elbers, Gereon; Guenther, Klaus; Croué, Jean-Philippe

    2014-02-01

    The composition and physiochemical properties of aquatic-phase natural organic matter (NOM) are most important problems for both environmental studies and water industry. Laser desorption/ionization (LDI) mass spectrometry facilitated successful examinations of NOM, as humic and fulvic acids in NOM are readily ionized by the nitrogen laser. In this study, hydrophobic NOMs (HPO NOMs) from river, reservoir and waste water were characterized by this technique. The effect of analytical variables like concentration, solvent composition and laser energy was investigated. The exact masses of small molecular NOM moieties in the range of 200-1200 m/z were determined in reflectron mode. In addition, spectra of post-source-decay experiments in this range showed that some compounds from different natural NOMs had the same fragmental ions. In the large mass range of 1200-15,000 Da, macromolecules and their aggregates were found in HPO NOMs from natural waters. Highly humic HPO exhibited mass peaks larger than 8000 Da. On the other hand, the waste water and reservoir water mainly had relatively smaller molecules of about 2000 Da. The LDI-MS measurements indicated that highly humic river waters were able to form large aggregates and membrane foulants, while the HPO NOMs from waste water and reservoir water were unlikely to form large aggregates. PMID:24464543

  7. Environmental DNA sampling protocol - filtering water to capture DNA from aquatic organisms

    Science.gov (United States)

    Laramie, Matthew B.; Pilliod, David S.; Goldberg, Caren S.; Strickler, Katherine M.

    2015-09-29

    Environmental DNA (eDNA) analysis is an effective method of determining the presence of aquatic organisms such as fish, amphibians, and other taxa. This publication is meant to guide researchers and managers in the collection, concentration, and preservation of eDNA samples from lentic and lotic systems. A sampling workflow diagram and three sampling protocols are included as well as a list of suggested supplies. Protocols include filter and pump assembly using: (1) a hand-driven vacuum pump, ideal for sample collection in remote sampling locations where no electricity is available and when equipment weight is a primary concern; (2) a peristaltic pump powered by a rechargeable battery-operated driver/drill, suitable for remote sampling locations when weight consideration is less of a concern; (3) a 120-volt alternating current (AC) powered peristaltic pump suitable for any location where 120-volt AC power is accessible, or for roadside sampling locations. Images and detailed descriptions are provided for each step in the sampling and preservation process.

  8. Analysis of aquatic-phase natural organic matter by optimized LDI-MS method

    KAUST Repository

    Wang, Renqi

    2014-01-26

    The composition and physiochemical properties of aquatic-phase natural organic matter (NOM) are most important problems for both environmental studies and water industry. Laser desorption/ionization (LDI) mass spectrometry facilitated successful examinations of NOM, as humic and fulvic acids in NOM are readily ionized by the nitrogen laser. In this study, hydrophobic NOMs (HPO NOMs) from river, reservoir and waste water were characterized by this technique. The effect of analytical variables like concentration, solvent composition and laser energy was investigated. The exact masses of small molecular NOM moieties in the range of 200-1200 m/z were determined in reflectron mode. In addition, spectra of post-source-decay experiments in this range showed that some compounds from different natural NOMs had the same fragmental ions. In the large mass range of 1200-15 000 Da, macromolecules and their aggregates were found in HPO NOMs from natural waters. Highly humic HPO exhibited mass peaks larger than 8000 Da. On the other hand, the waste water and reservoir water mainly had relatively smaller molecules of about 2000 Da. The LDI-MS measurements indicated that highly humic river waters were able to form large aggregates and membrane foulants, while the HPO NOMs from waste water and reservoir water were unlikely to form large aggregates. Copyright © 2014 John Wiley & Sons, Ltd.

  9. Environmental DNA sampling protocol - filtering water to capture DNA from aquatic organisms

    Science.gov (United States)

    Laramie, Matthew B.; Pilliod, David S.; Goldberg, Caren S.; Strickler, Katherine M.

    2015-01-01

    Environmental DNA (eDNA) analysis is an effective method of determining the presence of aquatic organisms such as fish, amphibians, and other taxa. This publication is meant to guide researchers and managers in the collection, concentration, and preservation of eDNA samples from lentic and lotic systems. A sampling workflow diagram and three sampling protocols are included as well as a list of suggested supplies. Protocols include filter and pump assembly using: (1) a hand-driven vacuum pump, ideal for sample collection in remote sampling locations where no electricity is available and when equipment weight is a primary concern; (2) a peristaltic pump powered by a rechargeable battery-operated driver/drill, suitable for remote sampling locations when weight consideration is less of a concern; (3) a 120-volt alternating current (AC) powered peristaltic pump suitable for any location where 120-volt AC power is accessible, or for roadside sampling locations. Images and detailed descriptions are provided for each step in the sampling and preservation process.

  10. LADTAP-2, Organ Doses to Man and Other Biota from Aquatic Environment

    International Nuclear Information System (INIS)

    LADTAP2 starts with the water concentration at a specific usage location in the environment. The effluent concentration from the impoundment system is related to the water concentrations at the usage locations by two parameters, a dilution factor and a transit time (for radiological decay in transport through the surface water system). The water concentration at the usage location is applied to specific pathway models to estimate the resulting exposure. The pathways included are: ingestion of aquatic foods, such as fish, invertebrates, and aquatic plants; external exposure to shoreline; external exposure to water through boating or swimming; ingestion of drinking water (freshwater sites only); and ingestion of irrigated terrestrial food crops. 3 - Restrictions on the complexity of the problem - Maxima of: 200 nuclides in the release source term, 19 sport fish harvest locations, 19 commercial fish harvest locations, 19 sport invertebrate harvest locations, 19 commercial invertebrate harvest locations, 8 body organs. The radionuclide library contains data for 169 radionuclides

  11. Subcellular localisation of radionuclides by transmission electronic microscopy in aquatic and terrestrial organisms

    International Nuclear Information System (INIS)

    The global framework of this study is to go further in the understanding of the involved mechanisms of uranium and selenium internalisation at the subcellular level and of their toxicity towards several aquatic and terrestrial organisms. In this context, the applications and performances of a Scanning Transmission Electron Microscope (TEM/STEM) equipped with CCD camera and Energy-Dispersive- X-Ray (EDAX) analysis are reported. The principal merit of this equipment is the clear expression of element distribution with nanometer resolution. The sample for TEM analysis were prepared in ultrathin sections of 70-140 nm (thickness) and those for EDAX in sections of 200-500 nm. This method offers the possibility of a direct correlation between histological image and distribution map of trace elements. For each sample, following TEM analysis, EDAX spectra or EDAX mapping were also recorded to confirm the identity of the electron dense material in the scanned sections. Demonstration of the usefulness of this method to understand the bioaccumulation mechanisms and to study the effect of the pollutant uptake at the subcellular level was performed for target organs of a metal (U) and a metalloid (Se) in various biological models: a higher rooted plant (Phaseolus vulgaris)) and a freshwater invertebrate (Orconectes Limosus) and a unicellular green alga (Chlamydomonas reinhardtii)). TEM-EDAX analysis revealed the presence of U-deposits in gills and digestive gland in crayfish, and in vacuoles or in the cytoplasm of different rooted cells bean. In the alga, the accumulation of Se was found in electron-dense granules within cytoplasm associated with ultrastructural changes and starch accumulation. (author)

  12. Fish Karyome version 2.1: a chromosome database of fishes and other aquatic organisms.

    Science.gov (United States)

    Nagpure, Naresh Sahebrao; Pathak, Ajey Kumar; Pati, Rameshwar; Rashid, Iliyas; Sharma, Jyoti; Singh, Shri Prakash; Singh, Mahender; Sarkar, Uttam Kumar; Kushwaha, Basdeo; Kumar, Ravindra; Murali, S

    2016-01-01

    A voluminous information is available on karyological studies of fishes; however, limited efforts were made for compilation and curation of the available karyological data in a digital form. 'Fish Karyome' database was the preliminary attempt to compile and digitize the available karyological information on finfishes belonging to the Indian subcontinent. But the database had limitations since it covered data only on Indian finfishes with limited search options. Perceiving the feedbacks from the users and its utility in fish cytogenetic studies, the Fish Karyome database was upgraded by applying Linux, Apache, MySQL and PHP (pre hypertext processor) (LAMP) technologies. In the present version, the scope of the system was increased by compiling and curating the available chromosomal information over the globe on fishes and other aquatic organisms, such as echinoderms, molluscs and arthropods, especially of aquaculture importance. Thus, Fish Karyome version 2.1 presently covers 866 chromosomal records for 726 species supported with 253 published articles and the information is being updated regularly. The database provides information on chromosome number and morphology, sex chromosomes, chromosome banding, molecular cytogenetic markers, etc. supported by fish and karyotype images through interactive tools. It also enables the users to browse and view chromosomal information based on habitat, family, conservation status and chromosome number. The system also displays chromosome number in model organisms, protocol for chromosome preparation and allied techniques and glossary of cytogenetic terms. A data submission facility has also been provided through data submission panel. The database can serve as a unique and useful resource for cytogenetic characterization, sex determination, chromosomal mapping, cytotaxonomy, karyo-evolution and systematics of fishes. Database URL: http://mail.nbfgr.res.in/Fish_Karyome. PMID:26980518

  13. Ultraviolet irradiation effects incorporation of nitrate and nitrite nitrogen into aquatic natural organic matter

    Science.gov (United States)

    Thorn, Kevin A.; Cox, Larry G.

    2012-01-01

    One of the concerns regarding the safety and efficacy of ultraviolet radiation for treatment of drinking water and wastewater is the fate of nitrate, particularly its photolysis to nitrite. In this study, 15N NMR was used to establish for the first time that UV irradiation effects the incorporation of nitrate and nitrite nitrogen into aquatic natural organic matter (NOM). Irradiation of 15N-labeled nitrate in aqueous solution with an unfiltered medium pressure mercury lamp resulted in the incorporation of nitrogen into Suwannee River NOM (SRNOM) via nitrosation and other reactions over a range of pH from approximately 3.2 to 8.0, both in the presence and absence of bicarbonate, confirming photonitrosation of the NOM. The major forms of the incorporated label include nitrosophenol, oxime/nitro, pyridine, nitrile, and amide nitrogens. Natural organic matter also catalyzed the reduction of nitrate to ammonia on irradiation. The nitrosophenol and oxime/nitro nitrogens were found to be susceptible to photodegradation on further irradiation when nitrate was removed from the system. At pH 7.5, unfiltered irradiation resulted in the incorporation of 15N-labeled nitrite into SRNOM in the form of amide, nitrile, and pyridine nitrogen. In the presence of bicarbonate at pH 7.4, Pyrex filtered (cutoff below 290–300 nm) irradiation also effected incorporation of nitrite into SRNOM as amide nitrogen. We speculate that nitrosation of NOM from the UV irradiation of nitrate also leads to production of nitrogen gas and nitrous oxide, a process that may be termed photo-chemodenitrification. Irradiation of SRNOM alone resulted in transformation or loss of naturally abundant heterocyclic nitrogens.

  14. Bacterial utilization of size-fractionated dissolved organic matter

    Digital Repository Service at National Institute of Oceanography (India)

    Khodse, V.B.; Bhosle, N.B.

    Dissolved organic matter (DOM) is an important source of organic carbon for sustaining the growth of heterotrophic bacteria. The bacterial utilization of high-molecular-weight (HMW; greater than 30 kDa to 0.22 mu m) and low-molecular-weight (LMW...

  15. Copper and Zinc Enrichment in Different Size Fractions of Organic Matter from Polluted Soils

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ming-Kui; KE Zi-Xia

    2004-01-01

    Bioavailability of heavy metals in soil organic matter depends on its components. Characterization of heavy metal distributions in different fractions of soil organic matter is needed for better understanding of the fate of heavy metals. This study investigated the accumulation and partitioning of copper and zinc among different size particulate organic matter (POM) fractions in polluted soils from a former iron ore processing site in western Shaoxing County, Zhejiang Province. Physical fractionations were carried out to separate soil primary particles according to their size and density. Copper and Zn had a heterogeneous distribution among soil particle fractions. Copper and Zn were significantly (p < 0.05) enriched in the POM fractions. > 0.05 mm POM and < 0.05 mm fine soil fractions were mainly responsible for Cu and Zn retention in soils. The POM fraction contained up to 1 322 mg Cu kg-1 and 1 115 mg Zn kg-1 and the fine soil fraction contained up to 422 mg Cu kg-1 and 537 mg Zn kg-1. The total POM fraction was responsible for 15.8%-41.2% and 12.2%-31.7% of the total amount of Cu and Zn, respectively, in the polluted soils. The percentages of Cu and Zn associated with organic matter in < 0.05 mm fine soil fractions for the polluted soils ranged from 14.1% to 24.5%, and 5.4% to 15.8%, respectively. Accumulation of soil organic matter could increase enrichment of Gu (or Zn) in the POM fractions. Also, Cu provided a greater enrichment in the POM fractions than Zn.

  16. Ecological Dose Modeling of Aquatic and Riparian Receptors to Strontium-90 with an Emphasis on Radiosensitive Organs

    Energy Technology Data Exchange (ETDEWEB)

    Poston, Ted M.; Traub, Richard J.; Antonio, Ernest J.

    2011-07-20

    The 100-NR-2 site is the location of elevated releases of strontium-90 to the Columbia River via contaminated groundwater. The resulting dose to aquatic and riparian receptors was evaluated in 2005 (DOE 2009) and compared to U.S. Department of Energy (DOE) dose guidance values. We have conducted additional dose assessments for a broader spectrum of aquatic and riparian organisms using RESRAD Biota and specific exposure scenarios. Because strontium-90 accumulates in bone, we have also modeled the dose to the anterior kidney, a blood-forming and immune system organ that lies close to the spinal column of fish. The resulting dose is primarily attributable to the yttrium-90 progeny of strontium-90 and very little of the dose is associated with the beta emission from strontium-90. All dose modeling results were calculated with an assumption of secular equilibrium between strontium-90 and yttrum-90.

  17. Comparison of metal toxic impacts between aquatic and terrestrial organisms: is the free ion concentration a sufficient descriptor?

    DEFF Research Database (Denmark)

    Owsianiak, Mikolaj; Rosenbaum, Ralph K.; Larsen, Henrik Fred;

    2011-01-01

    Characterization of metal toxic impacts in comparative risk assessment and life cycle impact assessment (LCIA) should take into account metal speciation and interactions with soil/water organic constituents, because these mechanisms control metal bioavailability and may influence their toxic...... hypothesis that the free metal ion is an appropriate “general”descriptor of metal toxicity. Results for 128 laboratory tests on Daphnia magna exposed to copper ions (Cu2+) in water show that variation of several orders of magnitude are observed between the toxicity tests. These variations may be a result of...... organisms. Up to three orders of magnitude difference occur for the extreme case of barley (Hordeum vulgare). Given the scarcity of terrestrial effect data compared to aquatic data, reliable and transparent, mechanistic-based predictions of terrestrial toxic impacts from aquatic effect data would be an...

  18. Characterization of organic matter in aquatic systems under strong urban pressure: Sources, physico-chemical properties and interactions with organic pollutants

    OpenAIRE

    Soares-Derome, Caroline; Bressy, Adèle; Varrault, Gilles

    2013-01-01

    13th WWW YES, Arcueil, France – 3 – 7 June 2013 - Invited conference International audience Many organic pollutants are toxic for the aquatic biota but their fate in urban systems is still little studied, especially regarding Dissolved Organic Matter (DOM) effect on their distribution. Strong interactions with DOM play a key role in the speciation, bioavailability and toxicity of micropollutants. Understanding of the interaction processes, their dependence on local conditions and their ...

  19. Aquatic sediments pollution estimate using the metal fractionation, secondary phase enrichment factor calculation, and used statistical methods.

    Science.gov (United States)

    Sakan, Sanja; Popović, Aleksandar; Anđelković, Ivan; Đorđević, Dragana

    2016-06-01

    The sequential extraction procedure of the European Community Bureau of Reference (BCR) was applied for the fractionation of Cd, Cr, Cu, Ni, Pb, Zn, Fe, Mn, and V in the Serbian river sediments. The aim of this paper was to describe a new approach in detection of anthropogenic elements in sediments, related to the Serbian river courses in order to assess their metal contamination. For sediment pollution evaluation, the risk assessment code (RAC) and the secondary phase enrichment factor (KSPEF) were used. Metal fractionation showed more easily mobilized forms predominant for copper, zinc, cadmium, manganese, and lead, which can be one of the indicators for anthropogenic source input. Chromium, nickel, iron, and vanadium found in the residual fraction indicate these metals may be an indicator for natural sources input. Based on RAC classification, results of sediments show no risk (Cr and V), low risk (Ni, Pb, and Fe), medium risk (Cu), high risk (Cd and Zn), and very high risk (Mn). The mean values of KSPEF were Cd > Cu > Zn > Ni > Mn > Pb > Fe > Cr > V, decreasing scale of no to moderately severe enrichment. The sediments were found to be contaminated by heavy metals to various extents, mostly Cd, Cu, and Zn. Research has shown the importance of KSPEF in quantifying degree of metal enrichment in sediments using results of sequential extraction. With the application of this factor, which is not frequently used in the scientific literature, the results obtained with sequential extraction can be used not only for assessment of mobility but also to quantify the metal pollution. PMID:26385383

  20. Changes in different organic matter fractions during conventional treatment and advanced treatment

    Institute of Scientific and Technical Information of China (English)

    Chao Chen; Xiaojian Zhang; Lingxia Zhu; Wenjie He; Hongda Han

    2011-01-01

    XAD-8 resin isolation of organic matter in water was used to divide organic matter into the hydrophobic and hydrophilic fractions.A pilot plant was used to investigate the change in both fractions during conventional and advanced treatment processes.The treatment of hydrophobic organics (HPO), rather than hydrophilic organicas (HPI), should carry greater emphasis due to HPO's higher trihalomethane formation potential (THMFP) and haloacetic acid formation potential (HAAFP).The removal of hydrophobic matter and its transmission into hydrophilic matter reduced ultimate DBP yield during the disinfection process.The results showed that sand filtration, ozonation, and biological activated carbon (BAC) filtration had distinct influences on the removal of both organic fractions.Additionally, the combination of processes changed the organic fraction proportions present during treatment.The use of ozonation and BAC maximized organic matter removal efficiency, especially for the hydrophobic fraction.In sum, the combination of pre-ozonation,conventional treatment, and O3-BAC removed 48% of dissolved organic carbon (DOC), 60% of HPO, 30% of HPI, 63% of THMFP,and 85% of HAAFP.The use of conventional treatment and O3-BAC without pre-ozonation had a comparable performance, removing 51% of DOC, 56% of HPO, 45% of HPI, 61% of THMFP, and 72% of HAAFP.The effectiveness of this analysis method indicated that resin isolation and fractionation should be standardized as an applicable test to help assess water treatment process efficiency.

  1. Development of fauna, micro flora and aquatic organisms database at the vicinity of Gamma Green House in Malaysian Nuclear Agency

    International Nuclear Information System (INIS)

    The biodiversity database of non-human biota which consisted of flora, fauna, aquatic organisms and micro flora at the vicinity of Gamma Greenhouse (GGH) in Malaysian Nuclear Agency is under development. In 2011, a workshop on biodiversity and sampling of flora and fauna by local experts had been conducted in BAB to expose the necessary knowledge to all those involved in this study. Since then, several field surveys had been successfully being carried out covering terrestrial and aquatic ecosystems in order to observe species distribution pattern and to collect the non-human biota samples. The surveys had been conducted according to standard survey procedures and the samples collected were preserved and identified using appropriate techniques. In this paper, the work on fauna, micro flora and aquatic organisms was presented. The fauna and micro flora specimens were kept in Biodiversity Laboratory in Block 44. Based on those field surveys several species of terrestrial vertebrate and invertebrate organisms were spotted. A diverse group of mushroom was found to be present at the study site. The presence of several aquatic zooplankton for example Cyclops, Nauplius; phytoplankton and bacteria for example Klebsiella sp, Enterobacter sp and others in the pond nearby proved that the pond ecosystem is in good condition. Through this study, the preliminary biodiversity list of fauna at the vicinity of the nuclear facility, GGH had been developed and the work will continue for complete baseline data development. Besides that, many principles and methodologies used in ecological survey had been learnt and applied but the skills involved still need to be polished through workshops, collaboration and consultation from local experts. Thus far, several agencies had been approached to gain collaboration and consultation such as Institut Perikanan Malaysia, UKM, UPM and UMT. (author)

  2. Carbon isotope fractionation of sapropelic organic matter during early diagenesis

    Science.gov (United States)

    Spiker, E. C.; Hatcher, P.G.

    1984-01-01

    Study of an algal, sapropelic sediment from Mangrove Lake, Bermuda shows that the mass balance of carbon and stable carbon isotopes in the major organic constituents is accounted for by a relatively straightforward model of selective preservation during diagenesis. The loss of 13C-enriched carbohydrates is the principal factor controlling the intermolecular mass balance of 13C in the sapropel. Results indicate that labile components are decomposed leaving as a residual concentrate in the sediment an insoluble humic substance that may be an original biochemical component of algae and associated bacteria. An overall decrease of up to about 4??? in the ?? 13C values of the organic matter is observed as a result of early diagenesis. ?? 1984.

  3. Characterization of dissolved organic matter fractions from Lake Hongfeng, Southwestern China Plateau

    Institute of Scientific and Technical Information of China (English)

    WANG Liying; WU Fengchang; ZHANG Runyu; LI Wen; LIAO Haiqing

    2009-01-01

    With XAD-series and ion exchange resins, dissolved organic matter (DOM) from Lake Hongfeng in Southwestern China Plateau was isolated into 6 fractions, i.e., humic acid (HA), fulvic acid (FA), hydrophobic neutrals (HON), hydrophilic acids (HIA), hydrophilic bases (HIB) and hydrophilic neutrals (HIN). Those fractions were characterized by high performance size exclusion chromatography, fluorescence spectroscopy and UV absorbance. Among the 6 fractions, FA was predominant and accounted for 51% of the total DOM. The hydrophobic fractions had larger molecular weight (1688--2355 Da) than hydrophilic fractions (1338--1928 Da). A strong correlation was observed between specific UV absorbance at 280 nm, E2/E3 (absorbance at 250 nm to 365 nm), and the molecular weight for DOM fractions. UV-Vis fulvic-like fluorescence peaks were found in all fractions. Protein-like fluorescence peaks existed in HON may indicate that microbial activity was severely in Lake Hongfeng. There was a significant relationship between fluorescence intensities and specific UV absorbance at 254 nm for those DOM fractions, suggesting their similar luminescence characteristics. The values of fluorescence index (?450/500) indicated that hydrophobic fractions may derive from terrestrial sources, in contrast to the hydrophilic fractions from microbial and terrestrial origins. Those results suggest that there were inter-relationships between molecular weight, fluorescence and absorbance characteristics, and also subtle consistencies between the hydrophilic and hydrophobic properties and sources for the 6 fractions from Lake Hongfeng.

  4. The fate of eroded soil organic carbon along a European transect – controls after deposition in terrestrial and aquatic systems

    DEFF Research Database (Denmark)

    Kirkels, Frédérique; Cammeraat, Erik; Kalbitz, Karsten;

    The potential fate of eroded soil organic carbon (SOC) after deposition is key to understand carbon cycling in eroding landscapes. Globally, large quantities of sediments and SOC are redistributed by soil erosion on agricul-tural land, particularly after heavy precipitation events. Deposition...... the sites. The role of the microbial biomass was specifically assessed in relation to SOC turnover. The results of our study broadly enhanced our knowledge about controls on SOC decomposition/stabilization after its deposition in terrestrial and aquatic environments. We envisage that our quantitative...... relationships will contribute to obtain better estimates of the impact of soil erosion on carbon budgets and reduce uncertainties in the linkage between terrestrial and aquatic carbon cycling....

  5. Toxicological assessment of indium nitrate on aquatic organisms and investigation of the effects on the PLHC-1 fish cell line

    Energy Technology Data Exchange (ETDEWEB)

    Zurita, Jorge L. [National Institute of Toxicology and Forensic Sciences, Av. Dr Fedriani s/n, 41009, Seville (Spain); Jos, Angeles [Area of Toxicology, University of Seville, Prof. Garcia Gonzalez 2, 41012, Seville (Spain); Peso, Ana del; Salguero, Manuel [National Institute of Toxicology and Forensic Sciences, Av. Dr Fedriani s/n, 41009, Seville (Spain); Camean, Ana M. [Area of Toxicology, University of Seville, Prof. Garcia Gonzalez 2, 41012, Seville (Spain); Lopez-Artiguez, Miguel [National Institute of Toxicology and Forensic Sciences, Av. Dr Fedriani s/n, 41009, Seville (Spain); Repetto, Guillermo [National Institute of Toxicology and Forensic Sciences, Av. Dr Fedriani s/n, 41009, Seville (Spain); Area of Toxicology, University of Seville, Prof. Garcia Gonzalez 2, 41012, Seville (Spain)], E-mail: repetto@us.es

    2007-11-15

    Indium nitrate is mainly used as a semiconductor in batteries, for plating and other chemical and medical applications. There is a lack of available information about the adverse effects of indium compounds on aquatic organisms. Therefore, the toxic effects on systems from four trophic levels of the aquatic ecosystem were investigated. Firstly, the bacterium Vibrio fischeri, the alga Chlorella vulgaris and the cladoceran Daphnia magna were used in the toxicological evaluation of indium nitrate. The most sensitive model was V. fischeri, with a NOAEL of 0.02 and an EC{sub 50} of 0.04 mM at 15 min. Although indium nitrate should be classified as harmful to aquatic organisms, it is not expected to represent acute risk to the aquatic biota. Secondly, PLHC-1 fish cell line was employed to investigate the effects and mechanisms of toxicity. Although protein content, neutral red uptake, methylthiazol metabolization, lysosomal function and acetylcholinesterase activity were reduced in cells, stimulations were observed for metallothionein levels and succinate dehydrogenase and glucose-6-phosphate dehydrogenase activities. No changes were observed in ethoxyresorufin-O-deethylase activity. To clarify the main events in PLHC-1 cell death induced by indium nitrate, nine modulators were applied. They were related to oxidative stress ({alpha}-tocopherol succinate, mannitol and sodium benzoate), disruption of calcium homeostasis (BAPTA-AM and EGTA), thiol protection (1,4-dithiotreitol), iron chelation (deferoxiamine) or regulation of glutathione levels (2-oxothiazolidine-4-carboxylic acid and malic acid diethyl ester). The main morphological alterations were hydropic degeneration and loss of cells. At least, in partly, toxicity seems to be mediated by oxidative stress, and particularly by NADPH-dependent lipid peroxidation.

  6. DISTRIBUTION OF ORGANIC CARBON IN DIFFERENT SOIL FRACTIONS IN ECOSYSTEMS OF CENTRAL AMAZONIA

    Directory of Open Access Journals (Sweden)

    Jean Dalmo de Oliveira Marques

    2015-02-01

    Full Text Available Organic matter plays an important role in many soil properties, and for that reason it is necessary to identify management systems which maintain or increase its concentrations. The aim of the present study was to determine the quality and quantity of organic C in different compartments of the soil fraction in different Amazonian ecosystems. The soil organic matter (FSOM was fractionated and soil C stocks were estimated in primary forest (PF, pasture (P, secondary succession (SS and an agroforestry system (AFS. Samples were collected at the depths 0-5, 5-10, 10-20, 20-40, 40-60, 60-80, 80-100, 100-160, and 160-200 cm. Densimetric and particle size analysis methods were used for FSOM, obtaining the following fractions: FLF (free light fraction, IALF (intra-aggregate light fraction, F-sand (sand fraction, F-clay (clay fraction and F-silt (silt fraction. The 0-5 cm layer contains 60 % of soil C, which is associated with the FLF. The F-clay was responsible for 70 % of C retained in the 0-200 cm depth. There was a 12.7 g kg-1 C gain in the FLF from PF to SS, and a 4.4 g kg-1 C gain from PF to AFS, showing that SS and AFS areas recover soil organic C, constituting feasible C-recovery alternatives for degraded and intensively farmed soils in Amazonia. The greatest total stocks of carbon in soil fractions were, in decreasing order: (101.3 Mg ha-1 of C - AFS > (98.4 Mg ha-1 of C - FP > (92.9 Mg ha-1 of C - SS > (64.0 Mg ha-1 of C - P. The forms of land use in the Amazon influence C distribution in soil fractions, resulting in short- or long-term changes.

  7. Aquatic Organisms and Petroleum Hydrocarbon Degrading Bacteria Associated with Their Digestive System

    Directory of Open Access Journals (Sweden)

    Janina Šyvokienė

    2014-01-01

    Full Text Available Laboratory investigation was carried out on the abundance and composition of bacteria in the digestive system of a total of 35 specimens, including bivalve molluscs, i.e. swan mussel Anodonta cygnea (Linnaeus, 1758 from Lake Spėra (Širvintos district and swollen river mussel Unio tumidus (Philipson, 1788 from the Curonian Lagoon near Juodkrantė, zebra mussel (Dreissena polymorpha from the Curonian Lagoon near Juodkrantė and an anostracan – Chirocephalus josephinae (Grube, 1853 from a pond in Ilčiukai village, Utena district, and in the water of related water bodies. Studies on bivalve molluscs (swan mussel and swollen river mussel, zebra mussel and an anostracan – Chirocephalus josephinae, as well as microbiological investigation of water demonstrated that the number of microorganisms in the digestive system of mollusc and anostracan species fluctuated and varied between different species and water bodies. The greatest percentage of HDB among total heterotrophic bacteria was found in the digestive system of swollen river mussels (21.53% and in zebra mussels (19.99% caught in the Curonian Lagoon and in the water of the lagoon (24%. A considerably smaller percentage of HDB was detected in the digestive system of swan mussels from Lake Spėra (17.6% and in the water of the lake (16.66%. The smallest percentage of HDB was found in the digestive system of Chirocephalus josephinae (6.63% and in the water of the Ilčiukai pond (2.72%. According to the values of abundance of petroleum hydrocarbon-degrading bacteria (HDB and total coliform bacteria (TCFB in the digestive system of aquatic organisms we can state that the water ecosystem of Ilčiukai pond was the least contaminated with petroleum, its products and sewage water, and the Curonian Lagoon water ecosystem was the most contaminated. Abundance of petroleum hydrocarbons degrading bacteria could be used as a bioindicator reflecting the level of ecosystem pollution petroleum and its

  8. Aquatic Organisms and Petroleum Hydrocarbon Degrading Bacteria Associated with Their Digestive System

    Directory of Open Access Journals (Sweden)

    Janina Šyvokienė

    2013-12-01

    Full Text Available Laboratory investigation was carried out on the abundance and composition of bacteria in the digestive system of a total of 35 specimens, including bivalve molluscs, i.e. swan mussel Anodonta cygnea (Linnaeus, 1758 from Lake Spėra (Širvintos district and swollen river mussel Unio tumidus (Philipson, 1788 from the Curonian Lagoon near Juodkrantė, zebra mussel (Dreissena polymorpha from the Curonian Lagoon near Juodkrantė and an anostracan – Chirocephalus josephinae (Grube, 1853 from a pond in Ilčiukai village, Utena district, and in the water of related water bodies. Studies on bivalve molluscs (swan mussel and swollen river mussel, zebra mussel and an anostracan – Chirocephalus josephinae, as well as microbiological investigation of water demonstrated that the number of microorganisms in the digestive system of mollusc and anostracan species fluctuated and varied between different species and water bodies. The greatest percentage of HDB among total heterotrophic bacteria was found in the digestive system of swollen river mussels (21.53% and in zebra mussels (19.99% caught in the Curonian Lagoon and in the water of the lagoon (24%. A considerably smaller percentage of HDB was detected in the digestive system of swan mussels from Lake Spėra (17.6% and in the water of the lake (16.66%. The smallest percentage of HDB was found in the digestive system of Chirocephalus josephinae (6.63% and in the water of the Ilčiukai pond (2.72%. According to the values of abundance of petroleum hydrocarbon-degrading bacteria (HDB and total coliform bacteria (TCFB in the digestive system of aquatic organisms we can state that the water ecosystem of Ilčiukai pond was the least contaminated with petroleum, its products and sewage water, and the Curonian Lagoon water ecosystem was the most contaminated. Abundance of petroleum hydrocarbons degrading bacteria could be used as a bioindicator reflecting the level of ecosystem pollution petroleum and its

  9. Field evidence for the potential of waterbirds as dispensers of aquatic organisms

    NARCIS (Netherlands)

    Charalambidou, I.; Santamaria, L.

    2005-01-01

    Field collections during November of green-winged teal (Anas crecca), mallard (Anas platyrhynchos), and coot (Fulica atra) feces in Denmark, England, and France were used to examine the potential of waterbirds to disperse aquatic plant, algae, and invertebrate species across Europe. A total of 216 f

  10. Biochemical methane potential tests of different autoclaved and microwaved lignocellulosic organic fractions of municipal solid waste.

    Science.gov (United States)

    Pecorini, Isabella; Baldi, Francesco; Carnevale, Ennio Antonio; Corti, Andrea

    2016-10-01

    The aim of this research was to enhance the anaerobic biodegradability and methane production of two synthetic Organic Fractions of Municipal Solid Waste with different lignocellulosic contents by assessing microwave and autoclave pre-treatments. Biochemical Methane Potential assays were performed for 21days. Changes in the soluble fractions of the organic matter (measured by soluble chemical oxygen demand, carbohydrates and proteins), the first order hydrolysis constant kh and the cumulated methane production at 21days were used to evaluate the efficiency of microwaving and autoclaving pretreatments on substrates solubilization and anaerobic digestion. Microwave treatment led to a methane production increase of 8.5% for both the tested organic fractions while autoclave treatment had an increase ranging from 1.0% to 4.4%. Results showed an increase of the soluble fraction after pre-treatments for both the synthetic organic fractions. Soluble chemical oxygen demand observed significant increases for pretreated substrates (up to 219.8%). In this regard, the mediocre results of methane's production led to the conclusion that autoclaving and microwaving resulted in the hydrolysis of a significant fraction of non-biodegradable organic substances recalcitrant to anaerobic digestion.

  11. Soil warming affects soil organic matter chemistry of all density fractions of a mountain forest soil

    Science.gov (United States)

    Schnecker, Jörg; Wanek, Wolfgang; Borken, Werner; Schindlbacher, Andreas

    2016-04-01

    Rising temperatures enhance microbial decomposition of soil organic matter (SOM) and increase thereby the soil CO2 efflux. Elevated microbial activity might differently affect distinct SOM pools, depending on their stability and accessibility. Soil fractions derived from density fractionation have been suggested to represent SOM pools with different turnover times and stability against microbial decomposition. We here investigated the chemical and isotopic composition of bulk soil and three different density fractions of forest soils from a long term warming experiment in the Austrian Alps. At the time of sampling the soils in this experiment had been warmed during the snow-free period for 8 consecutive years. During that time no thermal adaptation of the microbial community could be identified and CO2 release from the soil continued to be elevated by the warming treatment. Our results which included organic C content, total N content, δ13C, δ 14C, δ 15N and the chemical composition, identified by pyrolysis-GC/MS, showed no significant differences in bulk soil between warming treatment and control. The differences in the three individual fractions (free particulate organic matter, occluded particulate organic matter and mineral associated organic matter) were mostly small and the direction of warming induced change was variable with fraction and sampling depth. We did however find statistically significant effects of warming in all density fractions from 0-10 cm depth, 10-20 cm depth or both. Our results also including significant changes in the supposedly more stable mineral associated organic matter fraction where δ 13C values decreased at both sampling depths and the relative proportion of N-bearing compounds decreased at a sampling depth of 10-20 cm. All the observed changes can be attributed to an interplay of enhanced microbial decomposition of SOM and increased root litter input. This study suggests that soil warming destabilizes all density fractions of

  12. Morphological evolution and reconstruction of silver nanoparticles in aquatic environments: The roles of natural organic matter and light irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Zou, Xiaoyan; Shi, Junpeng [Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen (China); Zhang, Hongwu, E-mail: hwzhang@iue.ac.cn [Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen (China); Ningbo Research Center for Urban Environment, Chinese Academy of Sciences, Ningbo (China)

    2015-07-15

    Highlights: • In the dark, AgNPs formed chain-like structures through bridging effects with NOM. • NOM decelerated the photoreaction of AgNPs but did not stop the photoconversion. • Under extended irradiation, NOM substituted for citrate as a stabilizer. • In different aquatic systems AgNPs would suffer distinct environmental behavior. - Abstract: With the proliferation of silver nanoparticles (AgNPs), their potential entry into the environment has attracted increasing concern. Although photochemical transformation is an important fate of AgNPs in aquatic environments due to their strong light absorption, little is known about the evolution and transformation mechanisms of AgNPs. This study investigated the morphological evolution and reconstruction of AgNPs during photoconversion in the presence of natural organic matter (NOM). In the dark, the AgNPs formed chain-like structures through bridging effects with NOM at concentrations of 0.1 and 1 mg/L, and the proportion of Ag{sup +} in solution in the presence of 10 mg/L NOM was reduced by roughly half compared with that in the absence of NOM. Under irradiation, NOM participated in the photoreaction of AgNPs and can decelerate the photoreaction of AgNPs via several mechanisms, including light attenuation, the formation of a NOM coating, and competing with Ag for photons. Additionally, NOM can substitute for citrate as a stabilizing agent to compensate for the loss of AgNP stability due to citrate mineralization under extended irradiation, producing stable triangular nanosilver in aquatic environments. This study sheds light on the behavioral differences of AgNPs in different aquatic systems, which create uncertainties and difficulties in assessing the environmental risks of AgNPs.

  13. Ecotoxicological effects of selected engineered nano-materials to aquatic organisms in relation to their physicochemicalcharacteristics

    OpenAIRE

    Wong, Wing-yu.; 黃詠如.

    2011-01-01

    Engineered nanomaterials (NMs), defined as artificially made particles possessing at least one dimension within 1 – 100 nm range, have different physical and biological properties from bulk materials of the same chemistry due to their increased surface areas. Their novel properties have facilitated the prolific growth of commercial NM-incorporating products. NMs may be leached into the aquatic environment during the product life-cycle, but their ecological impacts on marine ecosystems are cu...

  14. Exposures of aquatic organisms to the organophosphorus insecticide, chlorpyrifos resulting from use in the United States.

    Science.gov (United States)

    Williams, W Martin; Giddings, Jeffrey M; Purdy, John; Solomon, Keith R; Giesy, John P

    2014-01-01

    Concentrations of CPY in surface waters are an integral determinant of risk to aquatic organisms. CPY has been measured in surface waters of the U.S. in several environmental monitoring programs and these data were evaluated to characterize concentrations, in relation to major areas of use and changes to the label since 2001, particularly the removal of domestic uses. Frequencies of detection and 95th centile concentrations of CPY decreased more than fivefold between 1992 and 2010. Detections in 1992-2001 ranged from 10.2 to 53%, while 2002-2010 detections ranged from 7 to 11%. The 95th centile concentrations ranged from 0.007 to 0.056 j.lg L -I in 1992-2001 and 0.006-0.008 j.lg L -I in 2002-2010.The greatest frequency of detections occurred in samples from undeveloped and agricultural land-use classes. Samples from urban and mixed land-use classes had the smallest frequency of detections and 95th centile concentrations, consistent with the cessation of most homeowner uses in 2001. The active metabolite of CPY, CPYO, was not detected frequently or in large concentrations. In 10,375 analyses from several sampling programs conducted between 1999 and 2012, only 25 detections (0.24% of samples) of CPYO were reported and estimated concentrations were less than the LOQ.Although the monitoring data on CPY provide relevant insight in quantifying the range of concentrations in surface waters, few monitoring programs have sampled at a frequency sufficient to quantify the time-series pattern of exposure. Therefore,numerical simulations were used to characterize concentrations of CPY in water and sediment for three representative high exposure environments in the U.S. Thefate of CPY in the environment is dependent on a number of dissipation and degradation processes. In terms of surface waters, fate in soils is a major driver of the potential for runoff into surface waters and results from a number of dissipation studies in the laboratory were characterized. Aerobic

  15. Radioactive contamination of aquatic organisms of the Yenisei river in the area affected by the activity of a Russian plutonium complex

    International Nuclear Information System (INIS)

    The Yenisei River, one of the world's largest rivers, is contaminated with artificial radionuclides released by a Russian facility producing weapons-grade plutonium, which has been in operation for many years. The aim of the study conducted between 1997 and 2003 was to investigate accumulation of artificial radionuclides by aquatic organisms of the Yenisei River and to estimate the exposure dose rates to organisms from various sources. The aquatic plants sampled were of three species: Potamogeton lucens, Fontinalis antipyretica, and Ceratophyllum demersum. The gamma-spectrometric and radiochemical analysis of the samples of aquatic plants for artificial radionuclides has revealed more than 20 long-lived and short-lived radionuclides, including plutonium isotopes. The aquatic animal Phylolimnogammarus viridis and diatoms also contain artificial radionuclides. For most aquatic organisms under study, the dose received from the artificial irradiation is an order of magnitude higher than the dose received from natural irradiation. As Fontinalis antipyretica features the highest capacity to accumulate artificial radionuclides, it accumulates the largest artificial exposure does among the study aquatic organisms (up to 39 μGy/day)

  16. Calculation of combustible waste fraction (CWF) estimates used in organics safety issue screening

    Energy Technology Data Exchange (ETDEWEB)

    Heasler, P.G.; Gao, F.; Toth, J.J.

    1998-08-01

    This report describes how in-tank measurements of moisture (H{sub 2}O) and total organic carbon (TOC) are used to calculate combustible waste fractions (CWF) for 138 of the 149 Hanford single shell tanks. The combustible waste fraction of a tank is defined as that proportion of waste that is capable of burning when exposed to an ignition source. These CWF estimates are used to screen tanks for the organics complexant safety issue. Tanks with a suitably low fraction of combustible waste are classified as safe. The calculations in this report determine the combustible waste fractions in tanks under two different moisture conditions: under current moisture conditions, and after complete dry out. The first fraction is called the wet combustible waste fraction (wet CWF) and the second is called the dry combustible waste fraction (dry CWF). These two fractions are used to screen tanks into three categories: if the wet CWF is too high (above 5%), the tank is categorized as unsafe; if the wet CWF is low but the dry CWF is too high (again, above 5%), the tank is categorized as conditionally safe; finally, if both the wet and dry CWF are low, the tank is categorized as safe. Section 2 describes the data that was required for these calculations. Sections 3 and 4 describe the statistical model and resulting fit for dry combustible waste fractions. Sections 5 and 6 present the statistical model used to estimate wet CWF and the resulting fit. Section 7 describes two tests that were performed on the dry combustible waste fraction ANOVA model to validate it. Finally, Section 8 presents concluding remarks. Two Appendices present results on a tank-by-tank basis.

  17. Agar Sediment Test for Assessing the Suitability of Organic Waste Streams for Recovering Nutrients by the Aquatic Worm Lumbriculus variegatus.

    Directory of Open Access Journals (Sweden)

    Bob Laarhoven

    Full Text Available An agar sediment test was developed to evaluate the suitability of organic waste streams from the food industry for recovering nutrients by the aquatic worm Lumbriculus variegatus (Lv. The effects of agar gel, sand, and food quantities in the sediment test on worm growth, reproduction, and water quality were studied. Agar gel addition ameliorated growth conditions by reducing food hydrolysis and altering sediment structure. Best results for combined reproduction and growth were obtained with 0.6% agar-gel (20 ml, 10 g. fine sand, 40 g. coarse sand, and 105 mg fish food (Tetramin. With agar gel, ingestion and growth is more the result of addition of food in its original quality. Final tests with secondary potato starch sludge and wheat bran demonstrated that this test is appropriate for the comparison of solid feedstuffs and suspended organic waste streams. This test method is expected to be suitable for organic waste studies using other sediment dwelling invertebrates.

  18. The Dynamics of Organic Matter in Soil Size and Density Fractions Traced by Stable Carbon Isotopes

    Institute of Scientific and Technical Information of China (English)

    刘启明; 王世杰; 朴河春; 欧阳自远

    2003-01-01

    On the basis of different photosynthetic pathways, there is an obvious difference in δ 13C values between C3 plants and C4 plants. In terms of this characteristic, we analyzed the δ 13C values in different size and density fractions from two profile-soil samples either in farmland and forestlands near the Maolan Karst virgin forest, Southwest China, where there were developed C3 plants previously and now are C4 plants. Results showed that the δ13 C values of different size fractions in forestland soil are δ13 Ccoarse sand <δ 13 Cfine sand <δ 13 Coarse silt <δ 13 Celay <δ 13Cfine silt, and the δ 13C values of different size fractions in farmland soil are δ13Ccoarse sand >13 Cfine sand >δ 13Coarse silt >δ 13 Cclay >δ 13 Cfine silt, indicating that soil organic matter is fresh in coarse sand and oldest in fine silt. The δ 13C values of different density fractions in forestland soil are δ 13Clight <δ 13Cheavy, and the δ 13C values of different density fractions in farmland soil are δ13 Clight >δ 13 Cheavy, indicating that the soil organic matter is fresh in light fractions and old in heavy fractions .

  19. Soil organic carbon fractionation for improving agricultural soil quality diagnosis in different management practices.

    Science.gov (United States)

    Trigalet, Sylvain; Chartin, Caroline; Kruger, Inken; Carnol, Monique; Van Oost, Kristof; van Wesemael, Bas

    2016-04-01

    Preserving ecosystem functions of soil organic matter (SOM) in soils is a key challenge. The need for an efficient diagnosis of SOM state in agricultural soils is a priority in order to facilitate the detection of changes in soil quality as a result of changes in management practices. The nature of SOM is complex and cannot readily be monitored due to the heterogeneity of its components. Assessment of the SOM level dynamics, typically characterized as the bulk soil organic carbon (SOC), can be refined by taking into account carbon pools with different turnover rates and stability. Fractionating bulk SOC in meaningful soil organic fractions helps to better diagnose SOC status. By separating carbon associated with clay and fine silt particles (stable carbon with slow turnover rate) and carbon non-associated with this fraction (labile and intermediate carbon with higher turnover rates), effects of management can be detected more efficiently at different spatial and temporal scales. Until now, most work on SOC fractionation has focused on small spatial scales along management or time gradients. The present case study focuses on SOC fractionation applied in order to refine the interpretation of organic matter turnover and SOC sequestration for regional units in Wallonia with comparable climate, management and, to a certain extent, soil conditions. In each unit, random samples from specific land uses are analyzed in order to assess the Normal Operative Ranges (NOR) of SOC fraction contents for each unit and land use combination. Thus, SOC levels of the different fractions of a specific field in a given unit can be compared to its corresponding NOR. It will help to better diagnose agricultural soil quality in terms of organic carbon compared to a bulk SOC diagnosis.

  20. Sublethal effects of tritium on aquatic systems. Ecological effects of lithium and beryllium on important aquatic organisms and associted communities. Teratogenic effects of low-level magnetic fields

    International Nuclear Information System (INIS)

    Continuing studies of the sublethal effects of tritium on freshwater species emphasize the potential for genetic transmission of suppressed immune competence in offspring of parental rainbow trout (Salmo gairdneri) exposed to tritium (0, 0.04, 0.4, 40.0 rads) during embryogenesis. We plan to determine the relative biological effectiveness of tritium beta irradiation when compared to 60Co gamma irradiation using the relatively radiosensitive immune process of rainbow trout. During FY 1979, we concluded genetic effects studies and prepared a manuscript for open literature publication summarizing FY 1977 and FY 1978 studies on the permanence of suppression of the primary immune response in rainbow trout sublethally irradiated during embryogenesis. We are also studying the potential effects of beryllium and lithium on aquatic systems. Because of mining and refining subsequent to the use of these metals in the construction of fusion reactors, increased levels of each are likely to be encountered in surface waters. Studies included an evaluation of potential toxicity of lithium on embryological life stages of rainbow trout and an assessment of fate and effects in artificial stream habitats. Levels of lithium necessary to cause an observed effect would have to be at least three orders of magnitude above observed background. Studies initiated in FY 1978 include evaluation of effects of low-level magnetic fields on embryologic development of rainbow trout. The objective of these studies to provide data useful in assessing potentially harmful effects of low-level magnetic fields encountered by attendant personnel working in the transport and hot cell areas of fusion reactors. This approach is less costly than using mammalian systems, provides large numbers of experimental organisms for meaningful statistical analysis and permits examination of potential latent effects in a representative vertebrate

  1. Estimation of the hydrophobic fraction of dissolved organic matter in water samples using UV photometry.

    Science.gov (United States)

    Dilling, Jörg; Kaiser, Klaus

    2002-12-01

    In this study, we tested a simple and rapid method for the estimation of carbon in the hydrophobic fraction of dissolved organic matter (DOM) of different origin (spruce, pine, and beech litter) in soil water. The method is based on the fact that the hydrophobic fraction of DOM contains almost entirely the aromatic moieties of DOM. Thus, it showed a clearly distinct light absorption at 260 nm compared to the hydrophilic fraction. This light absorption was directly proportional to the concentration of the hydrophobic fraction. Moreover, it was independent of the concentration of the hydrophilic fraction. We compared the concentrations of hydrophobic DOM estimated by the UV method with those of the conventional fractionation using chromatographic columns of XAD-8 macroporous resin and found an excellent agreement between the two methods for both solutions from laboratory sorption experiments and field samples of forest floor leachates and subsoil porewaters. In addition, the absorption at 260 nm of hydrophobic DOM proved to be independent of pH values ranging from 2.0 to 6.5. Compared to the conventional chromatographic fractionation, the method using the UV absorption at 260 nm is less time consuming, needs a much smaller sample volume, and showed a better reproducibility. However, its use is restricted to water samples of low nitrate (< 25 mg L(-1)) and Fe (< 5 mg L(-1)) concentrations and, probably, with the hydrophobic fraction dominated by aromatic compounds deriving from degradation of lignin.

  2. A simultaneous multiple species acute toxicity test comparing relative sensitivities of six aquatic organisms to HgCl{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    McCrary, J.E.; Heagler, M.G. [McNeese State Univ., Lake Charles, LA (United States). Dept. of Biological and Environmental Science

    1995-12-31

    In the last few years there has been concern in the scientific community about observed declines in some amphibian species. These population declines could be reflecting a global phenomenon due to a general class sensitivity or may be part of a natural cycle. The suggestion of an overall greater sensitivity of amphibians is not supported. Studies show that amphibians, as a class, are neither more or less susceptible than fish to environmental conditions. Mercury has been found to be one of the most toxic of the heavy metals introduced into amphibian breeding waters. Six aquatic species were simultaneously exposed in a comparative acute toxicity test with mercury chloride: three amphibians, Rana catesbeiana (bullfrog), R. clamitans (green frog), and R. sphenocephala (southern leopard frog, formally classified as R. utricularia); two fish, Gambusia affinis (mosquitofish) and Notemigonus crysoleucas (golden shiner); one aquatic aligochaete, Lumbriculus variegatus (aquatic earthworm). The five test concentrations used were 1.4, 3.9, 12.0, 110.0, and 487.0 {micro}g Hg/L respectively. Ten organisms per species were randomly placed into the six test tanks (control and five concentrations), each species in a separate chamber. The resultant LC50-96hr values produced the following rank order: R. sphenocephala, 6.59 {micro}g Hg/L; R. clamitans, 14.7 {micro}g Hg/L; N. crysoleucas, 16.75 {micro}g Hg/L; L. variegatus, 43.72,ug Hg/L; G. affinis, 52.62 {micro}g Hg/L; R. catesbeiana, 63.36 {micro}g Hg/L. No general organism class sensitivity trend, for amphibians, was developed from this data, contrary to the implicit suggestions of some researchers.

  3. Guidance on tiered risk assessment for plant protection products for aquatic organisms in edge-of-field surface waters

    Directory of Open Access Journals (Sweden)

    EFSA Panel on Plant Protection Products and their Residues (PPR

    2013-07-01

    Full Text Available EFSA’s Panel on Plant Protection Products and their Residues (PPR was tasked to revise the Guidance Document (GD on Aquatic Ecotoxicology under Council Directive 91/414/EEC (SANCO/3268/2001 rev.4 (final, 17 October 2002. This Guidance of the PPR Panel is the first of three requested deliverables within this mandate. It has its focus on tiered acute and chronic effect assessment schemes with detailed guidance on tier 1 and higher tier effect assessments for aquatic organisms in edge-of-field surface waters and on proposals regarding how to link effects to exposure estimates. The exposure assessment methodology was not reviewed and it is assumed that the current FOCUS surface water exposure assessment methodology will continue to be used for exposure assessment at EU level. The current GD is intended to be used for authorisation of active substances at EU level as well as for plant protection products at Member State level. The effect assessment schemes in this GD allow for the derivation of regulatory acceptable concentrations (RACs on the basis of two options: (1 the ecological threshold option (ETO, accepting negligible population effects only, and (2 the ecological recovery option (ERO, accepting some population-level effects if ecological recovery takes place within an acceptable time period. In the tiered effect assessment schemes, in principle, all tiers (1, 2 and 3 are able to address the ETO, while the model ecosystem approach (tier 3, under certain conditions, is able to also address the ERO. The GD provides the scientific background for the risk assessment to aquatic organisms in edge-of-field surface waters and is structured to give detailed guidance on all assessment steps. An executive summary joining all parts of the guidance and decision schemes in a concise way is provided and is intended to help applicants and regulatory authorities in day-to-day use.

  4. Anaerobic Digestion of the Organic Fraction of Municipal Solid Waste With Recirculation of Process Water

    DEFF Research Database (Denmark)

    Hartmann, H.; Angelidaki, Irini; Ahring, Birgitte Kiær

    2001-01-01

    A new concept of a wet anaerobic digestion treatment of the organic fraction of municipal solid waste (OFMSW) is investigated. Once the waste is diluted with water, the entire liquid fraction of the effluent is recirculated and used as process water for dilution of the waste. This enables a well......-mixed process without additional water supply. A methane yield of 400 and 445 ml/gVS from OFMSW was achieved in batch and reactor experiments, respectively. Reactor performance with 15 days retention time and an organic loading rate of 4.5 gVS/ld was stable with low VFA concentrations and a VS reduction of 70...

  5. Hydrophilic fraction of natural organic matter causing irreversible fouling of microfiltration and ultrafiltration membranes.

    Science.gov (United States)

    Yamamura, Hiroshi; Okimoto, Kenji; Kimura, Katsuki; Watanabe, Yoshimasa

    2014-05-01

    Although membrane filtration is a promising technology in the field of drinking water treatment, persistent membrane fouling remains a major disadvantage. For more efficient operation, causative agents of membrane fouling need to be identified. Membrane fouling can be classified into physically reversible and irreversible fouling on basis of the removability of the foulants by physical cleaning. Four types of natural organic matter (NOM) in river water used as a source of drinking water were fractionated into hydrophobic and hydrophilic fractions, and their potential to develop irreversible membrane fouling was evaluated by a bench-scale filtration experiment together with spectroscopic and chromatographic analyses. In this study, only dissolved NOM was investigated without consideration of interactions of NOM fractions with particulate matter. Results demonstrated that despite identical total organic carbon (TOC), fouling development trends were significantly different between hydrophilic and hydrophobic fractions. The hydrophobic fractions did not increase membrane resistance, while the hydrophilic fractions caused severe loss of membrane permeability. These results were identical with the case when the calcium was added to hydrophobic and hydrophilic fractions. The largest difference in NOM characteristics between hydrophobic and hydrophilic fractions was the presence or absence of macromolecules; the primary constituent causing irreversible fouling was inferred to be "biopolymers", including carbohydrates and proteins. In addition, the results demonstrated that the extent of irreversible fouling was considerably different depending on the combination of membrane materials and NOM characteristics. Despite identical nominal pore size (0.1 μm), a polyvinylidene fluoride (PVDF) membrane was found to be more rapidly fouled than a PE membrane. This is probably explained by the generation of strong hydrogen bonding between hydroxyl groups of biopolymers and fluorine

  6. Scoping assessment of radiological doses to aquatic organisms and wildlife -- N Springs. [N Springs

    Energy Technology Data Exchange (ETDEWEB)

    Poston, T.M.; Soldat, J.K.

    1992-10-01

    Estimated does rates were determined for endemic biota inhabiting the N Springs area based primarily on spring water data collected from the first 6 months of 1991. Radiological dose estimates were computed from measured values of specific radionuclides and modeled levels of radionuclides using established computer codes. The highest doses were predicted in hypothetical populations of clams, fish-eating ducks, and rabbits. The calculated dose estimates did not exceed 1 rad/d, an administrative dose rate established by the US Department of Energy for the protection of native aquatic biota. An administrative dose rate has not been established for terrestrial wildlife.

  7. Scoping assessment of radiological doses to aquatic organisms and wildlife -- N Springs

    International Nuclear Information System (INIS)

    Estimated does rates were determined for endemic biota inhabiting the N Springs area based primarily on spring water data collected from the first 6 months of 1991. Radiological dose estimates were computed from measured values of specific radionuclides and modeled levels of radionuclides using established computer codes. The highest doses were predicted in hypothetical populations of clams, fish-eating ducks, and rabbits. The calculated dose estimates did not exceed 1 rad/d, an administrative dose rate established by the US Department of Energy for the protection of native aquatic biota. An administrative dose rate has not been established for terrestrial wildlife

  8. Scoping assessment of radiological doses to aquatic organisms and wildlife -- N Springs

    Energy Technology Data Exchange (ETDEWEB)

    Poston, T.M.; Soldat, J.K.

    1992-10-01

    Estimated does rates were determined for endemic biota inhabiting the N Springs area based primarily on spring water data collected from the first 6 months of 1991. Radiological dose estimates were computed from measured values of specific radionuclides and modeled levels of radionuclides using established computer codes. The highest doses were predicted in hypothetical populations of clams, fish-eating ducks, and rabbits. The calculated dose estimates did not exceed 1 rad/d, an administrative dose rate established by the US Department of Energy for the protection of native aquatic biota. An administrative dose rate has not been established for terrestrial wildlife.

  9. [Three-dimensional Fluorescence Spectral Characteristics of Different Molecular Weight Fractionations of Dissolved Organic Matter in the Water-level Fluctuation Zones of Three Gorges Reservoir Areas].

    Science.gov (United States)

    Chen, Xue-shuang; Jiang, Tao; Lu, Song; Wei, Shi-qiang; Wang, Ding-yong; Yan, Jin-long

    2016-03-15

    The study of the molecular weight (MW) fractions of dissolved organic matter (DOM) in aquatic environment is of interests because the size plays an important role in deciding the biogeochemical characteristics of DOM. Thus, using ultrafiltration ( UF) technique combined with three-dimensional fluorescence spectroscopy, DOM samples from four sampling sites in typical water-level fluctuation zones of Three Gorge Reservoir areas were selected to investigate the differences of properties and sources of different DOM MW fractions. The results showed that in these areas, the distribution of MW fractions was highly dispersive, but the approximately equal contributions from colloidal (Mr 1 x 10³-0.22 µm) and true dissolved fraction (Mr low MW (Mr 1 x 10³-10 x 10³) > medium MW (Mr 10 x 10³-30 x 10³) > high MW (Mr 30 x 10³-0.22 µm). Additionally, with decreasing MW fraction, fluorescence index (FI) and freshness index (BIX) increased suggesting enhanced signals of autochthonous inputs, whereas humification index ( HIX) decreased indicating lowe humification degree. It strongly suggested that terrestrial input mainly affected the composition and property of higher MW fractions of DOM, as compared to lower MW and true dissolved fractions that were controlled by autochthonous sources such as microbial and alga activities, instead of allochthonous sources. Meanwhile, the riparian different land-use types also affected obviously on the characteristics of DOM. Therefore, higher diversity of land-use types, and also higher complexity of ecosystem and landscapes, induced higher heterogeneity of fluorescence components in different MW fraction of DOM. PMID:27337878

  10. Parametric Evaluation of Digestability of Organic Fraction of Municipal Solid Waste for Biogas Production

    Directory of Open Access Journals (Sweden)

    Monoj Kumar Mondal

    2015-12-01

    Full Text Available Municipal solid waste was collected from Varanasi’s municipal solid waste dumpsite and sorted for organic fraction present in it. Current work showed the consequences of calcium hydroxide or lime digestion on organic fraction of municipal solid waste of Varanasi, India. The organic fraction of municipal solid waste sample was digested with desired amount of calcium hydroxide. The different concentrations (0.1, 0.2, and 0.5 % of calcium hydroxide was blended separately to substrates (10 % total solid at 30-35 ºC in 3 different beakers denoted by A1, A2 and A3, respectively of 2 L capacity. Experiments of hydrolysis step were conducted on all three samples for evaluation of chemical oxygen demand, pH and volatile fatty acids content in sample. The parameters measured during experiments were chemical oxygen demand, biogas production, total solid, volatile solids, total Kjeldahl nitrogen and total organic carbon. Rate enhancement of anaerobic digestion and biogas production were occurred for calcium hydroxide digested samples. Therefore calcium hydroxide can be used as an effective alkali for the digestion of organic fraction of municipal solid waste.

  11. Improved Cellulose and Organic-Solvents based Lignocellulosic Fractionation Pre-treatment of Organic Waste for Bioethanol Production

    OpenAIRE

    Valeriy Bekmuradov; Grace Luk; Robin Luong

    2014-01-01

    This study investigates the performance of the Cellulose and Organic-Solvents based Lignocellulosic Fractionation (COSLIF) method for the pretreatment of Source-Separated Organic (SSO) waste. An improvement on the standard method of COSLIF pre-treatment was developed based on lower enzyme loading and using an ethanol washing instead of acetone. It was demonstrated that a much higher glucose yield (90% after 72 hours) was possible with this improvement, as compared to the original method, w...

  12. PROCEEDINGS OF A SYMPOSIUM ON COOLING WATER INTAKE TECHNOLOGIES TO PROTECT AQUATIC ORGANISMS

    Science.gov (United States)

    This Symposium brought together professionals from federal, state, and tribal regulatory agencies; industry; environmental organizations; engineering consulting firms; science and research organizations; academia; and other organizations concerned with mitigating harm to the aqua...

  13. Stable carbon and radiocarbon isotope compositions of particle size fractions to determine origins of sedimentary organic matter in an estuary

    NARCIS (Netherlands)

    Megens, L; van der Plicht, J; de Leeuw, JW; Smedes, F; Altabet, M.

    2002-01-01

    Stable and radioactive carbon isotopic compositions of particle size fractions of a surface sediment from the Ems-Dollard estuary vary considerably with particle size. The organic material in the fine fractions (

  14. Organic C and N stabilization in a forest soil: evidence from sequential density fractionation

    Energy Technology Data Exchange (ETDEWEB)

    Sollins, P; Swanston, C; Kleber, M; Filley, T; Kramer, M; Crow, S; Caldwell, B; Lajtha, K; Bowden, R

    2005-07-15

    In mineral soil, organic matter (OM) accumulates mainly on and around surfaces of silt- and clay-size particles. When fractionated according to particle density, C and N concentration (per g fraction) and C/N of these soil organo-mineral particles decrease with increasing particle density across soils of widely divergent texture, mineralogy, location, and management. The variation in particle density is explained potentially by two factors: (1) a decrease in the mass ratio of organic to mineral phase of these particles, and (2) variations in density of the mineral phase. The first explanation implies that the thickness of the organic accumulations decreases with increasing particle density. The decrease in C/N can be explained at least partially by especially stable sorption of cationic peptidic compounds (amine, amide, and pyrrole) directly to mineral surfaces, a phenomenon well documented both empirically and theoretically. These peptidic compounds, along with ligand-exchanged carboxylic compounds, could then form a stable inner organic layer onto which less polar organics could sorb more readily than onto the highly charged mineral surfaces (''onion'' layering model). To explore mechanisms underlying this trend in C concentration and C/N with particle density, we sequentially density fractionated an Oregon andic soil at 1.65, 1.85, 2.00, 2.28, and 2.55 g cm{sup -3} and analyzed the six fractions for measures of organic matter and mineral phase properties. All measures of OM composition showed either: (1) a monotonic change with density, or (2) a monotonic change across the lightest fractions, then little change over the heaviest fractions. Total C, N, and lignin phenol concentration all decreased monotonically with increasing density, and {sup 14}C mean residence time (MRT) increased with particle density from ca. 150 y to >980 y in the four organo-mineral fractions. In contrast, C/N, {sup 13}C and {sup 15}N concentration all showed the

  15. Molecular Characteristics of Kraft-AQ Pulping Lignin Fractionated by Sequential Organic Solvent Extraction

    Directory of Open Access Journals (Sweden)

    Kun Wang

    2010-08-01

    Full Text Available Kraft-AQ pulping lignin was sequentially fractionated by organic solvent extractions and the molecular properties of each fraction were characterized by chemical degradation, GPC, UV, FT-IR, 13C-NMR and thermal analysis. The average molecular weight and polydispersity of each lignin fraction increased with its hydrogen-bonding capacity (Hildebrand solubility parameter. In addition, the ratio of the non-condensed guaiacyl/syringyl units and the content of β-O-4 linkages increased with the increment of the lignin fractions extracted successively with hexane, diethylether, methylene chloride, methanol, and dioxane. Furthermore, the presence of the condensation reaction products was contributed to the higher thermal stability of the larger molecules.

  16. Direct activation of GABAA receptors by substances in the organic acid fraction of Japanese sake.

    Science.gov (United States)

    Izu, Hanae; Shigemori, Kensuke; Eguchi, Masaya; Kawane, Shuhei; Fujii, Shouko; Kitamura, Yuji; Aoshima, Hitoshi; Yamada, Yasue

    2017-01-01

    We investigated the effect of substances present in Japanese sake on the response of ionotropic γ-aminobutyric acid (GABA)A receptors expressed in Xenopus oocytes. Sake was fractionated by ion-exchange chromatography. The fraction containing organic acids (OA fraction) showed agonist activities on the GABAA receptor. OA fractions from sake were analyzed by capillary electrophoresis time-of-flight mass spectrometry (CE-TOFMS). Of the 64 compounds identified, 13 compounds showed GABAA receptor agonist activities. Especially, l-lactic acid showed high agonist activity and its EC50 value was 37μM. Intraperitoneal injections of l-lactic acid, gluconic acid, and pyruvic acid (10, 10, and 5mg/kg BW, respectively), which showed agonistic activity on the GABAA receptor, led to significant anxiolytic effects during an elevated plus-maze test in mice. PMID:27507485

  17. Natural origin arsenic in aquatic organisms from a deep oligotrophic lake under the influence of volcanic eruptions.

    Science.gov (United States)

    Juncos, Romina; Arcagni, Marina; Rizzo, Andrea; Campbell, Linda; Arribére, María; Guevara, Sergio Ribeiro

    2016-02-01

    Volcanic eruptions are recognized sources of toxic elements to freshwater, including arsenic (As). In order to study the short term changes in the bioaccumulation of naturally occurring As by aquatic organisms in Lake Nahuel Huapi (Argentina), located close to the Puyehue-Cordón Caulle volcanic complex (PCCVC), we described As concentrations at different trophic levels and food web transfer patterns in three sites of the lake prior to the last PCCVC eruption (June 2011), and compared As concentrations in biota before and after the eruption. The highest As concentrations and greater variations both between sites and position in the water column, were observed in phytoplankton (3.9-64.8 µg g(-1) dry weight, DW) and small zooplankton (4.3-22.3 µg g(-1) DW). The pattern of As accumulation in aquatic organisms (whole body or muscle) was: primary producers (phytoplankton) > scrapper mollusks (9.3-15.3 µg g(-1) DW) > filter feeding mollusks (5.4-15.6 µg g(-1) DW) > omnivorous invertebrates (0.4-9.2 µg g(-1) DW) > zooplankton (1.2-3.5 µg g(-1) DW) > fish (0.2-1.9 µg g(-1) DW). We observed As biodilution in the whole food web, and in salmonids food chains, feeding on fish prey; but biomagnification in the food chain of creole perch, feeding on benthic crayfish. The impact of the 2011 PCCVC eruption on the As levels of biota was more evident in pelagic-associated organisms (zooplankton and planktivorous fish), but only in the short term, suggesting a brief high bioavailability of As in water after ash deposition. In benthic organisms As variations likely responded to shift in diet due to coverage of the littoral zone with ashes. PMID:26598997

  18. Natural origin arsenic in aquatic organisms from a deep oligotrophic lake under the influence of volcanic eruptions.

    Science.gov (United States)

    Juncos, Romina; Arcagni, Marina; Rizzo, Andrea; Campbell, Linda; Arribére, María; Guevara, Sergio Ribeiro

    2016-02-01

    Volcanic eruptions are recognized sources of toxic elements to freshwater, including arsenic (As). In order to study the short term changes in the bioaccumulation of naturally occurring As by aquatic organisms in Lake Nahuel Huapi (Argentina), located close to the Puyehue-Cordón Caulle volcanic complex (PCCVC), we described As concentrations at different trophic levels and food web transfer patterns in three sites of the lake prior to the last PCCVC eruption (June 2011), and compared As concentrations in biota before and after the eruption. The highest As concentrations and greater variations both between sites and position in the water column, were observed in phytoplankton (3.9-64.8 µg g(-1) dry weight, DW) and small zooplankton (4.3-22.3 µg g(-1) DW). The pattern of As accumulation in aquatic organisms (whole body or muscle) was: primary producers (phytoplankton) > scrapper mollusks (9.3-15.3 µg g(-1) DW) > filter feeding mollusks (5.4-15.6 µg g(-1) DW) > omnivorous invertebrates (0.4-9.2 µg g(-1) DW) > zooplankton (1.2-3.5 µg g(-1) DW) > fish (0.2-1.9 µg g(-1) DW). We observed As biodilution in the whole food web, and in salmonids food chains, feeding on fish prey; but biomagnification in the food chain of creole perch, feeding on benthic crayfish. The impact of the 2011 PCCVC eruption on the As levels of biota was more evident in pelagic-associated organisms (zooplankton and planktivorous fish), but only in the short term, suggesting a brief high bioavailability of As in water after ash deposition. In benthic organisms As variations likely responded to shift in diet due to coverage of the littoral zone with ashes.

  19. Carbon Isotopic Fractionation in Fischer-Tropsch Type Reactions and Relevance to Meteorite Organics

    Science.gov (United States)

    Johnson, Natasha M; Elsila, Jamie E.; Kopstein, Mickey; Nuth, Joseph A., III

    2012-01-01

    Fischer-Tropsch-Type (FTT) reactions have been hypothesized to contribute to the formation of organic compounds in the early solar system, but it has been difficult to identify a signature of such reactions in meteoritic organics. The work reported here examined whether temperature-dependent carbon isotopic fractionation of FTT reactions might provide such a signature. Analyses of bulk organic deposits resulting from FTT experiments show a slight trend towards lighter carbon isotopic ratios with increasing temperature. It is unlikely, however, that these carbon isotopic signatures could provide definitive provenance for organic compounds in solar system materials produced through FTT reactions, because of the small scale of the observed fractionations and the possibility that signatures from many different temperatures may be present in any specific grain.

  20. From a microcosm to the catchment scale: studying the fate of organic runoff pollutants in aquatic ecosystems

    Science.gov (United States)

    Böttcher, T.; Schroll, R.

    2009-04-01

    Spray-drift, drainage, erosion and runoff events are the major causes responsible for deportation of agrochemicals as micropollutants to aquatic non-target sites. These processes can lead to the contamination of nearby freshwater ecosystems with considerably high concentrations of xenobiotics. Thus, it is important to unravel the fate of these pollutants and to evaluate their ecological effects. A novel approach to address this goal was established by the development of a microcosm with multiple sampling abilities enabling quantitative assessment of organic volatilisation, mineralization, metabolization and distribution within the aquatic ecosystem. This microcosm system was designed to support modelling approaches of the catchment scale and gain insights into the fate of pesticides simulating a large scale water body. The potential of this microcosm was exemplified for Isoproturon (IPU), a phenylurea derived systemic herbicide, which is frequently found as contaminant in water samples and with the free-floating macrophyte Lemna minor as non-target species, that is common to occur in rural water bodies. During 21 days exposure time, only a small amount of 14C labeled IPU was removed from the aquatic medium. The major portion (about 5%) was accumulated by Lemna minor resulting in a BCF of 15.8. IPU-volatilisation was very low with 0.13% of the initially applied herbicide. Only a minor amount of IPU was completely metabolized, presumably by rhizosphere microorganisms and released as 14CO2. The novel experimental system allowed to quantitatively investigate the fate of IPU and showed a high reproducibility with a mean average 14C-recovery rate of 97.1

  1. A method for detecting the presence of organic fraction in nucleation mode sized particles

    OpenAIRE

    Vaattovaara, P.; Räsänen, M.; Kühn, T.; Joutsensaari, J.; Laaksonen, a

    2005-01-01

    New particle formation and growth has a very important role in many climate processes. However, the overall knowlegde of the chemical composition of atmospheric nucleation mode (particle diameter, d<20 nm) and the lower end of Aitken mode particles (d≤50 nm) is still insufficient. In this work, we have applied the UFO-TDMA (ultrafine organic tandem differential mobility analyzer) method to shed light on the presence of organic fraction in the nucleation mode size class in differ...

  2. Fractional release factors of long-lived halogenated organic compounds in the tropical stratosphere

    NARCIS (Netherlands)

    Laube, J.C.; Engel, A.; Bönisch, H.; Möbius, T.; Sturges, W.T.; Brass, M.; Rockmann, T.

    2010-01-01

    Fractional release factors (FRFs) of organic trace gases are time-independent quantities that influence the calculation of Global Warming Potentials and Ozone Depletion Potentials. We present the first set of vertically resolved FRFs for 15 long-lived halocarbons in the tropical stratosphere up to 3

  3. Dry anaerobic digestion of the organic fraction of municipal solid waste.

    NARCIS (Netherlands)

    ten Brummeler, E.

    1993-01-01

    Anaerobic digestion is an attractive technology for solid waste management. This thesis describes the technological potentials of dry anaerobic digestion of the organic fraction of Municipal Solid Waste (MSW) using batch systems. In 1985 a research programme was started to develop the so- called BIO

  4. Predicting soil N mineralization: Relevance of organic matter fractions and soil properties.

    NARCIS (Netherlands)

    Ros, G.H.; Hanegraaf, M.C.; Hoffland, E.; Riemsdijk, van W.H.

    2011-01-01

    Distinct extractable organic matter (EOM) fractions have been used to assess the capacity of soils to supply nitrogen (N). However, substantial uncertainty exists on their role in the N cycle and their functional dependency on soil properties. We therefore examined the variation in mineralizable N a

  5. Dissolved organic matter (DOM) dynamics in spruce forested sites -examinations by analytical DOM fractionation

    International Nuclear Information System (INIS)

    Dissolved organic matter from two spruce forested sites in the Fichtelgebirge (Germany) was divided into different chemical and functional fractions, and the budgets of the fractions obtained were calculated. For both sites hydrophobic acids (HoS), hydropholic acids (HiS), hydrophobic neutrals (HoN), hydrophilic neutrals (HiN), and hydrophilic bases (HiB) are discriminated concerning their dynamics in the compartments. Most of the HiN and HoN are mobilized by leaching from the forest canopy. Both neutral fractions are netto retained in the forest floor as well as in the mineral soil. In contrast, HoS and HiS are mainly released in the organic layers with a total input of organic acids from the forest floor into the mineral soil of ca. 100 kg C (HoS) ha-1 a-1, and 50 kg C (HiS) ha-1 a-1, respectively. HoS are selectively better retained in the mineral horizons, leading to a mineral soil output of 2.4-4.4 kg C (HoS) ha-1 a-1, and 2.7-6.5 kg C (HiS) ha-1 a-1, respectively. It is concluded that the different mobility of the DOM fractions has implications for the mobilization and transport or organic pollutants and heavy metals. (orig.)

  6. A method for detecting the presence of organic fraction in nucleation mode sized particles

    Directory of Open Access Journals (Sweden)

    P. Vaattovaara

    2005-06-01

    Full Text Available New particle formation and growth has a very important role in many climate processes. However, the overall knowlegde of the chemical composition of atmospheric nucleation mode (particle diameter, d<20 nm and the lower end of Aitken mode particles (d≤50 nm is still insufficient. In this work, we have applied the UFO-TDMA (ultrafine organic tandem differential mobility analyzer method to shed light on the presence of organic fraction in the nucleation mode size class in different atmospheric environments. The basic principle of the organic fraction detection is based on our laboratory UFO-TDMA measurements with organic and inorganic compounds. Our laboratory measurements indicate that the usefulness of the UFO-TDMA in the field experiments would arise especially from the fact that atmospherically the most relevant inorganic compounds do not grow in subsaturated ethanol vapor, when particle size is 10nm in diameter and saturation ratio is about 86% or below it. Furthermore, internally mixed particles composed of ammonium bisulfate and sulfuric acid with sulfuric acid mass fraction ≤33% show no growth at 85% saturation ratio. In contrast, 10 nm particles composed of various organic compounds of atmospheric relevance are able to grow in those conditions. These discoveries indicate that it is possible to detect the presence of organics in atmospheric nucleation mode sized particles using the UFO-TDMA method. In the future, the UFO-TDMA is expected to be an important aid to describe the composition of atmospheric newly-formed particles.

  7. A method for detecting the presence of organic fraction in nucleation mode sized particles

    Directory of Open Access Journals (Sweden)

    P. Vaattovaara

    2005-01-01

    Full Text Available New particle formation and growth has a very important role in many climate processes. However, the overall knowlegde of the chemical composition of atmospheric nucleation mode (particle diameter, d<20 nm and the lower end of Aitken mode particles (d≤50 nm is still insufficient. In this work, we have applied the UFO-TDMA (ultrafine organic tandem differential mobility analyzer method to shed light on the presence of an organic fraction in the nucleation mode size class in different atmospheric environments. The basic principle of the organic fraction detection is based on our laboratory UFO-TDMA measurements with organic and inorganic compounds. Our laboratory measurements indicate that the usefulness of the UFO-TDMA in the field experiments would arise especially from the fact that atmospherically the most relevant inorganic compounds do not grow in subsaturated ethanol vapor, when particle size is 10 nm in diameter and saturation ratio is about 86% or below it. Furthermore, internally mixed particles composed of ammonium bisulfate and sulfuric acid with sulfuric acid mass fraction ≤33% show no growth at 85% saturation ratio. In contrast, 10 nm particles composed of various oxidized organic compounds of atmospheric relevance are able to grow in those conditions. These discoveries indicate that it is possible to detect the presence of organics in atmospheric nucleation mode sized particles using the UFO-TDMA method. In the future, the UFO-TDMA is expected to be an important aid to describe the composition of atmospheric newly-formed particles.

  8. Distribution of organic carbon in physical fractions of soils as affected by agricultural management

    Energy Technology Data Exchange (ETDEWEB)

    Sindhu, Jagadamma [Oak Ridge National Laboratory (ORNL); Lal, Dr. Rattan [Ohio State University, The, Columbus

    2010-08-01

    Soil organic carbon (SOC) is distributed heterogeneously among different-sized primary particles and aggregates. Further, the SOC associated with different physical fractions respond differently to managements. Therefore, this study was conducted with the objective to quantify the SOC associated with all the three structural levels of SOC (particulate organic matter, soil separates and aggregate-size fractions) as influenced by long-term change in management. The study also aims at reevaluating the concept that the SOC sink capacity of individual size-fractions is limited. Long-term tillage and crop rotation effects on distribution of SOC among fractions were compared with soil from adjacent undisturbed area under native vegetation for the mixed, mesic, Typic Fragiudalf of Wooster, OH. Forty five years of no-till (NT) management resulted in more SOC accumulation in soil surface (0 7.5 cm) than in chisel tillage and plow tillage (PT) treatments. However, PT at this site resulted in a redistribution of SOC from surface to deeper soil layers. The soils under continuous corn accumulated significantly more SOC than those under corn soybean rotation at 7.5 45 cm depth. Although soil texture was dominated by the silt-sized particles, most of the SOC pool was associated with the clay fraction. Compared to PT, the NT treatment resulted in (i) significantly higher proportion of large macroaggregates (>2,000 m) and (ii) 1.5 2.8 times higher SOC concentrations in all aggregate-size classes. A comparative evaluation using radar graphs indicated that among the physical fractions, the SOC associated with sand and silt fractions quickly changed with a land use conversion from native vegetation to agricultural crops. A key finding of this study is the assessment of SOC sink capacity of individual fractions, which revealed that the clay fraction of agricultural soils continues to accumulate more SOC, albeit at a slower rate, with progressive increase in total SOC concentration

  9. Biological effects benchmarks for the protection of aquatic organisms against radiation

    International Nuclear Information System (INIS)

    In Canada, regulations developed under the Nuclear Safety Control Act require that license applicants describe the effects on the environment of the nuclear facility to be licensed. For the purpose of assessing risks to the environment the Canadian Nuclear Safety Commission recommends the use of an ecological risk assessment approach. It is based on toxicity benchmarks from chronic exposure studies of reproduction and survival in sensitive species. The benchmarks or Estimated No Effect Values (ENEVs) for the various taxonomic groups are determined from literature data using an ecotoxicological approach. The ENEVs derived for radiation effects on aquatic biota are: 0.6 mGyxd-1 for fish, 2 mGyxd-1 for amphibians and reptiles, 2.4 mGyxd-1 for algae and macrophytes and 4.6 mGyxd-1 for benthic invertebrates. (author)

  10. Acute Toxicity Assessment of Reactive Red 120 to Certain Aquatic Organisms.

    Science.gov (United States)

    Darsana, R; Chandrasehar, G; Deepa, V; Gowthami, Y; Chitrikha, T; Ayyappan, S; Goparaju, A

    2015-11-01

    Laboratory experiments were conducted to evaluate the acute toxicity of a widely used textile dye namely Reactive Red 120 (RR 120) on certain aquatic species such as Pseudokirchneriella subcapitata (green alga), Lemna gibba (duck weed), Daphnia magna (water flea) and Oncorhynchus mykiss (Rainbow trout). All experiments were performed as per the OECD Guidelines for Testing of Chemicals. The toxicity end points of EC50, LC50, NOEC and LOEC for RR 120 were determined with 95% confidence limits using TOX STAT version 3.5. The EC50 of RR 120 for green alga, duck weed and water flea are >100.00, 64.34, 10.40 mg L(-1), respectively and LC50 for Rainbow trout is 78.84 mg L(-1). Based on the results, the test item RR 120 could be classified as non-toxic to green alga, harmful to duck weed and Rainbow trout, toxic to water flea. PMID:26350898

  11. Role of polarity fractions of effluent organic matter in binding and toxicity of silver and copper.

    Science.gov (United States)

    Yoo, Jisu; Shim, Taeyong; Hur, Jin; Jung, Jinho

    2016-11-01

    This study evaluates the effect of the physicochemical properties of effluent organic matter (EfOM) from industrial and sewage wastewater treatment plants (WWTPs) on the binding and toxicity of Ag and Cu. EfOM was isolated into hydrophobic, transphilic, and hydrophilic fractions depending on its polarity, and was characterized by elemental, specific ultraviolet absorbance, and fluorescence excitation-emission matrix analyses. Our results suggest that the EfOM consists of microbially derived non-humic substances that have lower aromaticity than the Suwannee River natural organic matter (SR-NOM). The Freundlich model was better at explaining the binding of Ag and Cu onto both SR-NOM and EfOM than the Langmuir model. In particular, the hydrophilic fractions of sewage EfOM showed higher binding capacities and affinities for Ag and Cu than the corresponding hydrophobic fractions, resulting in better reduction of the acute toxicity of Ag and Cu towards Daphnia magna. However, in the case of both SR-NOM and industrial EfOM, the hydrophobic fractions were more efficient at reducing metal toxicity. These findings suggest that the EfOM has different physicochemical properties compared with NOM and that the binding and toxicity of heavy metals are largely dependent on the polarity fractions of EfOM. PMID:27318731

  12. Antibacterial, antifungal, phytotoxic, antioxidant and hemagglutination activities of organic fractions of Arisaema tortuosum.

    Science.gov (United States)

    Azam, Sadiq; Saqib, Muhammad Shahab; Zar, Faisal; Ahmad, Bashir; Khan, Ibrar; Zeb, Zermina; Khan, Imran

    2016-05-01

    In the current study, the antimicrobial, phytotoxic, haemagglutination and antioxidant potential of crude methanolic extract (Crd. MeOH Ext.) and four organic fractions of Arisaema tortuosum was investigated. All fractions have been screened for antimicrobial properties against eight bacterial pathogens and six fungal pathogens using agar well diffusion and tube dilution method, respectively. Furthermore, the organic fractions were also screened for its phytotoxicity against Lemna minor. Haemagglutination was performed against all human blood groups while free radical scavenging activity was performed to investigate the antioxidant potential of A. tortuosum. Results obtained for antibacterial activity exhibited various degree of zone of inhibition and significant activity was observed for Pseudomonas aeruginosa (27.16±0.60) followed by Bacillus cereus (18.55±0.69) for Crd. MeOH Ext. and chloroform (CHCl3) fraction, respectively while some strains showed resistant at same concentration. Similarly, non-significant antifungal activity was observed for the plant extracts. However, the highest activity among the strains was observed for Alternaria alternata (22±1.24%) and Aspergillus niger (20±1.00%) for ethyl acetate (EtOAc) fraction and Crd. MeOH Ext., respectively. The plant extracts showed good phytotoxic activity with 77.06% inhibition for n-hexane fraction at 1000µg/mL. The result of Nitric Oxide (NO) reducing assay revealed that the plant has less antioxidant activity with 46.06% inhibition for CHCl(3) fraction at 900μg/mL. For haemagglutination assay, the result displayed no agglutination in all the testing concentration. Based on the current results, it can be concluded that A. tortuosum has significant antimicrobial and moderate phytotoxic potential and therefore can leads to antibiotics and herbicide production. PMID:27166544

  13. Thermochemical pretreatments of organic fraction of municipal solid waste from a mechanical-biological treatment plant.

    Science.gov (United States)

    Álvarez-Gallego, Carlos José; Fdez-Güelfo, Luis Alberto; de los Ángeles Romero Aguilar, María; Romero García, Luis Isidoro

    2015-02-09

    The organic fraction of municipal solid waste (OFMSW) usually contains high lignocellulosic and fatty fractions. These fractions are well-known to be a hard biodegradable substrate for biological treatments and its presence involves limitations on the performance of anaerobic processes. To avoid this, thermochemical pretreatments have been applied on the OFMSW coming from a full-scale mechanical-biological treatment (MBT) plant, in order to pre-hydrolyze the waste and improve the organic matter solubilisation. To study the solubilisation yield, the increments of soluble organic matter have been measured in terms of dissolved organic carbon (DOC), soluble chemical oxygen demand (sCOD), total volatile fatty acids (TVFA) and acidogenic substrate as carbon (ASC). The process variables analyzed were temperature, pressure and NaOH dosage. The levels of work for each variable were three: 160-180-200 °C, 3.5-5.0-6.5 bar and 2-3-4 g NaOH/L. In addition, the pretreatment time was also modified among 15 and 120 min. The best conditions for organic matter solubilisation were 160 °C, 3 g NaOH/L, 6.5 bar and 30 min, with yields in terms of DOC, sCOD, TVFA and ASC of 176%, 123%, 119% and 178% respectively. Thus, predictably the application of this pretreatment in these optimum conditions could improve the H2 production during the subsequent Dark Fermentation process.

  14. Thermochemical pretreatments of organic fraction of municipal solid waste from a mechanical-biological treatment plant.

    Science.gov (United States)

    Álvarez-Gallego, Carlos José; Fdez-Güelfo, Luis Alberto; de los Ángeles Romero Aguilar, María; Romero García, Luis Isidoro

    2015-01-01

    The organic fraction of municipal solid waste (OFMSW) usually contains high lignocellulosic and fatty fractions. These fractions are well-known to be a hard biodegradable substrate for biological treatments and its presence involves limitations on the performance of anaerobic processes. To avoid this, thermochemical pretreatments have been applied on the OFMSW coming from a full-scale mechanical-biological treatment (MBT) plant, in order to pre-hydrolyze the waste and improve the organic matter solubilisation. To study the solubilisation yield, the increments of soluble organic matter have been measured in terms of dissolved organic carbon (DOC), soluble chemical oxygen demand (sCOD), total volatile fatty acids (TVFA) and acidogenic substrate as carbon (ASC). The process variables analyzed were temperature, pressure and NaOH dosage. The levels of work for each variable were three: 160-180-200 °C, 3.5-5.0-6.5 bar and 2-3-4 g NaOH/L. In addition, the pretreatment time was also modified among 15 and 120 min. The best conditions for organic matter solubilisation were 160 °C, 3 g NaOH/L, 6.5 bar and 30 min, with yields in terms of DOC, sCOD, TVFA and ASC of 176%, 123%, 119% and 178% respectively. Thus, predictably the application of this pretreatment in these optimum conditions could improve the H2 production during the subsequent Dark Fermentation process. PMID:25671816

  15. Fractionation and identification of organic matter in natural and fossil-fuel contaminated aquifer systems

    International Nuclear Information System (INIS)

    The separation, fractionation and identification of organic matter in ground water and subsurface solids have most often been done to identify selected, regulated aromatic compounds. In most cases exhaustive and costly analytical determinations result in the identification of less than 5% of the total dissolved or particle-associated organic matter. Work has been in progress to identify specific organic metabolites or transformation products of fuels which provide indications of oxidation-reduction reactions and major transformation pathways. Based on the development of an improved procedure for organic carbon determination in volatile and non-volatile fractions, the authors have determined specific organic compounds in ''leachability'' classes which include regulated compounds and novel metabolites/transformation products. Surprising similarities exist between the hydrocarbon, fatty acid and phenolic compounds from uncontaminated and contaminated glacial aquifer settings. Comparisons of selected compounds in various leachability fractions from aquifer materials and in the corresponding ground water from these sites provide substantial detail useful to those involved in remedial treatment design, operation and performance evaluation

  16. Thermochemical Pretreatments of Organic Fraction of Municipal Solid Waste from a Mechanical-Biological Treatment Plant

    Directory of Open Access Journals (Sweden)

    Carlos José Alvarez-Gallego

    2015-02-01

    Full Text Available The organic fraction of municipal solid waste (OFMSW usually contains high lignocellulosic and fatty fractions. These fractions are well-known to be a hard biodegradable substrate for biological treatments and its presence involves limitations on the performance of anaerobic processes. To avoid this, thermochemical pretreatments have been applied on the OFMSW coming from a full-scale mechanical-biological treatment (MBT plant, in order to pre-hydrolyze the waste and improve the organic matter solubilisation. To study the solubilisation yield, the increments of soluble organic matter have been measured in terms of dissolved organic carbon (DOC, soluble chemical oxygen demand (sCOD, total volatile fatty acids (TVFA and acidogenic substrate as carbon (ASC. The process variables analyzed were temperature, pressure and NaOH dosage. The levels of work for each variable were three: 160–180–200 °C, 3.5–5.0–6.5 bar and 2–3–4 g NaOH/L. In addition, the pretreatment time was also modified among 15 and 120 min. The best conditions for organic matter solubilisation were 160 °C, 3 g NaOH/L, 6.5 bar and 30 min, with yields in terms of DOC, sCOD, TVFA and ASC of 176%, 123%, 119% and 178% respectively. Thus, predictably the application of this pretreatment in these optimum conditions could improve the H2 production during the subsequent Dark Fermentation process.

  17. Estimation of the Risks of Collision or Strike to Freshwater Aquatic Organisms Resulting from Operation of Instream Hydrokinetic Turbines

    Energy Technology Data Exchange (ETDEWEB)

    Schweizer, Peter E [ORNL; Cada, Glenn F [ORNL; Bevelhimer, Mark S [ORNL

    2010-05-01

    Hydrokinetic energy technologies have been proposed as renewable, environmentally preferable alternatives to fossil fuels for generation of electricity. Hydrokinetic technologies harness the energy of water in motion, either from waves, tides or from river currents. For energy capture from free-flowing rivers, arrays of rotating devices are most commonly proposed. The placement of hydrokinetic devices in large rivers is expected to increase the underwater structural complexity of river landscapes. Moore and Gregory (1988) found that structural complexity increased local fish populations because fish and other aquatic biota are attracted to structural complexity that provides microhabitats with steep flow velocity gradients (Liao 2007). However, hydrokinetic devices have mechanical parts, blades, wings or bars that move through the water column, posing a potential strike or collision risk to fish and other aquatic biota. Furthermore, in a setting with arrays of hydrokinetic turbines the cumulative effects of multiple encounters may increase the risk of strike. Submerged structures associated with a hydrokinetic (HK) project present a collision risk to aquatic organisms and diving birds (Cada et al. 2007). Collision is physical contact between a device or its pressure field and an organism that may result in an injury to that organism (Wilson et al. 2007). Collisions can occur between animals and fixed submerged structures, mooring equipment, horizontal or vertical axis turbine rotors, and structures that, by their individual design or in combination, may form traps. This report defines strike as a special case of collision where a moving part, such as a rotor blade of a HK turbine intercepts the path of an organism of interest, resulting in physical contact with the organism. The severity of a strike incidence may range from minor physical contact with no adverse effects to the organism to severe strike resulting in injury or death of the organism. Harmful effects

  18. Anaerobic digestion of the shredded organic fraction of municipal solid waste

    Energy Technology Data Exchange (ETDEWEB)

    Traverso, P.G.; Cecchi, Franco

    1988-01-01

    Anaerobic digestion of the shredded organic fraction of municipal solid waste has been investigated in a pilot-scale completely mixed digester, under mesophilic conditions. Detailed comparisons of the size distributions of the particles in the feed and in the digester effluent are reported under varying organic loading rates and hydraulic retention times. About 20% of the particulate matter in the organic feed is refractory and resists hydrolysis. Hence the maximum removal of total volatile solids attainable under hydraulic retention times of practical interest is about 70%. The optimum hydraulic retention time is around 14 to 15 days.

  19. Proteomics to assess the role of phenotypic plasticity in aquatic organisms exposed to pollution and global warming.

    Science.gov (United States)

    Silvestre, Frédéric; Gillardin, Virginie; Dorts, Jennifer

    2012-11-01

    Nowadays, the unprecedented rates of anthropogenic changes in ecosystems suggest that organisms have to migrate to new distributional ranges or to adapt commensurately quickly to new conditions to avoid becoming extinct. Pollution and global warming are two of the most important threats aquatic organisms will have to face in the near future. If genetic changes in a population in response to natural selection are extensively studied, the role of acclimation through phenotypic plasticity (the property of a given genotype to produce different phenotypes in response to particular environmental conditions) in a species to deal with new environmental conditions remains largely unknown. Proteomics is the extensive study of the protein complement of a genome. It is dynamic and depends on the specific tissue, developmental stage, and environmental conditions. As the final product of gene expression, it is subjected to several regulatory steps from gene transcription to the functional protein. Consequently, there is a discrepancy between the abundance of mRNA and the abundance of the corresponding protein. Moreover, proteomics is closer to physiology and gives a more functional knowledge of the regulation of gene expression than does transcriptomics. The study of protein-expression profiles, however, gives a better portrayal of the cellular phenotype and is considered as a key link between the genotype and the organismal phenotype. Under new environmental conditions, we can observe a shift of the protein-expression pattern defining a new cellular phenotype that can possibly improve the fitness of the organism. It is now necessary to define a proteomic norm of reaction for organisms acclimating to environmental stressors. Its link to fitness will give new insights into how organisms can evolve in a changing environment. The proteomic literature bearing on chronic exposure to pollutants and on acclimation to heat stress in aquatic organisms, as well as potential application of

  20. Evaluation of the toxicity of superfine materials to change the physiological functions of aquatic organisms of different trophic levels

    Science.gov (United States)

    Morgalev, S.; Morgaleva, T.; Gosteva, I.; Morgalev, Yu

    2015-11-01

    We assessed ecological and biological effects caused by the physical and chemical properties of nanomaterials on the basis of the laboratory researches into water test-organisms of different trophic levels. We studied the physiological functions of water organisms on adding into the environment superfine materials of various chemical nature and structural characteristics: metallic nanoparticles of nikel (nNi), argentum (nAg), platinum (nPt), aurum (nAu), binary NPs (powder of titanium dioxide - nTiO2, aluminum oxide - nAl2O3, zink oxide - nZnO, silicon nitride - nSi3N4, silicon carbide (nSiC) and carbon nanotubes (BT-50, MCD- material). We observed the dependence of developing the complex of unfavourable biological effects in water plants and entomostracans’ organisms on the physical and chemical properties of superfine materials. We determined the values of NOEC, L(E)C20 and L(E)C50 for aquatic organisms of various regular groups. We found out the most vulnerable elements of the communities’ trophic structure and the possibility of a breakdown in the water ecosystem food pyramid.

  1. Specific absorbed fraction of X-ray in tissues from human organs

    International Nuclear Information System (INIS)

    Full text: X- rays are widely used in medical imaging and radiation therapy. The user of radioisotopes must have knowledge about how radiation interacts with matter, especially with the human body, because when photons enter the medium/body, they degrade their energy and build up in the medium, giving rise to secondary radiation. Calculations of the energy absorbed in a medium include not only the contribution of the uncollided photons from the source, but must also include the contributions from collided and secondary photons. In practice, this is done by multiplying the contribution of the uncollided photons by the energy absorption buildup factor. An accurate absorbed dose calculation needs specific absorbed fraction of energy. Geometric progression (GP) fitting method has been used to compute energy absorption build-up factor of Human organs such as brain, breast, eye lens, GI track, heart, kidney, liver, lung, lymph, ovary, pancreas, testis and skeleton-femur. The computed absorption build-up factor is used to estimate specific absorbed fraction of energy. The thickness of the medium up to 10mm and with penetration depth up to 40 mean free paths considered. The dependence of specific absorbed fraction of energy on incident photon energy, penetration and the thickness of the medium have also been studied. The specific absorbed fraction of energy increases up to the Epe and then decreases. Here Epe is the energy value at which the photo electric interaction coefficients matches with Compton interaction coefficients for a given value of effective atomic number (Zeff). The variation of specific absorbed fractions with energy is due to dominance of photoelectric absorption in the lower end and dominance of pair production in the higher photon energy region. In the lower energy end photoelectric absorption is dominant photon interaction process; hence specific absorbed fractions values minimum. As the energy of incident photon increases, Compton scattering overtakes

  2. Wind speed dependent size-resolved parameterization for the organic mass fraction of sea spray aerosol

    Directory of Open Access Journals (Sweden)

    B. Gantt

    2011-08-01

    Full Text Available For oceans to be a significant source of primary organic aerosol (POA, sea spray aerosol (SSA must be highly enriched with organics relative to the bulk seawater. We propose that organic enrichment at the air-sea interface, chemical composition of seawater, and the aerosol size are three main parameters controlling the organic mass fraction of sea spray aerosol (OMSSA. To test this hypothesis, we developed a new marine POA emission function based on a conceptual relationship between the organic enrichment at the air-sea interface and surface wind speed. The resulting parameterization is explored using aerosol chemical composition and surface wind speed from Atlantic and Pacific coastal stations, and satellite-derived ocean concentrations of chlorophyll-a, dissolved organic carbon, and particulate organic carbon. Of all the parameters examined, a multi-variable logistic regression revealed that the combination of 10 m wind speed and surface chlorophyll-a concentration ([Chl-a] are the most consistent predictors of OMSSA. This relationship, combined with the published aerosol size dependence of OMSSA, resulted in a new parameterization for the organic mass fraction of SSA. Global emissions of marine POA are investigated here by applying this newly-developed relationship to existing sea spray emission functions, satellite-derived [Chl-a], and modeled 10 m winds. Analysis of model simulations shows that global annual submicron marine organic emission associated with sea spray is estimated to be from 2.8 to 5.6 Tg C yr−1. This study provides additional evidence that marine primary organic aerosols are a globally significant source of organics in the atmosphere.

  3. Pesticide Toxicity Index: a tool for assessing potential toxicity of pesticide mixtures to freshwater aquatic organisms

    Science.gov (United States)

    Nowell, Lisa H.; Norman, Julia E.; Moran, Patrick W.; Martin, Jeffrey D.; Stone, Wesley W.

    2014-01-01

    Pesticide mixtures are common in streams with agricultural or urban influence in the watershed. The Pesticide Toxicity Index (PTI) is a screening tool to assess potential aquatic toxicity of complex pesticide mixtures by combining measures of pesticide exposure and acute toxicity in an additive toxic-unit model. The PTI is determined separately for fish, cladocerans, and benthic invertebrates. This study expands the number of pesticides and degradates included in previous editions of the PTI from 124 to 492 pesticides and degradates, and includes two types of PTI for use in different applications, depending on study objectives. The Median-PTI was calculated from median toxicity values for individual pesticides, so is robust to outliers and is appropriate for comparing relative potential toxicity among samples, sites, or pesticides. The Sensitive-PTI uses the 5th percentile of available toxicity values, so is a more sensitive screening-level indicator of potential toxicity. PTI predictions of toxicity in environmental samples were tested using data aggregated from published field studies that measured pesticide concentrations and toxicity to Ceriodaphnia dubia in ambient stream water. C. dubia survival was reduced to ≤ 50% of controls in 44% of samples with Median-PTI values of 0.1–1, and to 0% in 96% of samples with Median-PTI values > 1. The PTI is a relative, but quantitative, indicator of potential toxicity that can be used to evaluate relationships between pesticide exposure and biological condition.

  4. Evidence for the aquatic binding of arsenate by natural organic matter-suspended Fe(III)

    Science.gov (United States)

    Ritter, K.; Aiken, G.R.; Ranville, J.F.; Bauer, M. E.; Macalady, D.L.

    2006-01-01

    Dialysis experiments with arsenate and three different NOM samples amended with Fe(III) showed evidence confirming the formation of aquatic arsenate-Fe(III)-NOM associations. A linear relationship was observed between the amount of complexed arsenate and the Fe(III) content of the NOM. The dialysis results were consistent with complex formation through ferric iron cations acting as bridges between the negatively charged arsenate and NOM functional groups and/or a more colloidal association, in which the arsenate is bound by suspended Fe(III)-NOM colloids. Sequential filtration experiments confirmed that a significant proportion of the iron present at all Fe/C ratios used in the dialysis experiments was colloidal in nature. These colloids may include larger NOM species that are coagulated by the presence of chelated Fe(III) and/or NOM-stabilized ferric (oxy)hydroxide colloids, and thus, the solution-phase arsenate-Fe(III)-NOM associations are at least partially colloidal in nature. ?? 2006 American Chemical Society.

  5. Relationship between light and heavy fractions of organic matter for several agricultural soils in China

    Institute of Scientific and Technical Information of China (English)

    YIN Yun-feng; CAI Zu-cong; LU Jia-long

    2005-01-01

    Although numerous studies about the nature and turnover of soil organic matter(SOM) in light and heavy fractions( LFOM and HFOM, respectively) have been made, little information is available in relation to the relationship between LFOM and HFOM, and no attempts have been made to quantify a general relationship between LFOM and HFOM for agricultural soils under field condition. Our hypothesis is there may be an inherent relationship between LFOM and HFOM for agricultural soils under certain unaltered management practices for a long period, to this end, we therefore studied typically soils taken from different parts in China by using a simple density fractionation procedure. The results indicated that LFOM was positively correlated with LFOM/HFOM ratio for three typical soils. This information will be of particular use not only in deepening our understanding of the dynamics of SOM fractions but also in evaluating the potential of agricultural soils to sequestrate C under different management practices in a long term.

  6. Factors regulating nitrification in aquatic sediments: Effects of organic carbon, nitrogen availability, and pH

    Science.gov (United States)

    Strauss, E.A.; Mitchell, N.L.; Lamberti, G.A.

    2002-01-01

    We investigated the response in nitrification to organic carbon (C) availability, the interactive effects of the C: nitrogen (N) ratio and organic N availability, and differing pH in sediments from several streams in the upper midwestern United States. In addition, we surveyed 36 streams to assess variability in sediment nitrification rates. Labile dissolved organic carbon (DOC) additions of 30 mg C??L-1 (as acetate) to stream sediments reduced nitrification rates (P nitrification. C:N and organic N availability strongly interacted to affect nitrification (P nitrification most at lower C:N. Nitrification was also strongly influenced by pH (P nitrification. Our results suggest that nitrification is regulated by several variables, with NH4+ availability and pH being the most important. Organic C is likely important at regulating nitrification only under high environmental C:N conditions and if most available C is relatively labile.

  7. Concentration of 134Cs + 137Cs bonded to the organic fraction of sediments offshore Fukushima, Japan

    International Nuclear Information System (INIS)

    We conducted a sequential chemical extraction experiment for radiocesium (134Cs + 137Cs) using 21 surface sediment samples and two sets of size-fractionated surface sediment samples collected offshore Fukushima. Our results support earlier reports in this area that organic substances in marine sediments have an apparently higher preference for radiocesium than mineral substances. Observations suggest that mineral and organic substances in the marine sediments offshore Fukushima have the same order of preference for radiocesium, primarily because of the existence of ionic competitors in seawater. The apparent preference of radiocesium for organic material is greater because of the partial coverage of sediment mineral surfaces by organic substances. By using these relationships, we created a 2-D map of radiocesium concentration in sediment organic fraction in offshore-Fukushima region. Combining our results with existing monitoring data of marine benthos in offshore-Fukushima sediments, we estimated a transfer coefficient of radiocesium from sediment organic materials to benthic polychaetes as less than 0.03-0.008. (author)

  8. Comparison of different soil organic matter fractionation methodologies: Evidences from ultrasensitive {sup 14}C measurements

    Energy Technology Data Exchange (ETDEWEB)

    Marzaioli, Fabio, E-mail: fabio.marzaioli@unina2.i [CIRCE, Dipartimento di Scienze Ambientali, Seconda Universita degli studi di Napoli and INNOVA, Via Vivaldi, 43, Caserta 81100 (Italy); Lubritto, Carmine; Galdo, Ilaria Del; D' Onofrio, Antonio [CIRCE, Dipartimento di Scienze Ambientali, Seconda Universita degli studi di Napoli and INNOVA, Via Vivaldi, 43, Caserta 81100 (Italy); Cotrufo, M. Francesca [CIRCE, Dipartimento di Scienze Ambientali, Seconda Universita degli studi di Napoli and INNOVA, Via Vivaldi, 43, Caserta 81100 (Italy); Department of Soil and Crop Sciences, Colorado State University, Fort Collins, Colorado (United States); Terrasi, Filippo [CIRCE, Dipartimento di Scienze Ambientali, Seconda Universita degli studi di Napoli and INNOVA, Via Vivaldi, 43, Caserta 81100 (Italy)

    2010-04-15

    Soils are studied with the aim to predict future climatic scenarios and find the best guidelines to manage terrestrial ecosystems for the mitigation of the atmospheric CO{sub 2} rising. Carbon constituting soil organic matter (SOM) behaves as a cohort of different pools, characterized by a specific C turnover time. Both natural and anthropogenic occurring {sup 14}C reach the soil through plant littering, becoming a valid tool to trace SOM dynamics. In this study we present a series of Accelerator Mass Spectrometry (AMS) {sup 14}C measurements on SOM samples obtained by means of different laboratory protocols used for the isolation of soil pools from bulk soil (fractionation protocols). Radiocarbon signature of SOM fractions is used as a keyhole to look at the more effective fractionation procedure and comparison among measured {sup 14}C on SOM fractions revealed important indications for the proposal of a novel fractionation protocol. Our data put in evidence how particle size controls the recalcitrance of ancient SOM carbon pools.

  9. SOIL ORGANIC MATTER FRACTIONS IN PRESERVED AND DISTURBED WETLANDS OF THE CERRADO BIOME

    Directory of Open Access Journals (Sweden)

    Ricardo Fernandes de Sousa

    2015-02-01

    Full Text Available Veredas are humid tropical ecosystems, generally associated to hydromorphic soils and a shallow water table. The soils of these ecosystems are affected by the use of the areas around these veredas. The objective of this study was to determine soil organic matter (SOM fractions in veredas adjacent to preserved (native savanna and disturbed environments (agricultural areas and pastures in the Cerrado biome. Soil samples were collected from the 0-10 and 10-20 cm layers along reference lines drawn along the relief following the upper, middle and lower positions of one of the slopes, in the direction of the draining line of the vereda. The soil analysis determined: total soil OC, total nitrogen and C:N ratio; C and N contents and C:N ratio in particulate and mineral-associated fractions (of SOM; fulvic acids, humic acids and humin fractions and ratio between humic and fulvic acids. The agricultural use around the veredas induced changes in the SOM fractions, more pronounced in the lower part of the slope. In the soil surface of this part, the OC levels in the humic substances and the particulate fraction of SOM, as well as total soil OC were reduced in the vereda next to crop fields.

  10. The effect of composting on the organic colloidal fraction from domestic sewage sludge

    Science.gov (United States)

    Almendros, Gonzalo; Leal, Juan A.; Martin, Francisco; Gonzalez-Vila, Francisco J.

    Due to the frequent use of domestic sewage sludges as organic additives to soils with low humus content, the chemical characteristics of the extractable polymers from composted and uncomposted sludges were described. The alkali-soluble, acid-insoluble sludge fraction (humic-like) was isolated after exhaustive lipid extraction, and analyzed by chemical degradation followed by combined gas chromatography mass spectrometry. It was observed that this sludge fraction contained an important amount of lipid compounds (more than 40% by weight). Most of this lipid material can be physically removed, but the residual polymer fractions were also found to be highly aliphatic in nature. The high yields upon degradation of several types of alkanoic acids and the relatively high proportion of polypeptides (30% by weight), as well as carbohydrates, suggested that the humic-like fractions from both the composted and uncomposted sludges consisted of slightly altered microbial and residual biopolymers. The effects of composting sludge mainly concern the selective biodegradation of the less resistant moieties. The great differences between the chemical nature of the humic-like fraction of the composted sludge and that of the soil humic acids are considered to reflect the low proportion of lignified materials in the original sludge.

  11. Partitioning of organic carbon among density fractions in surface sediments of Fiordland, New Zealand

    Science.gov (United States)

    Cui, Xingqian; Bianchi, Thomas S.; Hutchings, Jack A.; Savage, Candida; Curtis, Jason H.

    2016-03-01

    Transport of particles plays a major role in redistributing organic carbon (OC) along coastal regions. In particular, the global importance of fjords as sites of carbon burial has recently been shown to be even more important than previously thought. In this study, we used six surface sediments from Fiordland, New Zealand, to investigate the transport of particles and OC based on density fractionation. Bulk, biomarker, and principle component analysis were applied to density fractions with ranges of 2.5 g cm-3. Our results found various patterns of OC partitioning at different locations along fjords, likely due to selective transport of higher density but smaller size particles along fjord head-to-mouth transects. We also found preferential leaching of certain biomarkers (e.g., lignin) over others (e.g., fatty acids) during the density fractionation procedure, which altered lignin-based degradation indices. Finally, our results indicated various patterns of OC partitioning on density fractions among different coastal systems. We further propose that a combination of particle size-density fractionation is needed to better understand transport and distribution of particles and OC.

  12. Strategies for the anaerobic digestion of the organic fraction of municipal solid waste: an overview

    DEFF Research Database (Denmark)

    Hartmann, H.; Ahring, Birgitte Kiær

    2006-01-01

    Different process strategies for anaerobic digestion of the organic fraction of municipal solid waste (OFMSW) are reviewed weighing high-solids versus low-solids, mesophilic versus thermophilic and single-stage versus multi-stage processes. The influence of different waste characteristics...... such as composition of biodegradable fractions, C:N ratio and particle size is described. Generally, source sorting of OFMSW and a high content of food waste leads to higher biogas yields than the use of mechanically sorted OFMSW. Thermophilic processes are more efficient than mesophilic processes in terms of higher...... biogas yields at different organic loading rates (OLR). Highest biogas yields are achieved by means of wet thermophilic processes at OLRs lower than 6 kg-VS(.)m(-3) d(-1). High-solids processes appear to be relatively more efficient when OLRs higher than 6 kg-VS(.)m(-3) d(-1) are applied. Multi...

  13. Particle-size fractionation and stable carbon isotope distribution applied to the study of soil organic matter dynamics

    International Nuclear Information System (INIS)

    The present Note concerns the dynamics of organic matter in soils under forest (C3-type vegetation) and 12 and 50 years old sugar-cane (C4-type vegetation) cultivation. The decomposition rate of ‘forest organic matter” and the accumulation rate of “sugar-cane organic matter” are estimated through 13C measurements of total soil and different organic fractions (particle-size, fractionation)

  14. Sorption of organic carbon compounds to the fine fraction of surface and Subsurface Soils

    Energy Technology Data Exchange (ETDEWEB)

    Jagadamma, Sindhu [ORNL; Mayes, Melanie [ORNL; Zinn, Yuri [Federal University of Lavras, Brazil; Gisladottir, Gudrun [University of Iceland; Ann, Russell [Iowa State University

    2014-01-01

    Dissolved organic carbon (DOC) transported from the soil surface is stabilized in deeper soil profiles by physicochemical sorption processes. However, it is unclear how different forms of organic carbon (OC) compounds common in soil organic matter interact with soil minerals in the surface (A) and subsurface (B) horizons. We added four compounds (glucose, starch, cinnamic acid and stearic acid) to the silt- and clay-sized fraction (fine fraction) of A and B horizons of eight soils from varying climates (3 temperate, 3 tropical, 1 arctic and 1 sub-arctic). Equilibriumbatch experiments were conducted using 0 to 100 mg C L 1 of 14C-labeled compounds for 8 h. Sorption parameters (maximum sorption capacity, Qmax and binding coefficient, k) calculated by fitting sorption data to the Langmuir equation showed that Qmax of A and B horizons was very similar for all compounds. Both Qmax and k values were related to sorbate properties, with Qmax being lowest for glucose (20 500 mg kg 1), highest for stearic acid (20,000 200,000 mg kg 1), and intermediate for both cinnamic acid (200 4000 mg kg 1) and starch (400 6000 mg kg 1). Simple linear regression analysis revealed that physicochemical properties of the sorbents influenced the Qmax of cinnamic acid and stearic acid, but not glucose and starch. The sorbent properties did not show predictive ability for binding coefficient k. By using the fine fraction as sorbent, we found that the mineral fractions of A horizons are equally reactive as the B horizons irrespective of soil organic carbon content.

  15. Dry anaerobic digestion of the organic fraction of municipal solid waste.

    OpenAIRE

    ten Brummeler, E.

    1993-01-01

    Anaerobic digestion is an attractive technology for solid waste management. This thesis describes the technological potentials of dry anaerobic digestion of the organic fraction of Municipal Solid Waste (MSW) using batch systems. In 1985 a research programme was started to develop the so- called BIOCEL system based on batchwise anaerobic digestion yielding biogas and compost. The research programme was financially supported by the Dutch National Programme for reuse of Waste (NOH), which is co...

  16. Storage and transformation of organic matter fractions in cryoturbated permafrost soils across the Siberian Arctic

    Directory of Open Access Journals (Sweden)

    N. Gentsch

    2015-02-01

    Full Text Available In permafrost soils, the temperature regime and the resulting cryogenic processes are decisive for the storage of organic carbon (OC and its small-scale spatial variability. For cryoturbated soils there is a lack in the assessment of pedon-scale heterogeneity in OC stocks and the transformation of functionally different organic matter (OM fractions such as particulate and mineral-associated OM. Therefore, pedons of 28 Turbels across the Siberian Arctic were sampled in five meter wide soil trenches in order to calculate OC and total nitrogen (TN stocks within the active layer and the upper permafrost based on digital profile mapping. Density fractionation of soil samples was performed to distinguish particulate OM (light fraction, LF, −3, mineral associated OM (heavy fraction, HF, >1.6 g cm−3, and a mobilizable dissolved pool (mobilizable fraction, MoF. Mineral-organic associations were characterized by selective extraction of pedogenic Fe and Al oxides and the clay composition was analyzed by X-ray diffraction. Organic matter transformation in bulk soil and density fractions was assessed by the stable carbon isotope ratio (δ13C and element contents (C and N. Across all investigated soil profiles, total OC stocks were calculated to 20.2 ± 8.0 kg m−2 (mean ± SD to 100 cm soil depth. Of this average, 54% of the OC was located in active layer horizons (annual summer thawing layer showing evidence of cryoturbation, and another 35% was present in the permafrost. The HF-OC dominated the overall OC stocks (55% followed by LF-OC (19% in mineral and 13% in organic horizons. During fractionation about 13% of the OC was released as MoF, which likely represents the most bioavailable OM pool. Cryogenic activity combined with an impaired biodegradation in topsoil horizons (O and A horizons were the principle mechanisms to sequester large OC stocks in the subsoil (16.4 ± 8.1 kg m−2; all mineral B, C, and permafrost horizons. About 22% of the subsoil

  17. Using small meshed collecting bags on trawls to quantify trawls seabed disturbance of aquatic organisms

    DEFF Research Database (Denmark)

    Krag, Ludvig Ahm

    NGOs have become active at uncovering and illustrating potential problems of the environmental and ecosystem impacts of fishing activities, especially demersal trawling, exerting considerable pressure on decision makers and subsequently, fisheries. The environmental impact of demersal trawling...... of organisms that encounter the trawl, but are not retained by it. Such catch represents an unaccounted trawl disturbance of the organisms associated with the seabed. In combination with knowledge on behavior and habitat utilization of these organisms, their presence can be used to indicate differences...... in the mechanical effect, such as penetration depth of the ground gear of different trawl designs. Collecting bags are also mounted to the different sections of the trawl in pairs, one to collect the organisms that pass through the trawl meshes and one to collect the population. Standard selectivity analyses...

  18. The effect of organic and inorganic aqueous uranium speciation on U(VI) bioavailability to an aquatic invertebrate

    Science.gov (United States)

    Fuller, C.; Croteau, M. N.; Campbell, K. M.; Cain, D.; Aiken, G.

    2015-12-01

    Growing world-wide demand for uranium (U) as an energy source has raised concerns of the human and ecological risks of U extraction and processing in the United States. Because of limited information on the relationship between U speciation and bioavailability, particularly in aquatic animals, we are characterizing U uptake by a model freshwater invertebrate (the snail Lymnaea stagnalis). This species grazes on biofilms and is thus key in the trophic transfer of contaminants through aquatic food webs. We determined the bioavailability of dissolved U(VI) over a range of water hardness, pH (6 to 8), and the presence of dissolved natural organic matter (NOM) as a competing ligand, to test the effect of aqueous speciation on uptake. Bioavailability was assessed using U uptake rate constants (kuw) derived from a kinetic bioaccumulation model. Dissolved U (1 to 1000 nM) was bioavailable over the range of geochemical conditions tested with kuw (L/g/d) decreasing with increasing dissolved Ca and with increasing pH. For example, kuw decreased from 1.6 to 0.3 as dissolved Ca was increased from 0.04 to 1.5 mM, suggesting competition between bioavailable U(VI) species and strong ternary calcium uranyl carbonato complexes. At pH 7.5 in synthetic moderately hard freshwater, kuw decreased from 0.22 in the absence of NOM to 0.07 in the presence of a hydrophobic acid NOM isolate of high aromaticity (SUVA = 5) consistent with strong aqueous complexation of U(VI) by the NOM. The co-variance of U uptake and aqueous U species distribution is being analyzed to determine which U species are bioavailable. U speciation in systems with NOM is calculated using conditional U-NOM binding constants derived by equilibrium dialysis ligand exchange methodology. The bioavailability of dietborne U is being tested since dietary metal uptake prevails for many aquatic species. These experiments include addition of ferrihydrite with U sorbed, both in the presence and absence of NOM, and mixed with diet.

  19. Contribution of different effluent organic matter fractions to membrane fouling in ultrafiltration of treated domestic wastewater

    KAUST Repository

    Zheng, Xing

    2012-12-01

    In the present work, effluent organic matter (EfOM) in treated domestic wastewater was separated into hydrophobic neutrals, colloids, hydrophobic acids, transphilic acids and neutrals and hydrophilic compounds. Their contribution to dissolved organic carbon (DOC) was identified. Further characterization was conducted with respect to molecular size and hydrophobicity. Each isolated fraction was dosed into salt solution to identify its fouling potential in ultrafiltration (UF) using a hydrophilized polyethersulfone membrane. The results show that each kind of EfOM leads to irreversible fouling. At similar delivered DOC load to the membrane, colloids present the highest fouling effect in terms of both reversible and irreversible fouling. The hydrophobic organics show much lower reversibility than the biopolymers present. However, as they are of much smaller size than the membrane pore opening, they cannot lead to such severe fouling as biopolymers do. In all of the isolated fractions, hydrophilics show the lowest fouling potential. For either colloids or hydrophobic substances, increasing their content in feedwater leads to worse fouling. The co-effect between biopolymers and other EfOM fractions has also been identified as one of the mechanisms contributing to UF fouling in filtering EfOM-containing waters. © IWA Publishing 2012.

  20. Size fractionation characterisation of removed organics in reverse osmosis concentrates by ferric chloride.

    Science.gov (United States)

    Bagastyo, A Y; Keller, J; Batstone, D J

    2011-01-01

    Reverse osmosis membrane separation is the leading method for manufacturing potable purified water. It also produces a concentrate stream, namely reverse osmosis concentrates (ROC), with 10-20% of the water, and almost all other compounds. One method for further treating this stream is by coagulation with ferric chloride. This study evaluates removed organics in ROC treated with ferric chloride. Fractionation with ultrafiltration membranes allows separation of organics based on a nominal molecular weight. A stirred cell system was applied for serial fractionation to classify organic compounds into six groups of 10 kDa. The study found that raw ROC is rich in low molecular weight compounds (organics. These compounds include soluble microbial products (SMPs) and smaller humic and fulvic acids as indicated by fluorescence scanning. Conversely, colour was mostly contributed by medium to large molecules of humic and fulvic acids (> 0.5 kDa). Organics and colour were reduced in all molecular groups at an optimum treatment dose 1.48 mM FeCl3 and a pH of 5. However, ferric seemed to effectively remove colour in all size ranges while residual nitrogen was found mostly in the < 1 kDa sizes. Further, the fluorescence indicated that larger humic and fulvic acids were removed with considerable SMPs remaining in the < 0.5 kDa.

  1. Co-Digestion of the Organic Fraction of Municipal Waste With Other Waste Types

    DEFF Research Database (Denmark)

    Hartmann, H.; Angelidaki, Irini; Ahring, Birgitte Kiær

    2002-01-01

    Several characteristics make anaerobic digestion of the organic fraction of municipal solid waste (OFMSW) difficult. By co-digestion of OFMSW with several other waste types it will be possible to optimize the anaerobic process by waste management. The co-digestion concept involves the treatment...... of several waste types in a single treatment facility. By combining many types of waste it will be possible to treat a wider range of organic waste types by the anaerobic digestion process (figure 1). Furthermore, co-digestion enables the treatment of organic waste with a high biogas potential that makes...... becomes a valuable resource. Co-digestion treatment has been successfully applied to several agricultural and industrial organic waste types in recent years. In Denmark, for example, the co-digestion concept has been successfully used since the mid 1980’s for the treatment of livestock waste...

  2. Fate of lignin, cutin and suberin in soil organic matter fractions - an incubation experiment

    Science.gov (United States)

    Mueller, Carsten W.; Mueller, Kevin E.; Freeman, Katherine H.; Ingrid, Kögel-Knabner

    2010-05-01

    The turnover of soil organic matter (SOM) is controlled by its chemical composition, its spatial accessibility and the association with the mineral phase. Separation of bulk soils by physical fractionation and subsequent chemical analysis of these fractions should give insights to how compositional differences in SOM drive turnover rates of different size-defined carbon pools. The main objective of this study was to elucidate the relative abundance and recalcitrance of lignin, cutin and suberin in aggregated bulk soils and SOM fractions in the course of SOM decomposition. Bulk soils and physically-separated size fractions (sand, silt and clay) of the Ah horizon of a forest soil (under Picea abies L.Karst) were parallel incubated over a period of one year. In order to differentiate between particulate OM (POM) and mineral-associated SOM the particle size fractions were additionally separated by density after the incubation experiment. We used solid-state 13C-CPMAS NMR spectroscopy and GC-MS (after copper oxide oxidation and solvent extraction) to analyze the composition of the incubated samples. The abundance and isotopic composition (including 13C and 14C) of the respired CO2 further enabled us to monitor the dynamics of SOM mineralization. This approach allowed for differentiating between C stabilization of soil fractions due to accessibility/aggregation and to biochemical recalcitrance at different scales of resolution (GC-MS, NMR). We found a relative enrichment of alkyl C and decreasing lignin contents in the order of sand NMR spectroscopy and GC-MS within soils and fractions before the incubation, resulting in increased lipid to lignin ratios with decreasing particle size. An accumulation of aliphatic C compounds was especially found for the small silt and clay sized particulate OM (POM). For the fresh particulate OM (POM) of the sand fraction a clear decay of lignin was observed in the course of the incubation experiment, indicated by decreasing C/V and

  3. Using operational and defined fractions to assess soil organic matter stabilization and structure

    Science.gov (United States)

    Horwath, W. R.

    2015-12-01

    Studies on soil organic matter (SOM) began with alkaline solvents revealing a dark colored substance that could be isolated under low pH. Further studies revealed fulvic and humic acids and humin fractions leading to theories on functional groups and metal-clay bridging mechanisms. The fate of isotopes in these fractions revealed soil carbon pools with varying turnover rates with half the soil carbon (C) in humin and acid hydrolyzed fractions over 1000 years old. These results are the basis of the three pool conceptual framework used in many biogeochemical models. Theories on the role of functional groups and compound classes further elaborated concepts on physical (aggregates) and chemical mechanisms of C stabilization. With the advance of analytical instrumentation, the operational fractions were further defined to the compound and molecular levels. These studies confirmed the majority of soil C is microbially derived. Our observation that all microbial groups contributed nonselectively to soil C maintenance independent of mineralogy suggests that compound characteristics within integrated structures are more important than the source of individual compounds for stabilizing soil C. In dissolved organic C floccing studies using Near Edge X-ray Fine Structure analysis, we found that aromatic compounds interacted first with Fe, however, the majority of direct bonds to Fe were polysaccharides, reinforcing that an integrative chemical structure rather than direct bonds imparted stability in organo-metal interactions. Using a novel differential scanning calorimeter coupled to an isotope ratio mass spectrometer setup, we confirmed that the presence of clays (independent of clay type) increased the microbial utilization of calcium stabilized high versus low temperature compounds, asserting that higher temperature compounds (i.e., phenolics) are likely less tightly bound by clay minerals. The integration of operational and defined fractions of SOM remains a legitimate

  4. Reactivity of Zerovalent Metals in Aquatic Media: Effects of Organic Surface Coatings

    Energy Technology Data Exchange (ETDEWEB)

    Tratnyek, Paul G.; Salter-Blanc, Alexandra; Nurmi, James; Amonette, James E.; Liu, Juan; Wang, Chong M.; Dohnalkova, Alice; Baer, Donald R.

    2011-09-02

    Granular, reactive zerovalent metals (ZVMs)—especially iron (ZVI)—form the basis for model systems that have been used in fundamental and applied studies of a wide variety of environmental processes. This has resulted in notable advances in many areas, including the kinetics and mechanisms of contaminant reduction reactions, theory of filtration and transport of colloids in porous media, and modeling of complex reactive-transport scenarios. Recent emphasis on nano-sized ZVI has created a new opportunity: to advance the understanding of how coatings of organic polyelectrolytes—like natural organic matter (NOM)—influence the reactivity of environmental surfaces. Depending on many factors, organic coatings can be activating or passivating with respect to redox reactions at particle-solution interfaces. In this study, we show the effects of organic coatings on nZVI vary with a number of factors including: (i) time (i.e., “aging” is evident not only in the structure and composition of the nZVI but also in the interactions between nZVI and NOM) and (ii) the type of organic matter (i.e., suspensions of nZVI are stabilized by NOM and the model polyelectrolyte carboxymethylcellulose (CMC), but NOM stimulates redox reactions involving nZVI while CMC inhibits them).

  5. Influence of sediment organic enrichment and water alkalinity on growth of aquatic isoetid and elodeid plants

    DEFF Research Database (Denmark)

    Raun, Ane-Marie Løvendahl; Borum, Jens; Jensen, Kaj Sand

    2010-01-01

    lakes, the vegetation has rarely regained its former composition and coverage. Patterns of recovery may depend on local alkalinity because HCO3- stimulates photosynthesis of elodeids and not of isoetids. In laboratory growth experiments with two isoetids (Lobelia dortmanna and Littorella uniflora......) increasing alkalinity (from 0.17 to 3.20 meq. L-1) enhances growth and reduces inhibition of organic sediment enrichment for elodeids but not for isoetids. 2. In low organic sediments, higher oxygen release from roots of isoetids than elodeids generated oxic conditions to greater sediment depth for Lobelia......3- addition in accordance with its use of sediment CO2. Biomass of elodeids increased severalfold by rising alkalinity from 0.17 to 3.20 meq. L-1 in accordance with their use of HCO3- for photosynthesis, while the negative impact of organically enriched sediments remained. 5. Overall, root...

  6. Distribution of Soil Organic Carbon Fractions Along the Altitudinal Gradient in Changbai Mountain, China

    Institute of Scientific and Technical Information of China (English)

    ZHANG Min; ZHANG Xiao-Ke; LIANG Wen-Ju; JIANG Yong; DAI Guan-Hua; WANG Xu-Gao; HAN Shi-Jie

    2011-01-01

    Understanding the responses of soil organic carbon (SOC) fractions to altitudinal gradient variation is important for understanding changes in the carbon balance of forest ecosystems.In our study the SOC and its fractions of readily oxidizable carbon (ROC),water-soluble carbon (WSC) and microbial biomass carbon (MBC) in the soil organic and mineral horizons were investigated for four typical forest types,including mixed coniferous broad-leaved forest (MCB),dark coniferous spruce-fir forest (DCSF),dark coniferous spruce forest (DCS),and Ermans birch forest (EB),along an altitudinal gradient in the Changbai Mountain Nature Reserve in Northeast China.The results showed that there was no obvious altitudinal pattern in the SOC.Similar variation trends of SOC with altitude were observed between the organic and mineral horizons.Significant differences in the contents of SOC,WSC,MBC and ROC were found among the four forest types and between horizons.The contents of ROC in the mineral horizon,WSC in the organic horizon and MBC in both horizons in the MCB and EB forests were significantly greater than those in either DCSF or DCS forest.The proportion of soil WSC to SOC was the lowest among the three main fractions.The contents of WSC,MBC and ROC were significantly correlated (P < 0.05) with SOC content.It can be concluded that vegetation types and climate were crucial factors in regulating the distribution of soil organic carbon fractious in Changbai Mountain.

  7. Passive Sampling in Regulatory Chemical Monitoring of Nonpolar Organic Compounds in the Aquatic Environment

    DEFF Research Database (Denmark)

    Booij, Kees; Robinson, Craig D; Burgess, Robert M;

    2016-01-01

    in water, but this definition has little scientific basis. Insufficient quality control is a present weakness of passive sampling in water. Laboratory performance studies and the development of standardized methods are needed to improve data quality and to encourage the use of passive sampling...... by commercial laboratories and monitoring agencies. Successful prediction of bioaccumulation based on passive sampling is well documented for organisms at the lower trophic levels, but requires more research for higher levels. Despite the existence of several knowledge gaps, passive sampling presently...... is the best available technology for chemical monitoring of nonpolar organic compounds. Key issues to be addressed by scientists and environmental managers are outlined....

  8. Toxicity on aquatic organisms exposed to secondary effluent disinfected with chlorine, peracetic acid, ozone and UV radiation.

    Science.gov (United States)

    da Costa, Juliana Berninger; Rodgher, Suzelei; Daniel, Luiz Antonio; Espíndola, Evaldo Luiz Gaeta

    2014-11-01

    The toxic potential of four disinfectant agents (chlorine, ozone, peracetic acid and UV radiation), used in the disinfection of urban wastewater, was evaluated with respect to four aquatic organisms. Disinfection assays were carried out with wastewater from the city of Araraquara (São Paulo State, Brazil), and subsequently, toxicity bioassays were applied in order to verify possible adverse effects to the cladocerans (Ceriodaphnia silvestrii and Daphnia similis), midge larvae Chironomus xanthus and fish (Danio rerio). Under the experimental conditions tested, all the disinfectants were capable of producing harmful effects on the test organisms, except for C. xanthus. The toxicity of the effluent to C. silvestrii was observed to increase significantly as a result of disinfection using 2.5 mg L(-1) chlorine and 29.9 mg L(-1) ozone. Ozonation and chlorination significantly affected the survival of D. similis and D. rerio, causing mortality of 60 to 100 % in comparison to the non-disinfected effluent. In experiments with effluent treated with peracetic acid (PAA) and UV radiation, a statistically significant decrease in survival was only detected for D. rerio. This investigation suggested that the study of the ideal concentrations of disinfectants is a research need for ecologically safe options for the treatment of wastewater.

  9. Facile synthesis of mosquitocidal silver nanoparticles using Mussaenda glabra leaf extract: characterisation and impact on non-target aquatic organisms.

    Science.gov (United States)

    Govindarajan, Marimuthu; Rajeswary, Mohan; Hoti, S L; Nicoletti, Marcello; Benelli, Giovanni

    2016-11-01

    Plant-borne compounds have been proposed for extracellular synthesis of mosquitocidal nanoparticles. However, their impact against mosquito natural enemies has been scarcely studied. Here, we synthesised silver nanoparticles (Ag NPs) using Mussaenda glabra leaf extract as reducing and stabilising agent. Biofabricated Ag NPs were characterised by UV-vis spectrophotometry, X-ray diffraction, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Compared to the leaf aqueous extract, biosynthesised Ag NPs showed higher toxicity against mosquito vectors Anopheles subpictus, Aedes albopictus and Culex tritaeniorhynchus with LC50 of 17-19 μg/mL, respectively. Ag NPs were found safer to non-target organisms Diplonychus indicus and Gambusia affinis, with respective LC50 values ranging from 1446 to 8628 μg/mL. Overall, M. glabra-fabricated Ag NPs are a promising and eco-friendly tool against larval populations of mosquito vectors of medical and veterinary importance, with negligible toxicity against other non-target aquatic organisms.

  10. Silver nanoparticle accumulation by aquatic organisms – neutron activation as a tool for the environmental fate of nanoparticles tracing

    Directory of Open Access Journals (Sweden)

    Asztemborska Monika

    2014-12-01

    Full Text Available Water environments are noted as being some of the most exposed to the influence of toxic nanoparticles (NPs. Therefore, there is a growing need for the investigation of the accumulation and toxicity of NPs to aquatic organisms. In our studies neutron activation followed by gamma spectrometry and liquid scintillation counting were used for studying the accumulation of silver nanoparticles (AgNPs by freshwater larvae of Chironomus and fish Danio rerio. The influence of exposition time, concentration and the source of nanoparticles on the efficiency of AgNP accumulation were studied. It was found that AgNPs are efficiently accumulated by Chironomid larvae for the first 30 hours of exposition; then, the amount of silver nanoparticles decreases. The silver content in larvae increases together with the NP concentration in water. Larvae which have accumulated AgNPs can be a source of nanoparticles for fish and certainly higher levels of Ag in the trophic chain. In comparison with water contamination, silver nanoparticles are more efficiently accumulated if fish are fed with AgNP-contaminated food. Finally, it was concluded that the applied study strategy, including neutron activation of nanoparticles, is very useful technique for tracing the uptake and accumulation of NPs in organisms

  11. Toxicity on aquatic organisms exposed to secondary effluent disinfected with chlorine, peracetic acid, ozone and UV radiation.

    Science.gov (United States)

    da Costa, Juliana Berninger; Rodgher, Suzelei; Daniel, Luiz Antonio; Espíndola, Evaldo Luiz Gaeta

    2014-11-01

    The toxic potential of four disinfectant agents (chlorine, ozone, peracetic acid and UV radiation), used in the disinfection of urban wastewater, was evaluated with respect to four aquatic organisms. Disinfection assays were carried out with wastewater from the city of Araraquara (São Paulo State, Brazil), and subsequently, toxicity bioassays were applied in order to verify possible adverse effects to the cladocerans (Ceriodaphnia silvestrii and Daphnia similis), midge larvae Chironomus xanthus and fish (Danio rerio). Under the experimental conditions tested, all the disinfectants were capable of producing harmful effects on the test organisms, except for C. xanthus. The toxicity of the effluent to C. silvestrii was observed to increase significantly as a result of disinfection using 2.5 mg L(-1) chlorine and 29.9 mg L(-1) ozone. Ozonation and chlorination significantly affected the survival of D. similis and D. rerio, causing mortality of 60 to 100 % in comparison to the non-disinfected effluent. In experiments with effluent treated with peracetic acid (PAA) and UV radiation, a statistically significant decrease in survival was only detected for D. rerio. This investigation suggested that the study of the ideal concentrations of disinfectants is a research need for ecologically safe options for the treatment of wastewater. PMID:25213288

  12. Determination of the biogenic secondary organic aerosol fraction in the boreal forest by NMR spectroscopy

    Directory of Open Access Journals (Sweden)

    E. Finessi

    2012-01-01

    Full Text Available The study investigates the sources of fine organic aerosol (OA in the boreal forest, based on measurements including both filter sampling (PM1 and online methods and carried out during a one-month campaign held in Hyytiälä, Finland, in spring 2007. Two aerosol mass spectrometers (Q-AMS, ToF-AMS were employed to measure on-line concentrations of major non-refractory aerosol species, while the water extracts of the filter samples were analyzed by nuclear magnetic resonance (NMR spectroscopy for organic functional group characterization of the polar organic fraction of the aerosol. AMS and NMR spectra were processed separately by non-negative factorization algorithms, in order to apportion the main components underlying the submicrometer organic aerosol composition and depict them in terms of both mass fragmentation patterns and functional group compositions.

    The NMR results supported the AMS speciation of oxidized organic aerosol (OOA into two main fractions, which could be generally labelled as more and less oxidized organics. The more oxidized component was characterized by a mass spectrum dominated by the m/z 44 peak, and in parallel by a NMR spectrum showing aromatic and aliphatic backbones highly substituted with oxygenated functional groups (carbonyls/carboxyls and hydroxyls. Such component, contributing on average 50% of the OA mass throughout the observing period, was associated with pollution outbreaks from the Central Europe. The less oxidized component was enhanced in concomitance with air masses originating from the North-to-West sector, in agreement with previous investigations conducted at this site. NMR factor analysis was able to separate two distinct components under the less oxidized fraction of OA. One of these NMR-factors was associated with the formation of terrestrial biogenic secondary organic aerosol (BSOA, based on the comparison with spectral profiles obtained from laboratory experiments of

  13. Determination of the biogenic secondary organic aerosol fraction in the boreal forest by NMR spectroscopy

    Science.gov (United States)

    Finessi, E.; Decesari, S.; Paglione, M.; Giulianelli, L.; Carbone, C.; Gilardoni, S.; Fuzzi, S.; Saarikoski, S.; Raatikainen, T.; Hillamo, R.; Allan, J.; Mentel, Th. F.; Tiitta, P.; Laaksonen, A.; Petäjä, T.; Kulmala, M.; Worsnop, D. R.; Facchini, M. C.

    2012-01-01

    The study investigates the sources of fine organic aerosol (OA) in the boreal forest, based on measurements including both filter sampling (PM1) and online methods and carried out during a one-month campaign held in Hyytiälä, Finland, in spring 2007. Two aerosol mass spectrometers (Q-AMS, ToF-AMS) were employed to measure on-line concentrations of major non-refractory aerosol species, while the water extracts of the filter samples were analyzed by nuclear magnetic resonance (NMR) spectroscopy for organic functional group characterization of the polar organic fraction of the aerosol. AMS and NMR spectra were processed separately by non-negative factorization algorithms, in order to apportion the main components underlying the submicrometer organic aerosol composition and depict them in terms of both mass fragmentation patterns and functional group compositions. The NMR results supported the AMS speciation of oxidized organic aerosol (OOA) into two main fractions, which could be generally labelled as more and less oxidized organics. The more oxidized component was characterized by a mass spectrum dominated by the m/z 44 peak, and in parallel by a NMR spectrum showing aromatic and aliphatic backbones highly substituted with oxygenated functional groups (carbonyls/carboxyls and hydroxyls). Such component, contributing on average 50% of the OA mass throughout the observing period, was associated with pollution outbreaks from the Central Europe. The less oxidized component was enhanced in concomitance with air masses originating from the North-to-West sector, in agreement with previous investigations conducted at this site. NMR factor analysis was able to separate two distinct components under the less oxidized fraction of OA. One of these NMR-factors was associated with the formation of terrestrial biogenic secondary organic aerosol (BSOA), based on the comparison with spectral profiles obtained from laboratory experiments of terpenes photo-oxidation. The second NMR

  14. Micro-treatment options for components of organic fraction of MSW in residential areas.

    Science.gov (United States)

    Chanakya, H N; Ramachandra, T V; Guruprasad, M; Devi, Vinuta

    2007-12-01

    There is a growing interest in management of MSW through micro-treatment of organic fraction of municipal solid wastes (OFMSW) in many cities of India. The OFMSW fraction is high (>80%) in many pockets within South Indian cities like Bangalore, Chikkamagalur, etc. and is largely represented by vegetable, fruit, packing and garden wastes. Among these, the last three have shown problems for easy decomposition. Fruit wastes are characterized by a large pectin supported fraction that decomposes quickly to organic acids (becomes pulpy) that eventually slow down anaerobic and aerobic decomposition processes. Paper fraction (newsprint and photocopying paper) as well as paddy straw (packing), bagasse (from cane juice stalls) and tree leaf litter (typical garden waste and street sweepings) are found in reasonably large proportions in MSW. These decompose slowly due to poor nutrients or physical state. We have examined the suitability of these substrates for micro-composting in plastic bins by tracking decomposition pattern and physical changes. It was found that fruit wastes decompose rapidly to produce organic acids and large leachate fraction such that it may need to be mixed with leachate absorbing materials (dry wastes) for good composting. Leaf litter, paddy straw and bagasse decompose to the tune of 90, 68 and 60% VS and are suitable for composting micro-treatment. Paper fractions even when augmented with 10% leaf compost failed to show appreciable decomposition in 50 days. All these feedstocks were found to have good biological methane potential (BMP) and showed promise for conversion to biogas under a mixed feed operation. Suitability of this approach was verified by operating a plug-flow type anaerobic digester where only leaf litter gathered nearby (as street sweepings) was used as feedstock. Here only a third of the BMP was realized at this scale (0.18 m(3 )biogas/kg VS 0.55 m(3)/kg in BMP). We conclude that anaerobic digestion in plug-flow like digesters appear

  15. Toxicity of environmental chemicals and their mixtures to selected aquatic organisms. Behaviour, development and biochemistry; Toxizitaet von Umweltchemikalien und deren Mischungen auf ausgewaehlte aquatische Organismen. Verhalten, Entwicklung und Biochemie

    Energy Technology Data Exchange (ETDEWEB)

    Kienle, Cornelia

    2009-04-28

    In this work, the effects of various single substances (pesticides and metals) as well as binary mixtures of them on zebrafish (Danio rerio) embryos and larvae were assessed on biochemical, developmental, and organism levels. The influence of oxygen depletion on the toxicity of substances was included as an additional interacting factor. To analyse complex interactions, the predator-prey behaviour between zebrafish and chironomid larvae (Chironomus riparius) was investigated. Another aspect of this work were studies on complex mixtures of hydrocarbons such as the water accommodated fraction of crude oil, and their effects on the behaviour of marine amphipods (Corophium volutator), as well as semi-field experiments with freshwater amphipods (Gammarus pulex). My investigations showed that effects of various substances in environmentally relevant concentration ranges are exerted on different levels of biological organisation, both in amphipods and fish. It could be shown that abiotic parameters modify the effects of pollutants. When investigating mixtures of substances with similar or different modes of action, additivity occurred in the majority of cases which usually were consistent for all investigated parameters (enzyme activity, locomotor activity, developmental impairment, mortality). Effects of the neurotoxic insecticide chlorpyrifos on the interactions between fish and chironomids could be detected in environmentally relevant concentration ranges. The effects of the water accommodated fraction of crude oil which represents a great risk for aquatic organisms in costal habitats were displayed by alterations in the behaviour of the marine amphipod Corophium volutator. For a continuous monitoring of water quality in monitoring stations, the resident amphipod Gammarus pulex proved to be a suitable and relevant test organism, as it responds sensitive to complex mixtures of pollutants in surface waters. In summary, behavioural parameters proved to be integrative

  16. Radiocarbon and stable carbon isotope compositions of chemically fractionated soil organic matter in a temperate-zone forest

    International Nuclear Information System (INIS)

    To better understand the role of soil organic matter in terrestrial carbon cycle, carbon isotope compositions in soil samples from a temperate-zone forest were measured for bulk, acid-insoluble and base-insoluble organic matter fractions separated by a chemical fractionation method. The measurements also made it possible to estimate indirectly radiocarbon (14C) abundances of acid- and base-soluble organic matter fractions, through a mass balance of carbon among the fractions. The depth profiles of 14C abundances showed that (1) bomb-derived 14C has penetrated the first 16 cm mineral soil at least; (2) Δ14C values of acid-soluble organic matter fraction are considerably higher than those of other fractions; and (3) a significant amount of the bomb-derived 14C has been preserved as the base-soluble organic matter around litter-mineral soil boundary. In contrast, no or little bomb-derived 14C was observed for the base-insoluble fraction in all sampling depths, indicating that this recalcitrant fraction, accounting for approximately 15% of total carbon in this temperate-zone forest soil, plays a role as a long-term sink in the carbon cycle. These results suggest that bulk soil organic matter cannot provide a representative indicator as a source or a sink of carbon in soil, particularly on annual to decadal timescales

  17. Methodologies to assess the fate of polar organic compounds in aquatic environments

    OpenAIRE

    Magnér, Jörgen

    2010-01-01

    Polar organic compounds (POCs) are chemicals with polar functional groups in their structure. The functional groups make the compounds hydrophilic and less prone to partition with biota. However, the knowledge of their fate is limited due to difficulties associated with their measurements. Although, the persistence of POCs in the environment is generally low, they are considered to be semi-persistent compounds due to their continuous introduction to the environment via wastewater. Studies hav...

  18. Tetrodotoxin--distribution and accumulation in aquatic organisms, and cases of human intoxication.

    Science.gov (United States)

    Noguchi, Tamao; Arakawa, Osamu

    2008-05-28

    Many pufferfish of the family Tetraodontidae possess a potent neurotoxin, tetrodotoxin (TTX). In marine pufferfish species, toxicity is generally high in the liver and ovary, whereas in brackish water and freshwater species, toxicity is higher in the skin. In 1964, the toxin of the California newt was identified as TTX as well, and since then TTX has been detected in a variety of other organisms. TTX is produced primarily by marine bacteria, and pufferfish accumulate TTX via the food chain that begins with these bacteria. Consequently, pufferfish become non-toxic when they are fed TTX-free diets in an environment in which the invasion of TTX-bearing organisms is completely shut off. Although some researchers claim that the TTX of amphibians is endogenous, we believe that it also has an exogenous origin, i.e., from organisms consumed as food. TTX-bearing animals are equipped with a high tolerance to TTX, and thus retain or accumulate TTX possibly as a biologic defense substance. There have been many cases of human intoxication due to the ingestion of TTX-bearing pufferfish, mainly in Japan, China, and Taiwan, and several victims have died. Several cases of TTX intoxication due to the ingestion of small gastropods, including some lethal cases, were recently reported in China and Taiwan, revealing a serious public health issue.

  19. Development and validation of an in-house quantitative analysis method for cylindrospermopsin using hydrophilic interaction liquid chromatography-tandem mass spectrometry: Quantification demonstrated in 4 aquatic organisms.

    Science.gov (United States)

    Esterhuizen-Londt, Maranda; Kühn, Sandra; Pflugmacher, Stephan

    2015-12-01

    The cyanobacterial toxin cylindrospermopsin (CYN) is of great concern in aquatic environments because of its incidence, multiple toxicity endpoints, and, therefore, the severity of health implications. It may bioaccumulate in aquatic food webs, resulting in high exposure concentrations to higher-order trophic levels, particularly humans. Because of accumulation at primary levels resulting from exposure to trace amounts of toxin, a sensitive analytical technique with proven aquatic applications is required. In the present study, a hydrophilic interaction liquid chromatographic-tandem mass spectrometric method with a lower limit of detection of 200 fg on column (signal-to-noise ratio = 3, n = 9) and a lower limit of quantification of 1 pg on column (signal-to-noise ratio = 11, n = 9) with demonstrated application in 4 aquatic organisms is described. The analytical method was optimized and validated with a linear range (r(2) = 0.999) from 0.1 ng mL(-1) to 100 ng mL(-1) CYN. Mean recovery of the extraction method was 98 ± 2%. Application of the method was demonstrated by quantifying CYN uptake in Scenedesmus subspicatus (green algae), Egeria densa (Brazilian waterweed), Daphnia magna (water flea), and Lumbriculus variegatus (blackworm) after 24 h of static exposure to 50 μg L(-1) CYN. Uptake ranged from 0.05% to 0.11% of the nominal CYN exposure amount. This constitutes a sensitive and reproducible method for extraction and quantification of unconjugated CYN with demonstrated application in 4 aquatic organisms, which can be used in further aquatic toxicological investigations. PMID:26126753

  20. Development and validation of an in-house quantitative analysis method for cylindrospermopsin using hydrophilic interaction liquid chromatography-tandem mass spectrometry: Quantification demonstrated in 4 aquatic organisms.

    Science.gov (United States)

    Esterhuizen-Londt, Maranda; Kühn, Sandra; Pflugmacher, Stephan

    2015-12-01

    The cyanobacterial toxin cylindrospermopsin (CYN) is of great concern in aquatic environments because of its incidence, multiple toxicity endpoints, and, therefore, the severity of health implications. It may bioaccumulate in aquatic food webs, resulting in high exposure concentrations to higher-order trophic levels, particularly humans. Because of accumulation at primary levels resulting from exposure to trace amounts of toxin, a sensitive analytical technique with proven aquatic applications is required. In the present study, a hydrophilic interaction liquid chromatographic-tandem mass spectrometric method with a lower limit of detection of 200 fg on column (signal-to-noise ratio = 3, n = 9) and a lower limit of quantification of 1 pg on column (signal-to-noise ratio = 11, n = 9) with demonstrated application in 4 aquatic organisms is described. The analytical method was optimized and validated with a linear range (r(2) = 0.999) from 0.1 ng mL(-1) to 100 ng mL(-1) CYN. Mean recovery of the extraction method was 98 ± 2%. Application of the method was demonstrated by quantifying CYN uptake in Scenedesmus subspicatus (green algae), Egeria densa (Brazilian waterweed), Daphnia magna (water flea), and Lumbriculus variegatus (blackworm) after 24 h of static exposure to 50 μg L(-1) CYN. Uptake ranged from 0.05% to 0.11% of the nominal CYN exposure amount. This constitutes a sensitive and reproducible method for extraction and quantification of unconjugated CYN with demonstrated application in 4 aquatic organisms, which can be used in further aquatic toxicological investigations.

  1. Daphnia as a model organism in limnology and aquatic biology: some aspects of its reproduction and development

    Directory of Open Access Journals (Sweden)

    Adam Petrusek

    2011-08-01

    Full Text Available Invertebrates comprise the overwhelming majority of all animal species - around 95% of described species, not including substantial cryptic variation. As it is an extremely diverse and heterogeneous group, research on various invertebrate taxa often follows parallel trajectories, with little interaction among experts on different groups. To promote sharing of knowledge within as well as across taxa, the International Society of Invertebrate Reproduction and Development (ISIRD was established in 1975 in Calicut, India. Since that time, the ISIRD has organised international conferences at three-year intervals where various aspects of invertebrate biology are presented and discussed, naturally with the focus on reproduction and development. Traditionally, marine invertebrate groups have been well represented at all ISIRD congresses, but freshwater invertebrates have often been relatively overlooked at these meetings. The 12th ISIRD congress took place between August 16 and 20, 2010 in Prague, the Czech Republic. Several different Czech institutions collaborated on the organisation of this meeting. As aquatic invertebrate research has a long tradition in the country, we decided to include a section dedicated to popular model organisms in aquatic ecology and evolutionary biology, the "water fleas", cladocerans of the genus Daphnia. The section entitled "Daphnia and other cladocerans as model organisms" was open to any aspects of cladoceran biology directly or indirectly related to their reproduction or development. Unfortunately, the timing of the Prague congress completely overlapped the triennial congress of the International Society of Theoretical and Applied Limnology (SIL in Cape Town, South Africa. This large meeting in a very attractive setting attracted many cladocerologists from all over the world, including Europe. Therefore, the Daphnia section of the Prague ISIRD meeting remained moderate in size, attracting 13 contributions (eight talks

  2. Analytical modelling of stable isotope fractionation of volatile organic compounds in the unsaturated zone

    CERN Document Server

    Bouchard, D; Höhener, P; Hunkeler, D; 10.1016/j.jconhyd.2010.09.006

    2011-01-01

    Analytical models were developed that simulate stable isotope ratios of volatile organic compounds (VOCs) near a point source contamination in the unsaturated zone. The models describe diffusive transport of VOCs, biodegradation and source ageing. The mass transport is governed by Fick's law for diffusion, and the equation for reactive transport of VOCs in the soil gas phase was solved for different source geometries and for different boundary conditions. Model results were compared to experimental data from a one-dimensional laboratory column and a radial-symmetric field experiment, and the comparison yielded a satisfying agreement. The model results clearly illustrate the significant isotope fractionation by gas-phase diffusion under transient state conditions. This leads to an initial depletion of heavy isotopes with increasing distance from the source. The isotope evolution of the source is governed by the combined effects of isotope fractionation due to vaporization, diffusion and biodegradation. The net...

  3. Dissolved organic matter: Fractional composition and sorbability by the soil solid phase (Review of literature)

    Science.gov (United States)

    Karavanova, E. I.

    2013-08-01

    The behavior of dissolved organic matter (DOM) in soils under varying environmental conditions represents a poorly studied aspect of the problem of organic matter loss from soils. The equilibrium and sustainable development of ecosystems in the northern latitudes are largely determined by the balance between the formation of DOM, its accumulation in the lower soil horizons, and its input with runoff into surface waters. The residence time, retention strength in the soil, and thermodynamic and biochemical stabilities depend on the localization of DOM in the pore space and its chemical structure. Amphiphilic properties represent a valuable diagnostic parameter, which can be used to predict the behavior of DOM in the soil. Acidic components of hydrophobic and hydrophilic nature constitute the major portion of DOM in forest soils of the temperate zone. The hydrophilic fraction includes short-chain aliphatic carboxylic acids, hydrocarbons, and amino acids and is poorly sorbed by the solid phase. However, the existence of this fraction in soil solution is also limited both in space (in the finest pores) and time because of higher accessibility to microbial degradation. The hydrophilic fraction composes the major portion of labile DOM in soils. The hydrophobic fraction consists of soluble degradation products of lignin; it is enriched in structural ortho-hydroxybenzene fragments, which ensure its selective sorption and strong retention in soils. Sorption is favored by low pH values (3.5-5), the high ionic strength of solution, the heavy texture and fine porous structure of soil, the high contents of oxalate- and dithionite-soluble iron (and aluminum) compounds, and hydrological conditions characterized by slow water movement. The adsorbed DOM is chemically and biochemically recalcitrant and significantly contributes to the humus reserves in the low mineral horizons of soils.

  4. Adsorption of Different Fractions of Organic Matter on the Surface of Metal Oxide

    KAUST Repository

    Zaouri, Noor A

    2013-05-18

    The adsorption of different fractions of organic matter on the surface of Al2O3 and ZrO2 were investigated. The aim was to study the affinity of these fractions on the surface of metal oxide and the effect of several factors. Batch adsorption experiments were conducted with Low molecular weight oxygenated compounds. These chemical compound have been chosen to investigate:1) the aliphatic and aromatic structurer;2)contribution of hydroxyl group and; 3) the number of carboxyl group. HPLC and IC analysis used for determent the concentration of these chemical in the working solution. ATR-FTIR used to distinguish the type of coordination structure with the surface of metal oxide. The results fitted with Langmuir equation. The results showed that the chemical structure and the type and number of attached functional have an impact on the adsorption. Which it was proved via ATR-FTIR where the result showed that each chemical have different coordination structure on the surface of ZrO2 and Al2O3. Different fractions and sources of NOM were used (hydrophobic fraction of Suwannee and Colorado River, biopolymers extracted for the exuded of 2 species of algae, and low molecular acids that do not adsorb in XAD-8 resin). Results showed that these different fractions have different affinity with the surface of Al2O3 and ZrO2. These adsorption behaviors were varying according to the difference in the component of each NOM. Biopolymers showed significant adsorption at acidic pH. These biopolymers are mainly comprised of polysaccharides and this result proved that polysaccharide adsorb on the surface of ZrO2 more than Al2O3.

  5. Effect of AL2O3 and TiO2 nanoparticles on aquatic organisms

    Science.gov (United States)

    Gosteva, I.; Morgalev, Yu; Morgaleva, T.; Morgalev, S.

    2015-11-01

    Environmental toxicity of aqueous disperse systems of nanoparticles of binary compounds of titanium dioxides (with particle size Δ50=5 nm, Δ50=50 nm, Δ50=90 nm), aluminum oxide alpha-forms (Δ50=7 nm and Δ50=70 nm) and macro forms (TiO2 Δ50=350 nm, Al2O3 A50=4000 nm) were studied using biological testing methods. The bioassay was performed using a set of test organisms representing the major trophic levels. We found the dependence of the toxic effect concentration degree of nTiO2 and nAl2O3 on the fluorescence of the bacterial biosensor "Ekolyum", the chemotactic response of ciliates Paramecium caudatum, the growth of unicellular algae Chlorella vulgaris Beijer and mortality of entomostracans Daphnia magna Straus. We revealed the selective dependence of nTiO2 and nAl2O3 toxicity on the size, concentration and chemical nature of nanoparticles. The minimal concentration causing an organism's response on nTiO2 and nAl2O3 effect depends on the type of the test- organism and the test reaction under study. We specified L(E)C50 and acute toxicity categories for all the studied nanoparticles. We determined that nTiO2 (Δ50=5 nm) belong to the category «Acute toxicity 1», nTiO2 (A50=90 nm) and nAl2O3 (Δ50=70 nm) - to the category «Acute toxicity 2», nAl2O3 (Δ50=7 nm) - to the category «Acute toxicity 3». No acute toxicity was registered for nTiO2 (Δ50=50 nm) and macro form TiO2.

  6. The mode of action of isocyanide in three aquatic organisms, Balanus amphitrite, Bugula neritina and Danio rerio.

    Directory of Open Access Journals (Sweden)

    Yi-Fan Zhang

    Full Text Available Isocyanide is a potential antifouling compound in marine environments. In this study, we investigated its mode of action in three aquatic organisms. Two of them, the bryozoan Bugula neritina and the barnacle Balanus amphitrite, are major marine fouling invertebrates, and the other organism is the non-target species zebrafish Danio rerio. In the swimming larvae of B. neritina, isocyanide did not affect the total attachment rate (≤50 µg ml(-1, but it did change the attachment site by increasing the percentage of attachment on the bottom of the container rather than on the wall or air-water inter-surface. Isocyanide binds several proteins in B. neritina as identified via SDS-PAGE-LC-MS/MS: 1 a 30 kD protein band containing two proteins similar to voltage dependent anion channels (VDAC, which control the direct coupling of the mitochondrial matrix to the energy maintenance of the cytosol and the release of apoptogenic factors from mitochondria of mammalian cells; and 2 an unknown 39 kD protein. In B. amphitrite cyprids, the isocyanide binding protein were 1 a protein similar to NADH-ubiquinone oxidoreductase, which is the "entry enzyme" of oxidative phosphorylation in mitochondria; and 2 cytochrome P450. In Danio rerio embryos, isocyanide caused "wavy" notochords, hydrocephalus, pericardial edema, poor blood circulation, and defects in pigmentation and hematopoiesis, which phenocopied copper deficiency. This is the first report on isocyanide binding proteins in fouling organisms, as well as the first description of its phenotype and potential toxicology in zebrafish.

  7. The Mode of Action of Isocyanide in Three Aquatic Organisms, Balanus amphitrite, Bugula neritina and Danio rerio

    KAUST Repository

    Zhang, Yi-Fan

    2012-09-18

    Isocyanide is a potential antifouling compound in marine environments. In this study, we investigated its mode of action in three aquatic organisms. Two of them, the bryozoan Bugula neritina and the barnacle Balanus amphitrite, are major marine fouling invertebrates, and the other organism is the non-target species zebrafish Danio rerio. In the swimming larvae of B. neritina, isocyanide did not affect the total attachment rate (≤50 µg ml^(−1)), but it did change the attachment site by increasing the percentage of attachment on the bottom of the container rather than on the wall or air-water inter-surface. Isocyanide binds several proteins in B. neritina as identified via SDS-PAGE-LC-MS/MS: 1) a 30 kD protein band containing two proteins similar to voltage dependent anion channels (VDAC), which control the direct coupling of the mitochondrial matrix to the energy maintenance of the cytosol and the release of apoptogenic factors from mitochondria of mammalian cells; and 2) an unknown 39 kD protein. In B. amphitrite cyprids, the isocyanide binding protein were 1) a protein similar to NADH-ubiquinone oxidoreductase, which is the “entry enzyme” of oxidative phosphorylation in mitochondria; and 2) cytochrome P450. In Danio rerio embryos, isocyanide caused “wavy” notochords, hydrocephalus, pericardial edema, poor blood circulation, and defects in pigmentation and hematopoiesis, which phenocopied copper deficiency. This is the first report on isocyanide binding proteins in fouling organisms, as well as the first description of its phenotype and potential toxicology in zebrafish.

  8. Paired-organ and other selected absorbed fraction for the Korean Reference Adult Male model

    International Nuclear Information System (INIS)

    The authors have developed a mathematical model for calculating internal radionuclide dosimetry for the Korean Reference Adult Male, and have also derived paired-organ and other selected inter-organ photon-specific absorbed fractions for this model. Each lung, kidney and adrenal gland was set as a separate source region even though each of them shares an identical physiological function with their complementary half. The thyroid gland was also set as a source region. Specific absorbed fractions (SAFs) were then derived by selecting 10 photon energies from 0.02 to 4.0 MeV inclusive. For this purpose the Monte Carlo methodology was used, and the derived SAF was compared with the resulting value of MIRD Pamphlet No. 5 and ORNL TM-8381, both of which were derived on the basis of the ICRP-23 reference man. The comparison showed that MIRD No. 5 and ORNL TM-8381 resulted in a higher absorbed fraction, but the phantom created on the basis of the Korean reference man led to a higher SAF. The weight of the organs of the phantom, and the size and location of the trunk seem to account for the differences. The energy-dependent differences in the SAFs are considered to be related to the distance between the source and target regions, the composition of the intervening tissues, and the photon energies and mean free paths. Also, as a result of deriving SAFs after setting each separate lung, kidney and adrenal gland as a source region, it was found that, although they are of the same physiological function, each individual organ serves as a source region on its own. Differences were noted in SAFs exerted on the source and target organs in accordance with the location of the organs, that is, whether they were located to the left or right of the source organs. The SAF derived in this study can be used for a more accurate internal radionuclide dosimetry for Koreans and other Orientals whose physiology, lifestyle and dietary habits are similar to those of Koreans. (authors)

  9. Estimation of the Risks of Collision or Strike to Freshwater Aquatic Organisms Resulting from Operation of Instream Hydrokinetic Turbines

    Energy Technology Data Exchange (ETDEWEB)

    Schweizer, Peter E [ORNL; Cada, Glenn F [ORNL; Bevelhimer, Mark S [ORNL

    2010-05-01

    Hydrokinetic energy technologies have been proposed as renewable, environmentally preferable alternatives to fossil fuels for generation of electricity. Hydrokinetic technologies harness the energy of water in motion, either from waves, tides or from river currents. For energy capture from free-flowing rivers, arrays of rotating devices are most commonly proposed. The placement of hydrokinetic devices in large rivers is expected to increase the underwater structural complexity of river landscapes. Moore and Gregory (1988) found that structural complexity increased local fish populations because fish and other aquatic biota are attracted to structural complexity that provides microhabitats with steep flow velocity gradients (Liao 2007). However, hydrokinetic devices have mechanical parts, blades, wings or bars that move through the water column, posing a potential strike or collision risk to fish and other aquatic biota. Furthermore, in a setting with arrays of hydrokinetic turbines the cumulative effects of multiple encounters may increase the risk of strike. Submerged structures associated with a hydrokinetic (HK) project present a collision risk to aquatic organisms and diving birds (Cada et al. 2007). Collision is physical contact between a device or its pressure field and an organism that may result in an injury to that organism (Wilson et al. 2007). Collisions can occur between animals and fixed submerged structures, mooring equipment, horizontal or vertical axis turbine rotors, and structures that, by their individual design or in combination, may form traps. This report defines strike as a special case of collision where a moving part, such as a rotor blade of a HK turbine intercepts the path of an organism of interest, resulting in physical contact with the organism. The severity of a strike incidence may range from minor physical contact with no adverse effects to the organism to severe strike resulting in injury or death of the organism. Harmful effects

  10. Nitrogen Mineralization from Animal Manures and Its Relation to Organic N Fractions

    Institute of Scientific and Technical Information of China (English)

    LI Ling-ling; LI Shu-tian

    2014-01-01

    Laboratory aerobic incubation was conducted for 161 d to study N mineralization and the changes of organic N fractions of nine different manures (3 chicken manures, 3 pig manures and 3 cattle manures) from different farms/locations. Results indicated that signiifcant (P<0.01 orP<0.001) difference existed in N mineralization between manures. The rapid N mineralization in manures occurred during 56 to 84 d of incubation. First order exponential model can be used to describe N mineralization from chicken manures and pig manures, while quadratic equation can predict mineralization of organic N from cattle manures. An average of 21, 19 and 13% added organic N from chicken manure, pig manure and cattle manure was mineralized during 161 d of incubation. Amino acid-N was the main source of N mineralization. The changes of amino acid-N together with ammonium N could explain signiifcantly 97 and 96% of the variation in mineralized N from manured soils and manures. Amino acid-N and ammonium N are two main N fractions in determining N mineralization potential from manures. Amino acid-N contributed more to the mineralized N than ammonium N.

  11. Strategies for Transferring Mixtures of Organic Contaminants from Aquatic Environments into Bioassays

    DEFF Research Database (Denmark)

    Jahnke, Annika; Mayer, Philipp; Schäfer, Sabine;

    2016-01-01

    Mixtures of organic contaminants are ubiquitous in the environment. Depending on their persistence and physicochemical properties, individual chemicals that make up the mixture partition and distribute within the environment and might then jointly elicit toxicological effects. For the assessment...... and monitoring of such mixtures, a variety of cell-based in vitro and low-complexity in vivo bioassays based on algae, daphnids or fish embryos are available. A very important and sometimes unrecognized challenge is how to combine sampling, extraction and dosing to transfer the mixtures from the...... environment into bioassays, while conserving (or re-establishing) their chemical composition at adjustable levels for concentration-effect assessment. This article outlines various strategies for quantifiable transfer from environmental samples including water, sediment, and biota into bioassays using total...

  12. Phototransformation of Amlodipine in Aqueous Solution: Toxicity of the Drug and Its Photoproduct on Aquatic Organisms

    Directory of Open Access Journals (Sweden)

    Marina DellaGreca

    2007-01-01

    Full Text Available The phototransformation of amlodipine in water was investigated under various conditions. A quantum yield ΦS2.2×10−4 and a half-life time t1/2 0.419 days were calculated when the drug in water (10−4 M was exposed to sunlight. The only photoproduct found was its pyridine derivative. Formation of this product was explained on the basis of a radical cation intermediate. The acute and chronic toxicity of the drug and its photoproduct were evaluated on different organisms of the freshwater chain (Brachionus calyciflorus, Thamnocephalus platyurus, Daphnia magna, Ceriodaphnia dubia. The photoproduct exhibited a stronger toxic potential than the parent drug on the long time for C. dubia.

  13. Strategies for Transferring Mixtures of Organic Contaminants from Aquatic Environments into Bioassays.

    Science.gov (United States)

    Jahnke, Annika; Mayer, Philipp; Schäfer, Sabine; Witt, Gesine; Haase, Nora; Escher, Beate I

    2016-06-01

    Mixtures of organic contaminants are ubiquitous in the environment. Depending on their persistence and physicochemical properties, individual chemicals that make up the mixture partition and distribute within the environment and might then jointly elicit toxicological effects. For the assessment and monitoring of such mixtures, a variety of cell-based in vitro and low-complexity in vivo bioassays based on algae, daphnids or fish embryos are available. A very important and sometimes unrecognized challenge is how to combine sampling, extraction and dosing to transfer the mixtures from the environment into bioassays, while conserving (or re-establishing) their chemical composition at adjustable levels for concentration-effect assessment. This article outlines various strategies for quantifiable transfer from environmental samples including water, sediment, and biota into bioassays using total extraction or polymer-based passive sampling combined with either solvent spiking or passive dosing. PMID:26804122

  14. Body composition in aquatic organisms — A global data bank of relationships between mass, elemental composition and energy content

    Science.gov (United States)

    Brey, Thomas; Müller-Wiegmann, Corinna; Zittier, Zora M. C.; Hagen, Wilhelm

    2010-10-01

    We introduce a global data bank on body composition of aquatic organisms that is available at http://www.thomas-brey.de/science/virtualhandbook. It covers ratios between body mass (wet, dry, ash free dry mass), body composition (protein, lipid, carbohydrate), macro-elements (C, N, P) and energy content (J). Sofar, data for 3158 different taxa (animals, plants, bacteria) were collected from 725 different sources. The principal purpose of the data bank is mining for conversion factors, as necessary in ecological studies that require a common energetic currency. The data bank can be used to explore general ecological principles, too: among all animals, carnivorous swimmers have the highest energy density, presumably an across-taxon selection for propulsion power and handling force. Plants and animals do not only differ in their C/N and C/P ratios, but these ratios change with temperature in opposite directions. In plants, C/N and C/P increase with temperature, most likely a response to the higher levels of N and P in polar waters. In animals C/N and C/P decrease with temperature, an indicator for selection towards lower activity and larger lipid stores in polar animals.

  15. ASE extraction method for simultaneous carbon and nitrogen stable isotope analysis in soft tissues of aquatic organisms

    Energy Technology Data Exchange (ETDEWEB)

    Bodin, Nathalie [ISM/LPTC, UMR 5255 CNRS, Universite de Bordeaux 1, 351 Cours de la Liberation, 33405 Talence (France); CRH, UMR 212 EME, Institut de Recherche et de Developpement, Av Jean Monnet BP171, 34203 Sete (France); Budzinski, Helene, E-mail: h.budzinski@ism.u-bordeaux1.fr [ISM/LPTC, UMR 5255 CNRS, Universite de Bordeaux 1, 351 Cours de la Liberation, 33405 Talence (France); Le Menach, Karyn; Tapie, Nathalie [ISM/LPTC, UMR 5255 CNRS, Universite de Bordeaux 1, 351 Cours de la Liberation, 33405 Talence (France)

    2009-06-08

    Since lipids are depleted in {sup 13}C relative to proteins and carbohydrates, variations in lipid composition among species and within individuals significantly influence {delta}{sup 13}C and may result in misleading ecological interpretations. Whereas lipid extraction before IRMS analysis constitutes a way of stable isotope result lipid-normalisation, such a procedure was given up because of the un-controlled effects of the methods used (i.e., 'Bligh and Dyer', Soxhlet, etc.) on {delta}{sup 15}N. The aim of this work was to develop a simple, rapid and efficient lipid extraction method allowing for simultaneous C and N stable isotope analysis in the biological soft tissues of aquatic organisms. The goal was to be free from the lipid influence on {delta}{sup 13}C values without interfering with {delta}{sup 15}N values. For that purpose, the modern automated pressurized liquid extraction technique ASE (accelerated solvent extraction) was selected. Eel muscles representative of a broad range of fat contents were extracted via ASE by using different semi-polar solvents (100% dichloromethane and 80% n-hexane/20% acetone) and by operating at different temperature (ambient temperature and 100 deg. C) and pressure (750 and 1900 psi) conditions. The results were discussed in terms of lipid extraction efficiency as well as {delta}{sup 13}C and {delta}{sup 15}N variability.

  16. Efficacy of Two Larvasonic™ Units Against Culex Larvae and Effects on Common Aquatic Nontarget Organisms in Harris County, Texas.

    Science.gov (United States)

    Fredregill, Chris L; Motl, Greg C; Dennett, James A; Bueno, Rudy; Debboun, Mustapha

    2015-12-01

    The Larvasonic™ Field Arm Mobile Wetlands Unit and SD-Mini were tested for efficacy against Culex larvae, and effects on aquatic nontarget organisms (NTO). The Field Arm provided 84.61% to 100% control of caged Culex larvae out to 0.91-m distance in shallow ditches and 60.45% control of Culex larvae at 0.61-m without any effects to caged NTO. Slow ditch treatment achieved 77.35% control compared to fast treatment (20.42%), whereas 77.65% control was obtained along edges of a neglected swimming pool, compared to near the middle (23.97%). In bucket tests, the SD-Mini provided >97% control of Culex and 85.35% reduction of immature giant water bugs, which decreased slightly (83.45%) over the monitoring period, which was not significantly different from cannibalistic damselflies (62.80%), with reduction of both being significantly higher than other NTO tested. There was a small (0.37%) reduction of dragonflies (naiads), due to cannibalism. Both Larvasonic units could effectively augment conventional larvicide operations in smaller areas without causing resistance within mosquito populations or harming NTO when used properly. PMID:26675460

  17. Dynamic of the active fraction of organic matter in some meadow soils

    Directory of Open Access Journals (Sweden)

    Mahtali Sbih

    2012-01-01

    Full Text Available The microbial biomass (MB and light fraction (LF of organic matter are often considered as active fraction of organic matter (AFOM and as indices of soil fertility and microbial activity. This study was performed in order to assess the turnover of AFOM using long-term incubation (56 weeks at25 °Cin 34 meadow soils with different physical and chemical properties such as soil texture, organic C and total N. The MB and LF were determined at 8 and 5 times during the incubation period using fumigation-extraction technique for MB and densimetric method for LF. The amount of MB-C and MB-N mineralized increased with time of incubation. At the beginning of incubation, the C and N content of soil MB represented respectively 0.76 to 3.7% of total organic C and 1.94 to 10.7% of total N. The C and N content of LF represented respectively 2.9 to 25.6% of total organic C and 1.7 to 17.5% of total N. At the end of incubation, the losses of MB-C and MB-N from soils reached respectively 71 and 82% of the initial amounts. The MB and LF dynamic were well described by a two-component first-order rate model. The amount of N in the labile MB and LF pools represented respectively 54% of total MB-N and 61% of total LF-N. The more stable MB and LF pools had higher half-life than labile pools. The results obtained indicated that the stable LF would be the precursor of soil humic compounds.

  18. Insights into the secondary fraction of the organic aerosol in a Mediterranean urban area: Marseille

    Directory of Open Access Journals (Sweden)

    I. El Haddad

    2010-11-01

    Full Text Available A comprehensive aerosol characterization was conducted at Marseille during summer, including organic (OC and elemental carbon (EC, major ionic species, radiocarbon (14C, water soluble OC and HULIS (HUmic LIke Substances, elemental composition and primary and secondary organic markers. This paper is the second paper of a two-part series investigating the sources of organic aerosol. While the first paper investigates the primary sources of Organic Aerosol (OA (El Haddad et al., 2010, this second paper focused on the secondary fraction of OA.

    In the context of overall OC mass balance, primary OC (POC contributes on average for only 22% and was dominated by vehicular emissions accounting on average for 17% of OC. As a result, 78% of OC mass cannot be attributed to the major primary sources and remains un-apportioned. Radiocarbon measurements suggest that more than 70% of this fraction is of modern origins, assigned predominantly to biogenic secondary organic carbon (BSOC. Therefore, contributions from three traditional BSOC precursors, isoprene, α-pinene and β-caryophellene, were considered. These were estimated using the ambient concentrations of SOA markers from each precursor and laboratory-derived marker mass fraction factors.

    Secondary organic markers derived from isoprene photo-oxidation (i.e. 2-methylglyceric acid and 2-methyltetrols do not exhibit the same temporal trends. This variability was assigned to the influence of NOx concentration on their formation pathways and to their potential decay by further processing in the atmosphere. The influence of changes in isoprene chemistry on assessment of isoprene SOC contribution was evaluated explicitly. The results suggest a 60-fold variation between the different estimates computed using different isoprene SOC markers, implying that the available profiles do not reflect the actual isoprene SOC composition observed in Marseille.

    Using the marker

  19. Chemical attributes, total organic carbon stock and humified fractions of organic matter soil submitted to different systems of sugarcane management

    Directory of Open Access Journals (Sweden)

    Jean Sérgio Rosset

    2014-10-01

    Full Text Available Mechanized harvesting maintenance of trash from cane sugar and soil application of waste as vinasse and filter cake can improve the system of crop yield. Thus, this study aimed to evaluate the changes in the chemical, the stock of total organic carbon and humified organic matter fractions in an Oxisol cultivated with cane sugar with the following management systems: with sugarcane vinasse application (CCV, without application of burnt cane waste (CQS, with burnt cane vinasse application (CQV, with application of burnt cane filter cake (CQTF and burnt cane with joint application of vinasse and filter cake (CQVTF. For reference we used an area of natural vegetation (NV, Cerrado sensu stricto. Treatment CQVTF showed improvement in soil chemical properties, increased inventory levels of total organic carbon – TOC (values ranging from 21.28 to 40.02 Mg ha-1 and humified fractions of soil organic matter in relation to other treatments. The CQS area at a depth of 0-0.05 m, showed the greatest losses of soil TOC stocks (56.3% compared to NV. The adoption of management presented CCV and chemical attributes of the soil TOC stocks equivalent to those observed in areas with CQV CQTF and despite the short period of adoption (3 years. The TOC correlated with the sum of bases (r = 0.76 **, cation exchange capacity (r = 0.59 ** and base saturation (r = 0.63 **, while the humic acids (r = 0.40 ** fulvic acids (r = 0.49 ** and humin (r = 0.59 ** correlated with the cation exchange capacity of the soil. These results indicate that the preservation of trash in the management of cane sugar added to the application of vinasse and filter cake increases the TOC stocks promoting improvement in soil chemical properties.

  20. Impact of contaminants on aquatic systems and inundated sites with respect to flood events - In vitro biotests, chemical target analysis and fractionation methods

    OpenAIRE

    Wölz, Jan

    2009-01-01

    Scope of the present study is the development and application of aquatic in vitro bioassays and methods of effect-directed analysis (EDA). It aims at investigating contamination of suspended particulate matter (SPM) and pollution of inundated sites and riparian aquifer, respectively. In the first part of this study, SPM was sampled during flood events and toxicological activities were determined. The second part of the study dealt with possible conflict of interests between flood management (...

  1. Static and dynamic removal of aquatic natural organic matter by carbon nanotubes.

    Science.gov (United States)

    Ajmani, Gaurav S; Cho, Hyun-Hee; Abbott Chalew, Talia E; Schwab, Kellogg J; Jacangelo, Joseph G; Huang, Haiou

    2014-08-01

    Carbon nanotubes (CNTs) were investigated for their capability and mechanisms to simultaneously remove colloidal natural organic matter (NOM) and humic substances from natural surface water. Static removal testing was conducted via adsorption experiments while dynamic removal was evaluated by layering CNTs onto substrate membranes and filtering natural water through the CNT-layered membranes. Analyses of treated water samples showed that removal of humic substances occurred via adsorption under both static and dynamic conditions. Removal of colloidal NOM occurred at a moderate level of 36-66% in static conditions, independent of the specific surface area (SSA) of CNTs. Dynamic removal of colloidal NOM increased from approximately 15% with the unmodified membrane to 80-100% with the CNT-modified membranes. Depth filtration played an important role in colloidal NOM removal. A comparison of the static and dynamic removal of humic substances showed that equilibrium static removal was higher than dynamic (p filtration, it appeared that CNT mat structure was an important determinant of removal efficiencies for colloidal NOM and humic substances during CNT membrane filtration.

  2. ORGANIC MATTER AND HUMIC FRACTIONS OF A HAPLIC ACRISOL AS AFFECTED BY COMPOSTED PIG SLURRY

    Directory of Open Access Journals (Sweden)

    Ana Cristina Lüdtke

    2016-01-01

    Full Text Available The goal of this study was to investigate the effect of composted pig slurry (PS on the organic matter concentration and distribution of humic acid (HA, fulvic acid (FA and humin (HU fractions. The fractions were quantified following the addition of composted PS to the soil, which was produced with no acidification (T2 or with acidification with H3PO4 (T3; and in soil without compost addition (T1. The HA chemical composition was analyzed by FTIR spectroscopy. The addition of the two composts did not change the soil carbon concentration but affected the distribution of the humic fractions. For the three treatments, the carbon concentration of humic substances increased until 52 days following compost addition, with more pronounced increases with the addition of non-acidified PS compost (14.5 g kg-1 and acidified PS compost (15.1 g kg-1. This increase was reflected in both the FA and HA concentrations. The addition of compost with PS acidification resulted in the formation of larger humic micelles (HA with higher aromatic content and fewer functional groups than the non-acidified PS compost. These findings, together with a lower proportion of carbohydrate-type structures, indicated the presence of more stable humic micelles in the soil treated with acidified PS compost.

  3. Aquatic plants

    DEFF Research Database (Denmark)

    Madsen, T. V.; Sand-Jensen, K.

    2006-01-01

    Aquatic fl owering plants form a relatively young plant group on an evolutionary timescale. The group has developed over the past 80 million years from terrestrial fl owering plants that re-colonised the aquatic environment after 60-100 million years on land. The exchange of species between...... terrestrial and aquatic environments continues today and is very intensive along stream banks. In this chapter we describe the physical and chemical barriers to the exchange of plants between land and water....

  4. Fractionation of Rare Earth Elements in Plants Ⅰ. Fractionation Patterns and Their Forming Mechanisms in Different Organs of Triticum Aestivum

    Institute of Scientific and Technical Information of China (English)

    Liang Tao; Ding Shiming; Zhang Chaosheng; Zhang Zili; Yan Juncai; Li Haitao

    2005-01-01

    Fractionations of rare earth elements (REEs) and the forming mechanisms in plants were studied using Triticum aestivum as plant material with application of exogenous REEs and hydroponic culture. REEs were significantly fractionated in different parts of Triticum aestivum. M-type tetrad effect could be observed in both root and shoot of Triticum aestivum, which might result from the different abilities of REEs to form phosphate precipitation. Middle REEs (MREEs), light REEs (LREEs) and heavy REEs (HREEs) were enriched in root, stem and leaf of Triticum aestivum, respectively. REE speciation calculations using VMINTEQ program show REEs in simulated xylem solution mainly exist as REE-EDTA- and RE3+, but only HREEs are enriched in REE-EDTA-, while LREEs are enriched in the other REE species. It is suggested that the fractionation between LREEs and HREEs might be caused by the uptake of REE-EDTA- in Triticum aestivum leaves, but might result from the uptake of the other REE species in their stems.

  5. Fractionation of Added Cadmium in Submerged Soils as Affected by Organic Materials

    Institute of Scientific and Technical Information of China (English)

    WANGGUO; GAOSHAN; 等

    1999-01-01

    The effect of three organic materials(rice straw,Chinese milk vetch and pig manure)on the fractionation of cadmium added into two soils(a red soil and a fluvo-aquic soil) was studied using submerged incubation experiment.The organic materials increased soil soild organic carbon(SOC),pH value,the concentration of active Si in all the treatments and active Fe and Mn in some treatments.Accumulated SOC caused directly the increase of Cd bound to solid organic matter and consequently the decrease of exchangeable Cd.Higher active Si and pH,as well as lower Eh,were also responsible for the reduction of exchangeable Cd.Cd bound to mn oxide was positively correlated with pH values and rose significantly after one-month incubation,but decreased after three-month incubation.Cd bound to amporphous Fe oxide increased with the incubation time,but was not affected significantly by adding organic materials.

  6. The Potential Impacts of OTEC Intakes on Aquatic Organisms at an OTEC Site under Development on Kauai, HI

    Energy Technology Data Exchange (ETDEWEB)

    Oney, Stephen K. [OTE Corporation; Hogan, Timothy [Alden Research Laboratory; Steinbeck, John [Tenera Environmental

    2013-08-31

    Ocean thermal energy conversion (OTEC) is a marine renewable energy technology with the potential to contribute significantly to the baseload power needs of tropical island communities and remote U.S. military installations. As with other renewable energy technologies, however, there are potential challenges to its commercialization: technological, financial, social, and environmental. Given the large volumes of seawater required to drive the electricity-producing cycle, there is potential for the intakes to negatively impact the marine resources of the source waterbody through the impingement and entrainment of marine organisms. The goal of this project was to identify feasible warm water intake designs for a land-based OTEC facility proposed for development in Port Allen, Kauai and to characterize the populations of ichthyoplankton near the proposed warm water intake location that could be at risk of entrainment. The specific objectives of this project were to: • Complete a site-specific assessment of available and feasible warm water intake technologies to determine the best intake designs for minimizing impacts to aquatic organisms at the proposed land-based OTEC site in Port Allen, Kauai. • Complete a field sampling program to collect biological data to characterize the baseline populations of ichthyoplankton near the sites being considered for the warm water intake at the proposed land-based OTEC site in Port Allen, Kauai. Various intake design options are presented with the focus on providing adequate environmental protection to the local ichthyoplankton population while providing an economically viable intake option to the OTEC developer. Further definition by NOAA and other environmental regulators is required to further refine the designs presented to meet all US regulations for future OTEC development.

  7. Storage and turnover of organic matter fractions along a Siberian Arctic soil transect

    Science.gov (United States)

    Gentsch, Norman; Mikutta, Robert; Shibistova, Olga; Guggenberger, Georg

    2013-04-01

    Recent observation and climate models demonstrate that arctic ecosystems are already affected by climate warming, as revealed by continuous permafrost degradation and increase of active layer depths. Variations of organic matter (OM) storage in different soil horizons and the OM quality are likely the major drivers of trace gas emissions to the atmosphere. A better understanding of the biogeochemical cycling of OM in permafrost environments is the key to predict future climate changes and the role of terrestrial arctic regions. This study investigates the storage and turnover patterns of OM in functionally different pools, i.e., in particulate plant debris, extractable-water-soluble OM, and mineral-associated OM in permafrost soils along a West-East Siberian transect in the Russian Arctic. We quantified the stocks of total soil organic C (OC) and the respective OM fractions for the first soil meter. Furthermore, we estimated their apparent 14C ages by accelerator mass spectrometry, and determined the mineralization rates and bioavailability of particulate, mineral-bound, and bulk OM in a 90-day incubation experiment. Particulate OM was separated from the mineral-associated OM fraction by density fractionation with sodium polytungstate (density cut-off 1.6 g cm-3) and the OM liberated by this treatment was quantified. Considerable differences in OM storage existed from the West- to the East Siberian Arctic. Cryosols of the Central- and East Siberian sampling sites stored on average 56% more OC than those in West Siberia (25 ± 7 kg m-2versus 11 ± 4 kg m-2 to 1 m soil depth). However, the proportion of the three OM fractions to total OM was similar among the sites. In mineral soil horizons, on average, 17 ± 5% of the total OM was particulate OM, 61 ± 10% was associated with minerals, and 21 ± 3% could be mobilized in dissolved forms during density fractionation. Except for West Siberian soils, ~30% of the OM of the first soil meter was stored in permafrost while

  8. Toxic effect of a marine bacterium on aquatic organisms and its algicidal substances against Phaeocystis globosa.

    Science.gov (United States)

    Yang, Qiuchan; Chen, Lina; Hu, Xiaoli; Zhao, Ling; Yin, Pinghe; Li, Qiang

    2015-01-01

    Harmful algal blooms have caused enormous damage to the marine ecosystem and the coastal economy in China. In this paper, a bacterial strain B1, which had strong algicidal activity against Phaeocystis globosa, was isolated from the coastal waters of Zhuhai in China. The strain B1 was identified as Bacillus sp. on the basis of 16S rDNA gene sequence and morphological characteristics. To evaluate the ecological safety of the algicidal substances produced by strain B1, their toxic effects on marine organisms were tested. Results showed that there were no adverse effects observed in the growth of Chlorella vulgaris, Chaetoceros muelleri, and Isochrystis galbana after exposure to the algicidal substances at a concentration of 1.0% (v/v) for 96 h. The 48h LC50 values for Brachionus plicatilis, Moina mongolica Daday and Paralichthys olivaceus were 5.7, 9.0 and 12.1% (v/v), respectively. Subsequently, the algicidal substances from strain B1 culture were isolated and purified by silica gel column, Sephadex G-15 column and high-performance liquid chromatography. Based on quadrupole time-of-flight mass spectrometry and PeakView Software, the purified substances were identified as prolyl-methionine and hypoxanthine. Algicidal mechanism indicated that prolyl-methionine and hypoxanthine inhibited the growth of P. globosa by disrupting the antioxidant systems. In the acute toxicity assessment using M. mongolica, 24h LC50 values of prolyl-methionine and hypoxanthine were 7.0 and 13.8 g/L, respectively. The active substances produced by strain B1 can be considered as ecologically and environmentally biological agents for controlling harmful algal blooms. PMID:25646807

  9. Toxic effect of a marine bacterium on aquatic organisms and its algicidal substances against Phaeocystis globosa.

    Directory of Open Access Journals (Sweden)

    Qiuchan Yang

    Full Text Available Harmful algal blooms have caused enormous damage to the marine ecosystem and the coastal economy in China. In this paper, a bacterial strain B1, which had strong algicidal activity against Phaeocystis globosa, was isolated from the coastal waters of Zhuhai in China. The strain B1 was identified as Bacillus sp. on the basis of 16S rDNA gene sequence and morphological characteristics. To evaluate the ecological safety of the algicidal substances produced by strain B1, their toxic effects on marine organisms were tested. Results showed that there were no adverse effects observed in the growth of Chlorella vulgaris, Chaetoceros muelleri, and Isochrystis galbana after exposure to the algicidal substances at a concentration of 1.0% (v/v for 96 h. The 48h LC50 values for Brachionus plicatilis, Moina mongolica Daday and Paralichthys olivaceus were 5.7, 9.0 and 12.1% (v/v, respectively. Subsequently, the algicidal substances from strain B1 culture were isolated and purified by silica gel column, Sephadex G-15 column and high-performance liquid chromatography. Based on quadrupole time-of-flight mass spectrometry and PeakView Software, the purified substances were identified as prolyl-methionine and hypoxanthine. Algicidal mechanism indicated that prolyl-methionine and hypoxanthine inhibited the growth of P. globosa by disrupting the antioxidant systems. In the acute toxicity assessment using M. mongolica, 24h LC50 values of prolyl-methionine and hypoxanthine were 7.0 and 13.8 g/L, respectively. The active substances produced by strain B1 can be considered as ecologically and environmentally biological agents for controlling harmful algal blooms.

  10. Trace element accumulation and trophic relationships in aquatic organisms of the Sundarbans mangrove ecosystem (Bangladesh).

    Science.gov (United States)

    Borrell, Asunción; Tornero, Victoria; Bhattacharjee, Dola; Aguilar, Alex

    2016-03-01

    The Sundarbans forest is the largest and one of the most diverse and productive mangrove ecosystems in the world. Located at the northern shoreline of the Bay of Bengal in the Indian Ocean and straddling India and Bangladesh, the mangrove forest is the result of three primary river systems that originate further north and northwest. During recent decades, the Sundarbans have been subject to increasing pollution by trace elements caused by the progressive industrialization and urbanization of the basins of these three rivers. As a consequence, animals and plants dwelling downstream in the mangroves are exposed to these pollutants in varying degrees, and may potentially affect human health when consumed. The aim of the present study was to analyse the concentrations of seven trace elements (Zn, Cu, Cr, Hg, Pb, Cd and As) in 14 different animal and plant species collected in the Sundarbans in Bangladesh to study their transfer through the food web and to determine whether their levels in edible species are acceptable for human consumption. δ(15)N values were used as a proxy of the trophic level. A decrease in Zn, Cu, Pb and Cd levels was observed with increasing trophic position. Trace element concentrations measured in all organisms were, in general, lower than the concentrations obtained in other field studies conducted in the same region. When examined with respect to accepted international standards, the concentrations observed in fish and crustaceans were generally found to be safe for human consumption. However, the levels of Zn in Scylla serrata and Cr and Cd in Harpadon nehereus exceeded the proposed health advisory levels and may be of concern for human health. PMID:26748006

  11. Multispecies QSAR modeling for predicting the aquatic toxicity of diverse organic chemicals for regulatory toxicology.

    Science.gov (United States)

    Singh, Kunwar P; Gupta, Shikha; Kumar, Anuj; Mohan, Dinesh

    2014-05-19

    The research aims to develop multispecies quantitative structure-activity relationships (QSARs) modeling tools capable of predicting the acute toxicity of diverse chemicals in various Organization for Economic Co-operation and Development (OECD) recommended test species of different trophic levels for regulatory toxicology. Accordingly, the ensemble learning (EL) approach based classification and regression QSAR models, such as decision treeboost (DTB) and decision tree forest (DTF) implementing stochastic gradient boosting and bagging algorithms were developed using the algae (P. subcapitata) experimental toxicity data for chemicals. The EL-QSAR models were successfully applied to predict toxicities of wide groups of chemicals in other test species including algae (S. obliguue), daphnia, fish, and bacteria. Structural diversity of the selected chemicals and those of the end-point toxicity data of five different test species were tested using the Tanimoto similarity index and Kruskal-Wallis (K-W) statistics. Predictive and generalization abilities of the constructed QSAR models were compared using statistical parameters. The developed QSAR models (DTB and DTF) yielded a considerably high classification accuracy in complete data of model building (algae) species (97.82%, 99.01%) and ranged between 92.50%-94.26% and 92.14%-94.12% in four test species, respectively, whereas regression QSAR models (DTB and DTF) rendered high correlation (R(2)) between the measured and model predicted toxicity end-point values and low mean-squared error in model building (algae) species (0.918, 0.15; 0.905, 0.21) and ranged between 0.575 and 0.672, 0.18-0.51 and 0.605-0.689 and 0.20-0.45 in four different test species. The developed QSAR models exhibited good predictive and generalization abilities in different test species of varied trophic levels and can be used for predicting the toxicities of new chemicals for screening and prioritization of chemicals for regulation.

  12. Chemical Hydrolysis and Thermophilic Anaerobic Digestion of Organic Fraction of Municipal Solid Waste

    Directory of Open Access Journals (Sweden)

    Yosvany Díaz Domínguez

    2014-03-01

    Full Text Available The hydrolysis of the macromolecules that compose the organic fraction of municipal solid waste canbe taken for chemical, physical and biological methods, having all as aim the unfolding of the complexmolecules in simplier monomer. Thereby the degradation of organic matter is enhanced and resultsmore efficient the process of biogas via anaerobic. Chemical pretreatments were employed in the workusing sodium hydroxide (NaOH and hydrogen peroxide (H2O2 as reagents.The soluble chemicaloxygen demand (COD, the maximum methane yield and the methane rates production were used toevaluate the pretreatment actions. The degradation of the waste was able to be increased by allowinga comparative analysis to determine the best working conditions for this stage and subsequently itsimpact in the generation of biogas, methane specifically.

  13. Characteristics of the organic fraction of municipal solid waste and methane production: A review.

    Science.gov (United States)

    Campuzano, Rosalinda; González-Martínez, Simón

    2016-08-01

    Anaerobic digestion of the organic fraction of municipal solid waste (OFMSW) is a viable alternative for waste stabilization and energy recovery. Biogas production mainly depends on the type and amount of organic macromolecules. Based on results from different authors analysing OFMSW from different cities, this paper presents the importance of knowing the OFMSW composition to understand how anaerobic digestion can be used to produce methane. This analysis describes and discusses physical, chemical and bromatological characteristics of OFMSW reported by several authors from different countries and cities and their relationship to methane production. The main conclusion is that the differences are country and not city dependant. Cultural habits and OFMSW management systems do not allow a generalisation but the individual analysis for specific cities allow understanding the general characteristics for a better methane production. Not only are the OFMSW characteristics important but also the conditions under which the methane production tests were performed.

  14. Characteristics of the organic fraction of municipal solid waste and methane production: A review.

    Science.gov (United States)

    Campuzano, Rosalinda; González-Martínez, Simón

    2016-08-01

    Anaerobic digestion of the organic fraction of municipal solid waste (OFMSW) is a viable alternative for waste stabilization and energy recovery. Biogas production mainly depends on the type and amount of organic macromolecules. Based on results from different authors analysing OFMSW from different cities, this paper presents the importance of knowing the OFMSW composition to understand how anaerobic digestion can be used to produce methane. This analysis describes and discusses physical, chemical and bromatological characteristics of OFMSW reported by several authors from different countries and cities and their relationship to methane production. The main conclusion is that the differences are country and not city dependant. Cultural habits and OFMSW management systems do not allow a generalisation but the individual analysis for specific cities allow understanding the general characteristics for a better methane production. Not only are the OFMSW characteristics important but also the conditions under which the methane production tests were performed. PMID:27236403

  15. Organic fraction of solid waste in biodigester; Fracao organica de lixo urbano como substrato para biodigestor

    Energy Technology Data Exchange (ETDEWEB)

    Gorgati, Claudia Q. [UNESP, Botucatu, SP (Brazil). Faculdade de Ciencias Agronomicas. Curso de Pos-graduacao em Energia na Agricultura; Lucas Junior, Jorge de [UNESP, Jaboticabal, SP (Brazil). Faculdade de Ciencias Agrarias e Veterinarias. Dept. de Engenharia Rural

    1999-12-01

    The study of the anaerobic digestion was accomplished with the organic fraction of urban solid waste collected at the composting plant - CONSTRUFERT- from the municipal district of Sao Jose do Rio Preto - SP. The essay was conducted in six bio digesters at the Rural Engineering Department of the Faculdade de Ciencias Agrarias e Veterinarias, in Jaboticabal/SP, three of them with fresh urban organic waste and remaining ones with dried and ground material. With regard to the anaerobic digestion the biogas production was monitored and the data indicated the energetic potential of urban waste, which was found to be 0.1034 - 0.1395 m{sup 3}/Kg of raw urban waste with reduction of volatile solids between 56 and 66.50%. (author)

  16. Comparative Toxicity of Combined Particle and Semi-Volatile Organic Fractions of Gasoline and Diesel Emissions

    Energy Technology Data Exchange (ETDEWEB)

    Mauderly, Joe; Seagrave, JeanClare; McDonald, Jacob; Gigliotti,Andrew; Nikula, Kristen; Seilkop, Steven; Gurevich, Michael

    2002-08-25

    Little is known about the relative health hazards presented by emissions from in-use gasoline and diesel engines. Adverse health effects have been ascribed to engine emissions on the basis of: (1) the presence of known toxic agents in emissions; (2) high-dose animal and bacterial mutagenicity tests; and (3) studies indicating gradients of health effects with proximity to roadways. Most attention has been given to the particulate fraction of emissions; little attention has been given to the semi-volatile organic fraction. However, the semi-volatile fraction overlaps the particulate fraction in composition and is always present in the vicinity of fresh emissions. Although the potential health effects of diesel emissions have been frequently studied and debated during the past 20 years (EPA, 2002), relatively little attention has been given to the toxicity of emissions from gasoline engines. In view of the considerable progress in cleaning up diesel emissions, it would be useful to compare the toxicity of emissions from contemporary on-road diesel technology with that of emissions from the in-use gasoline fleet that is well-accepted by the public. It would also be useful to have a set of validated tests for rapid, cost-effective comparisons of the toxicity of emission samples, both for comparisons among competing technologies (e.g., diesel, gasoline, natural gas) and for determining the impacts of new fuel, engine, and after-treatment strategies on toxicity. The Office of Heavy Vehicle Technologies has sponsored research aimed at developing and applying rapid-response toxicity tests for collected emission samples (Seagrave et al., 2000). This report presents selected results from that work, which is being published in much greater detail in the peer-reviewed literature (Seagrave et al., 2002).

  17. Pig slurry and mineral fertilization strategies' effects on soil quality: macroaggregate stability and organic matter fractions.

    Science.gov (United States)

    Yagüe, María R; Bosch-Serra, Àngela D; Antúnez, Montserrat; Boixadera, Jaume

    2012-11-01

    Applying pig slurry to the land as fertilizer at appropriate agronomic rates is important to close nutrient cycles and optimize the value of organic matter. However a long-term discussion has taken place about its effects on soil quality. In the north-east of Spain, eight fertilization strategies were evaluated on the soil quality parameters' aggregate stability, soil organic matter (SOM) physical fractions and soil microbial biomass (SMB). Six strategies used different pig slurries (PS) which provided organic matter from 1.7 to 2.6 t ha(-1)yr(-1), the rest (mineral N fertilization and a control) did not. Pig slurries were applied at sowing and/or at cereal tillering, as sidedressing. Field experiments were maintained for an 8-year period, in a silty loam soil devoted to a rainfed winter cereal. Soil samples were taken once, before the last sidedressing in 2011. Aggregate stability was quantified using the standard water-stable aggregate method but including a modification which meant that pre-wetting was avoided (WSA(MOD)). When using the WSA(MOD) method, we found a tendency for the percentage of water-stable aggregates to increase due to PS application (differences of up to 74% in the increment) and it was more marked the nearer they were measured to the application time (3 months vs. 12 months). The strategies which include PS show a positive effect on the SOM amount, mainly in the 0.05-0.2 mm light fraction, which increased by up to 34% with every 10 t ha(-1) organic C applied, and on SMB (up to 53% increment). There is a positive and significant linear relationship (p fertilization strategies improves soil quality parameters. However, the soil quality benefits need to be balanced with any other potential environmental impact.

  18. Energy recovery from organic fractions of municipal solid waste: A case study of Hyderabad city, Pakistan.

    Science.gov (United States)

    Safar, Korai M; Bux, Mahar R; Aslam, Uqaili M; Ahmed, Memon S; Ahmed, Lashari I

    2016-04-01

    Non-renewable energy sources have remained the choice of the world for centuries. Rapid growth in population and industrialisation have caused their shortage and environmental degradation by using them. Thus, at the present rate of consumption, they will not last very long. In this prospective, this study has been conducted. The estimation of energy in terms of biogas and heat from various organic fractions of municipal solid waste is presented and discussed. The results show that organic fractions of municipal solid waste possess methane potential in the range of 3%-22% and their heat capacity ranges from 3007 to 20,099 kJ kg(-1) Also, theoretical biogas potential of different individual fruit as well as vegetable components and mixed food waste are analysed and estimated in the range of 608-1244 m(3) t(-1) Further, the share of bioenergy from municipal solid waste in the total primary energy supply in Pakistan has been estimated to be 1.82%. About 8.43% of present energy demand of the country could be met from municipal solid waste. The study leads us to the conclusion that the share of imported energy (i.e. 0.1% of total energy supply) and reduction in the amount of energy from fossil fuels can be achieved by adopting a waste-to-energy system in the country. PMID:26821599

  19. Stoichiometry of the aerobic biodegradation of the organic fraction of municipal solid waste (MSW).

    Science.gov (United States)

    Liwarska-Bizukojc, Ewa; Ledakowicz, Stanislaw

    2003-01-01

    An elemental analysis was applied to describe the composition of the organic fraction of municipal solid waste (MSW). The initial elemental composition was constant at C5H8.5O4N0.2. The changes of the composition during the biodegradation process and the final waste composition were strictly dependent on the process conditions. The decrease in carbon content due to biodegradation increased with temperature at which the experiments were conducted, from 20% at 20 degrees C to about 40% at 37-42 degrees C after 96 hours. It was correlated with the amount of oxygen that was utilised in the investigated processes of aerobic biodegradation of the waste suspension. The amount of oxygen required for biodegradation of organic fraction of MSW was estimated on the basis of stoichiometric equations and increased from 0.92 moles per 1 mole of waste at 20 degrees C to 1.6 moles at 42 degrees C within 96 hours of the experiments. PMID:12801100

  20. Ozonolysis of α-pinene: parameterization of secondary organic aerosol mass fraction

    Directory of Open Access Journals (Sweden)

    R. K. Pathak

    2007-07-01

    Full Text Available Existing parameterizations tend to underpredict the α-pinene aerosol mass fraction (AMF or yield by a factor of 2–5 at low organic aerosol concentrations (<5 µg m−3. A wide range of smog chamber results obtained at various conditions (low/high NOx, presence/absence of UV radiation, dry/humid conditions, and temperatures ranging from 15–40°C collected by various research teams during the last decade are used to derive new parameterizations of the SOA formation from α-pinene ozonolysis. Parameterizations are developed by fitting experimental data to a basis set of saturation concentrations (from 10−2 to 104 µg m−3 using an absorptive equilibrium partitioning model. Separate parameterizations for α-pinene SOA mass fractions are developed for: 1 Low NOx, dark, and dry conditions, 2 Low NOx, UV, and dry conditions, 3 Low NOx, dark, and high RH conditions, 4 High NOx, dark, and dry conditions, 5 High NOx, UV, and dry conditions. According to the proposed parameterizations the α-pinene SOA mass fractions in an atmosphere with 5 µg m−3 of organic aerosol range from 0.032 to 0.1 for reacted α-pinene concentrations in the 1 ppt to 5 ppb range.

  1. Simulation of soil organic carbon in different soil size fractions using 13Carbon measurement data

    Science.gov (United States)

    Gottschalk, P.; Bellarby, J.; Chenu, C.; Foereid, B.; Wattenbach, M.; Zingore, S.; Smith, J.

    2009-04-01

    We simulate the soil organic carbon (SOC) dynamics at a chronoseqeunce site in France, using the Rothamsted Carbon model. The site exhibits a transition from C3 plants, dominated by pine forest, to a conventional C4 maize rotation. The different 13C signatures of the forest plants and maize are used to distinguish between the woodland derived carbon (C) and the maize derived C. The model is evaluated against total SOC and C derived from forest and maize, respectively. The SOC dynamics of the five SOC pools of the model, decomposable plant material (DPM), resistant plant material (RPM), biomass, humus and inert C, are also compared to the SOC dynamics measured in different soil size fractions. These fractions are > 50 μm (particulate organic matter), 2-50 μm (silt associated SOC) and 50 μm and the sum of the other pools corresponds well to the SOC measured in the soil size fraction stocks in the first 20 years after land-use change and overestimates the C accumulation of maize C. Several hypotheses were tested to evaluate the simulations. Input data and internal model parameter uncertainties had minor effects on the simulations results. Accounting for erosion and implementing a simple tillage routine did not improve the simulation fit to the data. We therefore hypothesize that a generic process that is not yet explicitly accounted for in the ROTHC model could explain the loss in soil C after land use change. Such a process could be the loss of the physical protection of soil organic matter as would be observed following cultivation of a previously uncultivated soil. Under native conditions a fraction of organic matter is protected in stable soil aggregates. These aggregates are physically disrupted by continuous and repeated cultivation of the soil. The underestimation of SOC loss by the model can be mainly attributed to the slow turnover of the humus pool. This pool was shown to represent mainly the SOC associated with the silt and clay soil fraction. Here, the

  2. Organic compounds in hot-water-soluble fractions from water repellent soils

    Science.gov (United States)

    Atanassova, Irena; Doerr, Stefan

    2014-05-01

    Water repellency (WR) is a soil property providing hydrophobic protection and preventing rapid microbial decomposition of organic matter entering the soil with litter or plant residues. Global warming can cause changes in WR, thus influencing water storage and plant productivity. Here we assess two different approaches for analysis of organic compounds composition in hot water extracts from accelerated solvent extraction (ASE) of water repellent soils. Extracts were lyophilized, fractionated on SiO2 (sand) and SPE cartridge, and measured by GC/MS. Dominant compounds were aromatic acids, short chain dicarboxylic acids (C4-C9), sugars, short chain fatty acids (C8-C18), and esters of stearic and palmitic acids. Polar compounds (mainly sugars) were adsorbed on applying SPE clean-up procedure, while esters were highly abundant. In addition to the removal of polar compounds, hydrophobic esters and hydrocarbons (alkanes and alkenes extracted through desorption of complex colloids stabilized as micelles in dissolved organic carbon (DOC). Water repellency was completely eliminated by hot water under high pressure. The molecular composition of HWSC can play a critical role in stabilization and destabilization of soil organic matter (SOM), particle wettability and C dynamics in soils. Key words: soil water repellency, hot water soluble carbon (HWSC), GC/MS, hydrophobic compounds

  3. Analysis of Organic Anionic Surfactants in Fine and Coarse Fractions of Freshly Emitted Sea Spray Aerosol

    Energy Technology Data Exchange (ETDEWEB)

    Cochran, Richard E.; Laskina, Olga; Jayarathne, Thilina; Laskin, Alexander; Laskin, Julia; Lin, Peng; Sultana, Camile M.; Lee, Christopher; Moore, Kathryn A.; Cappa, Christopher; Bertram, Timothy; Prather, Kimberly; Grassian, Vicki H.; Stone, Elizabeth

    2016-02-01

    The inclusion of organic compounds in freshly emitted sea spray aerosol (SSA) has been shown to be size-dependent, with an increasing organic fraction in smaller particles. Defining the molecular composition of sea spray aerosol has proven challenging, due to the mix of continental and background particles even in remote marine environments. Here we have used electrospray ionization-high resolution mass spectrometry in negative ion mode to identify organic compounds in nascent sea spray collected throughout a 25-day mesocosm experiment. Over 280 organic compounds from ten major homologous series were identified. These compounds were operationally defined as molecules containing a hydrophobic alkyl chain with a hydrophilic head group making them surface active. The most abundant class of molecules detected were saturated (C8–C24) and unsaturated (C12–C22) fatty acids. Fatty acid derivatives (including saturated oxo-fatty acids (C5–C18) and saturated hydroxy-fatty acids (C5–C18) were also identified. Interestingly, anthropogenic influences on SSA from the seawater were observed in the form of sulfate (C2–C7, C12–C17) and sulfonate (C16–C22) species. During the mesocosm, the distributions of molecules within each homologous series were observed to respond to variations among the levels of phytoplankton and bacteria in the seawater, indicating an important role of biological processes in determining the composition of SSA.

  4. Effects of Land Management Practices on Labile Organic Carbon Fractions in Rice Cultivation

    Institute of Scientific and Technical Information of China (English)

    SHAO Jing'an; LI Yangbing; WEI Chaofu; XIE Deti

    2009-01-01

    A research trial with four land management practices, I.e., traditional tillage-fallow (TTF), traditional till-age-wheat (TTW), conservation tillage-fallow (CTF) and conservation tillage-wheat (CTW), was sampled in the 15th year after its establishment to assess the effects of different management practices on labile organic carbon fractions (LOCFs), such as easily oxidizable organic carbon (EOC), dissolved organic carbon (DOC), particulate organic carbon (POC) and microbial biomass carbon (MBC) in a typical paddy soil, Chongqing, Southwest China. The results indi-cated that LOCFs were significantly influenced by the combination of no-tillage, ridge culture and crop rotation. And,different combination patterns showed different effectiveness on soil LOCFs. The effects of no-tillage, ridge culture and wheat cultivation on EOC, DOC, POC and MBC mainly happened at 0-10cm. At this depth, soil under CTW had higher EOC, DOC, POC and MBC contents, compared to TTF, TTW and CTF, respectively. Moreover, the contents of LOCFs for different practices generally decreased when the soil depth increased. Our findings suggest that the paddy soil in Southwest China could be managed to concentrate greater quantities of EOC, DOC, POC and MBC.

  5. Land-use related organic matter dynamics in North Cameroon soils assessed by C-13 analysis of soil organic matter fractions

    NARCIS (Netherlands)

    Sevink, J; Obale-Ebanga, F; Meijer, HAJ

    2005-01-01

    Topsoil samples from cultivated and adjacent non-cultivated fields on three major agricultural soils in North Cameroon were fractionated into particle-size fractions that were analysed subsequently for their C and C-13 contents. The aim was to obtain further insight into the dynamics of soil organic

  6. Long-term effects of mineral and organic fertilization on soil organic matter fractions and sorghum yield under Sudano-Sahelian conditions

    NARCIS (Netherlands)

    Mando, A.; Bonzi, M.; Wopereis, M.C.S.; Lompo, F.; Stroosnijder, L.

    2005-01-01

    Knowledge of changes in soil organic matter (SOM) fractions resulting from agricultural practice is important for decision-making at farm level because of the contrasting effects of different SOM fractions on soils. A long-term trial sited under Sudano-Sahelian conditions was used to assess the effe

  7. Use of radiocarbon and spectroscopic analyses to characterise soil organic matter pools isolated using different fractionation techniques.

    Science.gov (United States)

    Miller, Gemma; Cloy, Joanna; Garnett, Mark; Sohi, Saran; Rees, Robert; Griffiths, Bryan

    2015-04-01

    Experimental division of soil organic matter (SOM) into functional pools has the potential to improve soil C modelling. Soil physical fractionation techniques seek to quantify these pools, however the fractions isolated vary in number, size, ecological role and composition. The use of different techniques to quantify soil C fractions in different studies presents a question - do similar fractions isolated by different methods fit the same conceptual definition? This study examined a sandy loam from the south-west of Scotland, sampled in summer, which had been under grassland management for at least 20 years. We compared average 14C ages of SOM fractions isolated using three published and frequently applied physical fractionation methods (1) a density separation technique isolating three fractions - free light (FLF) 1.8 g cm 3 (Sohi et al, 2001); (2) a combined physical and chemical separation isolating five fractions: sand and aggregates (S+A) > 63 µm and > 1.8 g cm-3, particulate organic matter (POM) > 63 µm and 45 µm, residual organic carbon (rSOC) the residue left after s+c is oxidised with NaOCl, and dissolved organic carbon (DOC) 4000 years BP for DOC and POM. Both Method 3 fractions were dominated by modern C. The average 14C ages of FLF, IALF, DOC and POM were surprisingly higher than the mineral bound fractions, although they made up a relatively small proportion of the total organic C (8.4 and 12.4 % for Methods 1 and 2 respectively). These results will be discussed alongside data from FTIR and UV-vis spectroscopy. The characterisation of physically separated organic matter pools is likely to provide improved opportunities for modelling the long term behaviour of SOM on the basis of defined chemical and physical properties. References Sohi, S.P., Mahieu, N., Arah, J.R.M., Powlson, D.S., Madari, B. and Gaunt J.L. (2001) A procedure for isolating soil organic matter fractions suitable for modelling. Soil Science Society of America Journal 65

  8. An experimental investigation on intra-fractional organ motion effects in lung IMRT treatments

    Science.gov (United States)

    Jiang, Steve B.; Pope, Cynthia; Jarrah, Khaled M. Al; Kung, Jong H.; Bortfeld, Thomas; Chen, George T. Y.

    2003-06-01

    Respiration-induced tumour motion can potentially compromise the use of intensity-modulated radiotherapy (IMRT) as a dose escalation tool for lung tumour treatment. We have experimentally investigated the intra-fractional organ motion effects in lung IMRT treatments delivered by multi-leaf collimator (MLC). An in-house made motor-driven platform, which moves sinusoidally with an amplitude of 1 cm and a period of 4 s, was used to mimic tumour motion. Tumour motion was simulated along cranial-caudal direction while MLC leaves moved across the patient from left to right, as in most clinical cases. The dose to a point near the centre of the tumour mass was measured according to geometric and dosimetric parameters from two five-field lung IMRT plans. For each field, measurement was done for two dose rates (300 and 500 MU min-1), three MLC delivery modes (sliding window, step-and-shoot with 10 and 20 intensity levels) and eight equally spaced starting phases of tumour motion. The dose to the measurement point delivered from all five fields was derived for both a single fraction and 30 fractions by randomly sampling from measured dose values of each field at different initial phases. It was found that the mean dose to a moving tumour differs slightly (<2-3%) from that to a static tumour. The variation in breathing phase at the start of dose delivery results in a maximum variation around the mean dose of greater than 30% for one field. The full width at half maximum for the probability distribution of the point dose is up to 8% for all five fields in a single fraction, but less than 1-2% after 30 fractions. In general, lower dose rate can reduce the motion-caused dose variation and therefore might be preferable for lung IMRT when no motion mitigation techniques are used. From the two IMRT cases we studied where tumour motion is perpendicular to MLC leaf motion, the dose variation was found to be insensitive to the MLC delivery mode.

  9. An experimental investigation on intra-fractional organ motion effects in lung IMRT treatments

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Steve B; Pope, Cynthia; Jarrah, Al Khaled M; Kung, Jong H; Bortfeld, Thomas; Chen, George T Y [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114 (United States)

    2003-06-21

    Respiration-induced tumour motion can potentially compromise the use of intensity-modulated radiotherapy (IMRT) as a dose escalation tool for lung tumour treatment. We have experimentally investigated the intra-fractional organ motion effects in lung IMRT treatments delivered by multi-leaf collimator (MLC). An in-house made motor-driven platform, which moves sinusoidally with an amplitude of 1 cm and a period of 4 s, was used to mimic tumour motion. Tumour motion was simulated along cranial-caudal direction while MLC leaves moved across the patient from left to right, as in most clinical cases. The dose to a point near the centre of the tumour mass was measured according to geometric and dosimetric parameters from two five-field lung IMRT plans. For each field, measurement was done for two dose rates (300 and 500 MU min{sup -1}), three MLC delivery modes (sliding window, step-and-shoot with 10 and 20 intensity levels) and eight equally spaced starting phases of tumour motion. The dose to the measurement point delivered from all five fields was derived for both a single fraction and 30 fractions by randomly sampling from measured dose values of each field at different initial phases. It was found that the mean dose to a moving tumour differs slightly (<2-3%) from that to a static tumour. The variation in breathing phase at the start of dose delivery results in a maximum variation around the mean dose of greater than 30% for one field. The full width at half maximum for the probability distribution of the point dose is up to 8% for all five fields in a single fraction, but less than 1-2% after 30 fractions. In general, lower dose rate can reduce the motion-caused dose variation and therefore might be preferable for lung IMRT when no motion mitigation techniques are used. From the two IMRT cases we studied where tumour motion is perpendicular to MLC leaf motion, the dose variation was found to be insensitive to the MLC delivery mode.

  10. An experimental investigation on intra-fractional organ motion effects in lung IMRT treatments

    International Nuclear Information System (INIS)

    Respiration-induced tumour motion can potentially compromise the use of intensity-modulated radiotherapy (IMRT) as a dose escalation tool for lung tumour treatment. We have experimentally investigated the intra-fractional organ motion effects in lung IMRT treatments delivered by multi-leaf collimator (MLC). An in-house made motor-driven platform, which moves sinusoidally with an amplitude of 1 cm and a period of 4 s, was used to mimic tumour motion. Tumour motion was simulated along cranial-caudal direction while MLC leaves moved across the patient from left to right, as in most clinical cases. The dose to a point near the centre of the tumour mass was measured according to geometric and dosimetric parameters from two five-field lung IMRT plans. For each field, measurement was done for two dose rates (300 and 500 MU min-1), three MLC delivery modes (sliding window, step-and-shoot with 10 and 20 intensity levels) and eight equally spaced starting phases of tumour motion. The dose to the measurement point delivered from all five fields was derived for both a single fraction and 30 fractions by randomly sampling from measured dose values of each field at different initial phases. It was found that the mean dose to a moving tumour differs slightly (<2-3%) from that to a static tumour. The variation in breathing phase at the start of dose delivery results in a maximum variation around the mean dose of greater than 30% for one field. The full width at half maximum for the probability distribution of the point dose is up to 8% for all five fields in a single fraction, but less than 1-2% after 30 fractions. In general, lower dose rate can reduce the motion-caused dose variation and therefore might be preferable for lung IMRT when no motion mitigation techniques are used. From the two IMRT cases we studied where tumour motion is perpendicular to MLC leaf motion, the dose variation was found to be insensitive to the MLC delivery mode

  11. Characterisation of the biochemical methane potential (BMP) of individual material fractions in Danish source-separated organic household waste

    DEFF Research Database (Denmark)

    Naroznova, Irina; Møller, Jacob; Scheutz, Charlotte

    2016-01-01

    This study is dedicated to characterising the chemical composition and biochemical methane potential (BMP) of individual material fractions in untreated Danish source-separated organic household waste (SSOHW). First, data on SSOHW in different countries, available in the literature, were evaluated...... and then, secondly, laboratory analyses for eight organic material fractions comprising Danish SSOHW were conducted. No data were found in the literature that fully covered the objectives of the present study. Based on laboratory analyses, all fractions were assigned according to their specific properties...... in Denmark (untreated) was calculated, and the BMP contribution of the individual material fractions was then evaluated. Material fractions of the two general waste types, defined as "food waste" and "fibre-rich waste," were found to be anaerobically degradable with considerable BMP. Material degradability...

  12. Off-site impacts of agricultural composting: role of terrestrially derived organic matter in structuring aquatic microbial communities and their metabolic potential.

    Science.gov (United States)

    Pommier, Thomas; Merroune, Asmaa; Bettarel, Yvan; Got, Patrice; Janeau, Jean-Louis; Jouquet, Pascal; Thu, Thuy D; Toan, Tran D; Rochelle-Newall, Emma

    2014-12-01

    While considered as sustainable and low-cost agricultural amendments, the impacts of organic fertilizers on downstream aquatic microbial communities remain poorly documented. We investigated the quantity and quality of the dissolved organic matter leaching from agricultural soil amended with compost, vermicompost or biochar and assessed their effects on lake microbial communities, in terms of viral and bacterial abundances, community structure and metabolic potential. The addition of compost and vermicompost significantly increased the amount of dissolved organic carbon in the leachate compared with soil alone. Leachates from these additions, either with or without biochar, were highly bioavailable to aquatic microbial communities, although reducing the metabolic potential of the community and harbouring more specific communities. Although not affecting bacterial richness or taxonomic distributions, the specific addition of biochar affected the original lake bacterial communities, resulting in a strongly different community. This could be partly explained by viral burst and converging bacterial abundances throughout the samples. These results underline the necessity to include off-site impacts of agricultural amendments when considering their cascading effect on downstream aquatic ecosystems. PMID:25195703

  13. Is Zeolite a Detoxificant: Modelling of Ferrous Chloride/Zeolite Application of Aquatic Organisms on Rainbow Trout (Oncorhynchus mykiss to Determine Its Effects on Oxidative Stress

    Directory of Open Access Journals (Sweden)

    Arzu UÇAR

    2016-08-01

    Full Text Available Populations of native fish and aquatic ecosystems have been negatively affected by the contamination of ground and surface waters as a result of various activities. Due to the ferrous chloride (FeCl2, which is used as the reducing agent for the organic synthesis reactions in the contamination of water column and sediment, iron salts may be very toxic for some aquatic organism. In order to minimize these effects, natural products such as zeolite have been widely used recently. For this reason, rainbow trout (Oncorhynchus mykiss were exposed to FeCl2 and/or zeolite for 28 days and their oxidative stress responses were investigated. At the end of the treatment period, oxidative stress responses were determined with antioxidant enzyme activities in the samples taken from liver and kidneys. CAT, SOD, GPx and MDA values for kidney and liver tissues were found statistically important between control and treatment groups (p<0.05. In this study, zeolite application provided lower values in terms of enzyme activities, and the protective effect of zeolite for aquatic organism was supported by biochemical parameters. 

  14. Composition variability of the organic fraction of municipal solid waste and effects on hydrogen and methane production potentials.

    Science.gov (United States)

    Alibardi, Luca; Cossu, Raffaello

    2015-02-01

    The composition of the Organic Fraction of Municipal Solid Waste (OFMSW) strongly depends on the place and time of collection for a specific municipality or area. Moreover synthetic food waste or organic waste from cafeterias and restaurants may not be representative of the overall OFMSW received at treatment facilities for source-separated waste. This work is aimed at evaluating the composition variability of OFMSW, the potential productions of hydrogen and methane from specific organic waste fractions typically present in MSW and the effects of waste composition on overall hydrogen and methane yields. The organic waste fractions considered in the study were: bread-pasta, vegetables, fruits, meat-fish-cheese and undersieve 20mm. Composition analyses were conducted on samples of OFMSW that were source segregated at household level. Batch tests for hydrogen and methane productions were carried out under mesophilic conditions on selected fractions and OFMSW samples. Results indicated that the highest production of hydrogen was achieved by the bread-pasta fraction while the lowest productions were measured for the meat-fish-cheese fraction. The results indicated that the content of these two fractions in organic waste had a direct influence on the hydrogen production potentials of OFMSW. The higher the content of bread-pasta fraction, the higher the hydrogen yields were while the contrary was observed for the meat-fish-cheese fraction. The definition of waste composition therefore represents fundamental information to be reported in scientific literature to allow data comparison. The variability of OFMSW and its effects on hydrogen potentials might also represents a problematic issue in the management of pilot or full-scale plants for the production of hydrogen by dark fermentation. PMID:25529133

  15. Mineralization of organic phosphorus in soil size fractions under different vegetation covers in the north of Rio de Janeiro

    Directory of Open Access Journals (Sweden)

    Joice Cleide de Oliveira Rita

    2013-10-01

    Full Text Available In unfertilized, highly weathered tropical soils, phosphorus (P availability to plants is dependent on the mineralization of organic P (Po compounds. The objective of this study was to estimate the mineralization of total and labile Po in soil size fractions of > 2.0, 2.0-0.25 and 2.0 and 2.0-0.25 mm fractions, respectively. In contrast, there was an average increase of 90 % of total Po in microaggregates of 2.0 (-50 % and < 0.25 mm (-76 % fractions, but labile Po increased by 35 % in the 2.0-0.25 mm fraction. The Po fraction relative to total extracted P and total labile P within the soil size fractions varied with the vegetation cover and incubation time. Therefore, the distribution of P fractions (Pi and Po in the soil size fraction revealed the distinctive ability of the cover species to recycle soil P. Consequently, the potential of Po mineralization varied with the size fraction and vegetation cover. Because Po accounted for most of the total labile P, the P availability to plants was closely related to the mineralization of this P fraction.

  16. An experimental investigation on intra-fractional organ motion effects in lung IMRT treatments

    Science.gov (United States)

    Jiang, Steve B.; Pope, Cynthia; Jarrah, Khaled M. Al; Kung, Jong H.; Bortfeld, Thomas; Chen, George T. Y.

    2003-06-01

    Respiration-induced tumour motion can potentially compromise the use of intensity-modulated radiotherapy (IMRT) as a dose escalation tool for lung tumour treatment. We have experimentally investigated the intra-fractional organ motion effects in lung IMRT treatments delivered by multi-leaf collimator (MLC). An in-house made motor-driven platform, which moves sinusoidally with an amplitude of 1 cm and a period of 4 s, was used to mimic tumour motion. Tumour motion was simulated along cranial-caudal direction while MLC leaves moved across the patient from left to right, as in most clinical cases. The dose to a point near the centre of the tumour mass was measured according to geometric and dosimetric parameters from two five-field lung IMRT plans. For each field, measurement was done for two dose rates (300 and 500 MU min-1), three MLC delivery modes (sliding window, step-and-shoot with 10 and 20 intensity levels) and eight equally spaced starting phases of tumour motion. The dose to the measurement point delivered from all five fields was derived for both a single fraction and 30 fractions by randomly sampling from measured dose values of each field at different initial phases. It was found that the mean dose to a moving tumour differs slightly (lung IMRT when no motion mitigation techniques are used. From the two IMRT cases we studied where tumour motion is perpendicular to MLC leaf motion, the dose variation was found to be insensitive to the MLC delivery mode.

  17. N-15 NMR spectra of naturally abundant nitrogen in soil and aquatic natural organic matter samples of the International Humic Substances Society

    Science.gov (United States)

    Thorn, K.A.; Cox, L.G.

    2009-01-01

    The naturally abundant nitrogen in soil and aquatic NOM samples from the International Humic Substances Society has been characterized by solid state CP/MAS 15N NMR. Soil samples include humic and fulvic acids from the Elliot soil, Minnesota Waskish peat and Florida Pahokee peat, as well as the Summit Hill soil humic acid and the Leonardite humic acid. Aquatic samples include Suwannee River humic, fulvic and reverse osmosis isolates, Nordic humic and fulvic acids and Pony Lake fulvic acid. Additionally, Nordic and Suwannee River XAD-4 acids and Suwannee River hydrophobic neutral fractions were analyzed. Similar to literature reports, amide/aminoquinone nitrogens comprised the major peaks in the solid state spectra of the soil humic and fulvic acids, along with heterocyclic and amino sugar/terminal amino acid nitrogens. Spectra of aquatic samples, including the XAD-4 acids, contain resolved heterocyclic nitrogen peaks in addition to the amide nitrogens. The spectrum of the nitrogen enriched, microbially derived Pony Lake, Antarctica fulvic acid, appeared to contain resonances in the region of pyrazine, imine and/or pyridine nitrogens, which have not been observed previously in soil or aquatic humic substances by 15N NMR. Liquid state 15N NMR experiments were also recorded on the Elliot soil humic acid and Pony Lake fulvic acid, both to examine the feasibility of the techniques, and to determine whether improvements in resolution over the solid state could be realized. For both samples, polarization transfer (DEPT) and indirect detection (1H-15N gHSQC) spectra revealed greater resolution among nitrogens directly bonded to protons. The amide/aminoquinone nitrogens could also be observed by direct detection experiments.

  18. N-15 NMR spectra of naturally abundant nitrogen in soil and aquatic natural organic matter samples of the International Humic Substances Society

    Energy Technology Data Exchange (ETDEWEB)

    Thorn, Kevin A.; Cox, Larry G.

    2009-02-28

    The naturally abundant nitrogen in soil and aquatic NOM samples from the International Humic Substances Society has been characterized by solid state CP/MAS ¹⁵N NMR. Soil samples include humic and fulvic acids from the Elliot soil, Minnesota Waskish peat and Florida Pahokee peat, as well as the Summit Hill soil humic acid and the Leonardite humic acid. Aquatic samples include Suwannee River humic, fulvic and reverse osmosis isolates, Nordic humic and fulvic acids and Pony Lake fulvic acid. Additionally, Nordic and Suwannee River XAD-4 acids and Suwannee River hydrophobic neutral fractions were analyzed. Similar to literature reports, amide/aminoquinone nitrogens comprised the major peaks in the solid state spectra of the soil humic and fulvic acids, along with heterocyclic and amino sugar/terminal amino acid nitrogens. Spectra of aquatic samples, including the XAD-4 acids, contain resolved heterocyclic nitrogen peaks in addition to the amide nitrogens. The spectrum of the nitrogen enriched, microbially derived Pony Lake, Antarctica fulvic acid, appeared to contain resonances in the region of pyrazine, imine and/or pyridine nitrogens, which have not been observed previously in soil or aquatic humic substances by ¹⁵N NMR. Liquid state ¹⁵N NMR experiments were also recorded on the Elliot soil humic acid and Pony Lake fulvic acid, both to examine the feasibility of the techniques, and to determine whether improvements in resolution over the solid state could be realized. For both samples, polarization transfer (DEPT) and indirect detection (¹H–¹⁵N gHSQC) spectra revealed greater resolution among nitrogens directly bonded to protons. The amide/aminoquinone nitrogens could also be observed by direct detection experiments.

  19. Organic removal activity in biofilm and suspended biomass fractions of MBBR systems.

    Science.gov (United States)

    Piculell, Maria; Welander, Thomas; Jönsson, Karin

    2014-01-01

    The moving bed biofilm reactor (MBBR) wastewater treatment process is usually designed based on the assumption that all activity in the process occurs in the biofilm on the MBBR carriers, although there is always some active biomass in the bulk liquid due to biofilm sloughing and, sometimes, free-growing bacteria. In this study the removal of organic matter is evaluated in laboratory-scale MBBR reactors under varying load, hydraulic retention time (HRT), oxygen concentration and volumetric filling degree of carriers in order to determine the heterotrophic activity in the different fractions of the MBBR biomass. The results showed that the heterotrophic conversions in an MBBR can show the same type of diffusion limited dependency on oxygen as nitrification, even for easily degradable substrates such as acetate. The contribution to the removal from the suspended biomass is shown to vary depending on HRT, as the amount of suspended solids changes. The developed method in this report is a useful tool for determining heterotrophic activity in the separate fractions of biomass in MBBRs.

  20. Fractional release factors of long-lived halogenated organic compounds in the tropical stratosphere

    Directory of Open Access Journals (Sweden)

    J. C. Laube

    2010-02-01

    Full Text Available Fractional release factors (FRFs of organic trace gases are time-independent quantities that influence the calculation of Global Warming Potentials and Ozone Depletion Potentials. We present the first set of vertically resolved FRFs for 15 long-lived halocarbons in the tropical stratosphere up to 34 km altitude. They were calculated from measurements on air samples collected on board balloons and a high altitude aircraft. We compare the derived dependencies of FRFs on the mean stratospheric transit times (the so-called mean ages of air with similarly derived FRFs originating from measurements at higher latitudes and find significant differences. Moreover a comparison with averaged FRFs currently used by the World Meteorological Organisation revealed the limitations of these measures due to their observed vertical and latitudinal variability. The presented data set could be used to improve future ozone level and climate projections.

  1. Fractional release factors of long-lived halogenated organic compounds in the tropical stratosphere

    Directory of Open Access Journals (Sweden)

    J. C. Laube

    2009-09-01

    Full Text Available Fractional release factors (FRFs of organic trace gases are time-independent quantities that influence the calculation of Global Warming Potentials and Ozone Depletion Potentials. We present the first set of vertically resolved FRFs for 15 long-lived halocarbons in the tropical stratosphere up to 34 km altitude. They were calculated from measurements on air samples collected on board balloons and a high altitude aircraft. We compare the derived dependencies of FRFs on the mean stratospheric transit times (the so-called mean ages of air with similarly derived FRFs originating from measurements at higher latitudes and find significant differences. Moreover a comparison with averaged FRFs currently used by the World Meteorological Organisation revealed the latter to be imprecise measures due to their observed vertical and latitudinal variability. The presented data set could thus be used to improve future ozone level and climate projections.

  2. Fractionation of Moderately and Highly Stable Organic Phosphorus in Acid Soil

    Institute of Scientific and Technical Information of China (English)

    FANYEKUAN; LISHIJUN

    1998-01-01

    The fractionation of moderately and highly organic phosphorus(Po) in acid soil was studied by two methods .By the first method,after incubation for 40 d; the mineralization rates of eight constituents of stable Po in the soil were determined.By the second method ,five constituents of peecipitates of stable Po in the soil were separated,then the five precipiates were put back into the original soils and incubated for 40 d and 60 d .Then,mineralization rates of the five precipitates were determined.The same results were obtained by the two methods.When the pH of the alkali solution containing stable Po was adjusted from 3.00 to 3.10,the mineralization rate of moderately stable Po Was rapidly raised.Therefore,the pH 3.00 is the critical point between moderately and highly stable Po.

  3. Role of organic matter fractions in the Montney tight gas reservoir quality

    Science.gov (United States)

    Sanei, Hamed; Wood, James M.; Haeri Ardakani, Omid; Clarkson, Chris R.

    2015-04-01

    This study presents a new approach in Rock-Eval analysis to quantify various organic matter fractions in unconventional reservoirs. The results of study on core samples from the Triassic Montney Formation tight gas reservoir in the Western Canadian Sedimentary Basin show that operationally-defined S1 and S2 hydrocarbon peaks from conventional Rock-Eval analysis may not adequately characterize the organic constituents of unconventional reservoir rocks. Modification of the thermal recipe for Rock-Eval analysis, in conjunction with manual peak integration, provides important information with significance for the evaluation of reservoir quality. An adapted Rock-Eval method, herein called the extended slow heating (ESH) cycle, was developed in which the heating rate was slowed to 10°C per minute over an extended temperature range (150 to 650°C). For Montney core samples from the wet gas window, this method provided quantitative distinctions between major organic matter components of the rock. We show that the traditional S1 and S2 peaks can now be quantitatively divided into three components: (S1ESH) free light oil, (S2a ESH) condensed hydrocarbon residue (CHCR), and (S2b ESH + residual carbon) solid bitumen (refractory, consolidated bitumen/pyrobitumen). The majority of the total organic carbon (TOC) in the studied Montney core samples consists of solid bitumen that represents a former liquid oil phase which migrated into the larger paleo-intergranular pore spaces. Subsequent physicochemical changes to the oil environment led to the precipitation of asphaltene aggregates. Further diagenetic and thermal maturity processes consolidated these asphaltene aggregates into "lumps" of solid bitumen (or pyrobitumen at higher thermal maturity). Solid bitumen obstructs porosity and hinders fluid flow, and thus shows strong negative correlations with reservoir qualities such as porosity and pore throat size. We also find a strong positive correlation between the quantities of

  4. Gadolinium-uptake by aquatic and terrestrial organisms-distribution determined by laser ablation inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Lingott, Jana; Lindner, Uwe; Telgmann, Lena; Esteban-Fernández, Diego; Jakubowski, Norbert; Panne, Ulrich

    2016-02-01

    Gadolinium (Gd) based contrast agents (CA) are used to enhance magnetic resonance imaging. As a consequence of excretion by patients and insufficient elimination in wastewater treatment plants they are detected in high concentrations in surface water. At present, little is known about the uptake of these species by living organisms in aquatic systems. Therefore the uptake of gadolinium containing chelates by plants and animals grown in exposed water or on soil irrigated with exposed water was investigated. For this purpose two types of plants were treated with two different contrast agents. The uptake of the Gd contrast agents was studied by monitoring the elemental distribution with laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). This technique allows the multi-elemental analysis of solid samples with high resolution and little sample preparation. The analysis of L. minor showed that the uptake of Gd correlated with the concentration of gadodiamide in the water. The higher the concentration in the exposed water, the larger the Gd signal in the LA-ICP-MS acquired image. Exposure time experiments showed saturation within one day. The L. minor had contact with the CAs through roots and fronds, whereas the L. sativum only showed uptake through the roots. These results show that an external absorption of the CA through the leaves of L. sativum was impossible. All the analyzed parts of the plant showed Gd signal from the CA; the highest being at the main vein of the leaf. It is shown that the CAs can be taken up from plants. Furthermore, the uptake and distribution of Gd in Daphnia magna were shown. The exposure via cultivation medium is followed by Gd signals on the skin and in the area of the intestine, while the uptake via exposed nutrition algae causes the significantly highest Gd intensities in the area of the intestine. Because there are hints of negative effects for human organism these findings are important as they show that Gd based

  5. Hypoglycemic activity of leaf organic extracts from Smallanthus sonchifolius: Constituents of the most active fractions.

    Science.gov (United States)

    Genta, Susana B; Cabrera, Wilfredo M; Mercado, María I; Grau, Alfredo; Catalán, César A; Sánchez, Sara S

    2010-04-29

    The aim of the present study was to determine the in vivo hypoglycemic activity of five organic extracts and enhydrin obtained from yacon leaves. The main constituents of the most active fraction were identified. Five organic extracts and pure crystalline enhydrin were administered to normoglycemic, transiently hyperglycemic and streptozotocin (STZ)-diabetic rats. The fasting and post-prandial blood glucose, and serum insulin levels were estimated and an oral glucose tolerance test (OGTT) was performed for the evaluation of hypoglycemic activity and dose optimization of each extract. We found that the methanol, butanol and chloroform extracts showed effective hypoglycemic activity at minimum doses of 50, 10 and 20mg/kg body weight, respectively, and were selected for further experiments. Oral administration of a single-dose of each extract produced a slight lowering effect in the fasting blood glucose level of normal healthy rats, whereas each extract tempered significantly the hyperglycemic peak after food ingestion. Daily administration of each extract for 8 weeks produced an effective glycemic control in diabetic animals with an increase in the plasma insulin level. Phytochemical analysis of the most active fraction, the butanol extract, showed that caffeic, chlorogenic and three dicaffeoilquinic acids were significant components. Additionally, enhydrin, the major sesquiterpene lactone of yacon leaves, was also effective to reduce post-prandial glucose and useful in the treatment of diabetic animals (minimum dose: 0.8mg/kg body weight). The results presented here strongly support the notion that the phenolic compounds above as well as enhydrin are important hypoglycemic principles of yacon leaves that could ameliorate the diabetic state. PMID:20211156

  6. Deterrent activities in the crude lipophilic fractions of Antarctic benthic organisms: chemical defences against keystone predators

    Directory of Open Access Journals (Sweden)

    Laura Núñez-Pons

    2014-04-01

    Full Text Available Generalist predation constitutes a driving force for the evolution of chemical defences. In the Antarctic benthos, asteroids and omnivore amphipods are keystone opportunistic predators. Sessile organisms are therefore expected to develop defensive mechanisms mainly against such consumers. However, the different habits characterizing each predator may promote variable responses in prey. Feeding-deterrence experiments were performed with the circumpolar asteroid macropredator Odontaster validus to evaluate the presence of defences within the apolar lipophilic fraction of Antarctic invertebrates and macroalgae. A total of 51% of the extracts were repellent, yielding a proportion of 17 defended species out of the 31 assessed. These results are compared with a previous study in which the same fractions were offered to the abundant circum-Antarctic amphipod Cheirimedon femoratus. Overall, less deterrence was reported towards asteroids (51% than against amphipods (80.8%, principally in sponge and algal extracts. Generalist amphipods, which establish casual host–prey sedentary associations with biosubstrata (preferentially sponges and macroalgae, may exert more localized predation pressure than sea stars on certain sessile prey, which would partly explain these results. The nutritional quality of prey may interact with feeding deterrents, whose production is presumed to be metabolically expensive. Although optimal defence theory posits that chemical defences are managed and distributed as to guarantee protection at the lowest cost, we found that only a few organisms localized feeding deterrents towards most exposed and/or valuable body regions. Lipophilic defensive metabolites are broadly produced in Antarctic communities to deter opportunistic predators, although several species combine different defensive traits.

  7. Equilibrium of Organic Matter in Heavy Fraction for Three Long-term Experimental Field Soils in China

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Considerable evidence that the soil organic matter (OM) level in agricultural soils will gradually over time reach an equilibrium state under certain bioclimatic conditions and for certain cropping systems has been accumulating. Although models or long-term experiments have been used, this research used physical fractionation procedure to attain an soil OM equilibrium value. To obtain soil OM equilibrium values in the heavy fraction, typical soils from three long-term field experiments at Fengqiu and Yingtan State Key Agro-Ecological Experimental Stations in China were studied using a simple density fractionation procedure and employing the Langmuir equation. Results for the fluvo-aquic soil with organic fertilizer treatments indicated that the soil OM equilibrium value in the heavy fraction was twofold more than that in the inorganic treatments; however, for the paddy soil developed on red soil the OM equilibrium value in the heavy fraction for both treatments was almost identical. It suggested that for fluvo-aquic soils the increased potential of OM for the heavy fraction in the long run was larger for the organic than the inorganic fertilizer applications, whereas for paddy soils developed on red soils under the same conditions the present OM content in the heavy fraction was at or close to this equilibrium level for all treatments, and increased potential was very limited.

  8. Improved Cellulose and Organic-Solvents based Lignocellulosic Fractionation Pre-treatment of Organic Waste for Bioethanol Production

    Directory of Open Access Journals (Sweden)

    Valeriy Bekmuradov

    2014-06-01

    Full Text Available This study investigates the performance of the Cellulose and Organic-Solvents based Lignocellulosic Fractionation (COSLIF method for the pretreatment of Source-Separated Organic (SSO waste. An improvement on the standard method of COSLIF pre-treatment was developed based on lower enzyme loading and using an ethanol washing instead of acetone. It was demonstrated that a much higher glucose yield (90% after 72 hours was possible with this improvement, as compared to the original method, which yielded 70% in the same time frame. Evaluation of the enzymatic hydrolysate obtained from the modified COSLIF pretreatment was further examined by anaerobic fermentation with Zymomonas mobilis 8b strain. At 48 hours, ethanol concentration reached to 140 g/L, which is equivalent to 0.48 g of ethanol produced per gram of SSO biomass. This study demonstrated that the modified COSLIF pretreatment provides a substantial improvement over the standard method in terms of enzyme savings, glucose formation, and ethanol production.

  9. Fractionation of Fe isotopes during Fe(II) oxidation by a marine photoferrotroph is controlled by the formation of organic Fe-complexes and colloidal Fe fractions

    Science.gov (United States)

    Swanner, Elizabeth D.; Wu, Wenfang; Schoenberg, Ronny; Byrne, James; Michel, F. Marc; Pan, Yongxin; Kappler, Andreas

    2015-09-01

    Much interest exists in finding mineralogical, organic, morphological, or isotopic biosignatures for Fe(II)-oxidizing bacteria (FeOB) that are retained in Fe-rich sediments, which could indicate the activity of these organisms in Fe-rich seawater, more common in the Precambrian Era. To date, the effort to establish a clear Fe isotopic signature in Fe minerals produced by Fe(II)-oxidizing metabolisms has been thwarted by the large kinetic fractionation incurred as freshly oxidized aqueous Fe(III) rapidly precipitates as Fe(III) (oxyhydr)oxide minerals at near neutral pH. The Fe(III) (oxyhydr)oxide minerals resulting from abiotic Fe(II) oxidation are isotopically heavy compared to the Fe(II) precursor and are not clearly distinguishable from minerals formed by FeOB isotopically. However, in marine hydrothermal systems and Fe(II)-rich springs the minerals formed are often isotopically lighter than expected considering the fraction of Fe(II) that has been oxidized and experimentally-determined fractionation factors. We measured the Fe isotopic composition of aqueous Fe (Feaq) and the final Fe mineral (Feppt) produced in batch experiment using the marine Fe(II)-oxidizing phototroph Rhodovulum iodosum. The δ56Feaq data are best described by a kinetic fractionation model, while the evolution of δ56Feppt appears to be controlled by a separate fractionation process. We propose that soluble Fe(III), and Fe(II) and Fe(III) extracted from the Feppt may act as intermediates between Fe(II) oxidation and Fe(III) precipitation. Based on 57Fe Mössbauer spectroscopy, extended X-ray absorption fine structure (EXAFS) spectroscopy, and X-ray total scattering, we suggests these Fe phases, collectively Fe(II/III)interm, may consist of organic-ligand bound, sorbed, and/or colloidal Fe(II) and Fe(III) mineral phases that are isotopically lighter than the final Fe(III) mineral product. Similar intermediate phases, formed in response to organic carbon produced by FeOB and inorganic

  10. Changes of Labile Organic Carbon Fractions in Soils Under Different Rotation Systems

    Institute of Scientific and Technical Information of China (English)

    NI Jin-Zhi; XU Jian-Ming; XIE Zheng-Miao; WANG De-Jian

    2004-01-01

    Soil labile (biologically active) organic carbon fractions under different crop rotation systems in Jiangsu Province, China, were investigated after 10 years of rotation. The rotation systems, including green manurerice-rice (GmRR), wheat-rice-rice (WRR), wheat-rice (WR) and wheat/corn intercrop-rice (WCR) rotations,were established on paddy soils using a randomized complete block design with three replicates. The total organic carbon (TOC), total nitrogen (TN) and water-soluble organic carbon (WSOC) in the soils under different systems were greater in the GmRR and WRR than in the WR and WCR rotation systems because the soils under triple cropping often received more crop residues than the soils under double cropping. Both the WSOC and the microbial biomass carbon (MBC) contents in the soils of the GmRR rotation system were significantly greater than those in the other crop rotation systems, which was due to the return of green manure to the fields of the GmRR rotation system. The results of a 13C nuclear magnetic resonance (13C-NMR) analysis indicated that the structural characteristics of soil WSOC were similar under the four crop rotation systems with carbohydrates and long-chain aliphatics being the major components. Correlation analysis showed that the content of the WSOC was positively correlated with that of the MBC (P <0.01),and all had significantly positive correlations with TOC and TN. The coefficients of variation (CVs) for WSOC and WSOC/TOC were greater than the other indices (e.g, MBC, TOC and TN), suggesting that WSOC in the soils was more sensitive to these rotation systems. The results above indicated that the soil amended with green manure could not only increase the usable C source for soil microorganisms, but could also enhance soil organic matter content; hence, rotation with green manure would be a good strategy for sustainable agriculture.

  11. Identification of effluent organic matter fractions responsible for low-pressure membrane fouling

    KAUST Repository

    Filloux, Emmanuelle

    2012-11-01

    Anion exchange resin (AER), powder activated carbon (PAC) adsorption and ozonation treatments were applied on biologically treated wastewater effluent with the objective to modify the effluent organic matter (EfOM) matrix. Both AER and PAC led to significant total organic carbon (TOC) removal, while the TOC remained nearly constant after ozonation. Liquid Chromatography-Organic Carbon Detection (LC-OCD) analysis showed that the AER treatment preferentially removed high and intermediate molecular weight (MW) humic-like structures while PAC removed low MW compounds. Only a small reduction of the high MW colloids (i.e. biopolymers) was observed for AER and PAC treatments. Ozonation induced a large reduction of the biopolymers and an important increase of the low MW humic substances (i.e. building blocks).Single-cycle microfiltration (MF) and ultrafiltration (UF) tests were conducted using commercially available hollow fibres at a constant flux. After reconcentration to their original organic carbon content, the EfOM matrix modified by AER and PAC treatments exhibited higher UF membrane fouling compared to untreated effluent; result that correlated with the higher concentration of biopolymers. On the contrary, ozonation which induced a significant degradation of the biopolymers led to a minor flux reduction for both UF and MF filtration tests. Based on a single filtration, results indicate that biopolymers play a major role in low pressure membrane fouling and that intermediate and low MW compounds have minor impact. Thus, this approach has shown to be a valid methodology to identify the foulant fractions of EfOM. © 2012 Elsevier Ltd.

  12. Organic fraction of municipal solid waste from mechanical selection: biological stabilization and recovery options.

    Science.gov (United States)

    Cesaro, Alessandra; Russo, Lara; Farina, Anna; Belgiorno, Vincenzo

    2016-01-01

    Although current trends address towards prevention strategies, the organic fraction of municipal solid waste is greatly produced, especially in high-income contexts. Its recovery-oriented collection is a common practice, but a relevant portion of the biodegradable waste is not source selected. Mechanical and biological treatments (MBT) are the most common option to sort and stabilize the biodegradable matter ending in residual waste stream. Following the changes of the framework around waste management, this paper aimed at analyzing the quality of the mechanically selected organic waste produced in MBT plants, in order to discuss its recovery options. The material performance was obtained by its composition as well as by its main chemical and physical parameters; biological stability was also assessed by both aerobic and anaerobic methods. On this basis, the effectiveness of an aerobic biostabilization process was assessed at pilot scale. After 21 days of treatment, results proved that the biomass had reached an acceptable biostabilization level, with a potential Dynamic Respirometric Index (DRIP) value lower than the limit required for its use as daily or final landfill cover material. However, the final stabilization level was seen to be influenced by scaling factors and the 21 days of treatment turned to be not so adequate when applied in the existing full-scale facility.

  13. [Intensification of Microbial Decomposition of Organic Fraction of Municipal Waste: Laboratory and Field Experiments].

    Science.gov (United States)

    Nikitina, A A; Kevbrina, M V; Kallistova, A Yu; Nekrasova, V K; Litti, Yu V; Nozhevnikova, A N

    2015-01-01

    Methods of intensifying the anaerobic microbial decomposition of the organic fraction of municipal solid waste (MSW) on an MSW landfill and in anaerobic reactors were studied. It was discovered that it is preferable for the initiation and stabilization of the process of anaerobic digestion of organic waste in laboratory bioreactors at 20 and 50 degrees C to use a mixture of activated suspension of soil from the anaerobic zone of the landfill and digested sewage sludge. Stimulation of methanogenesis was shown in field conditions when digested sewage sludge was added directly into the upper layer of anaerobic zone of the landfill. The investigation of methane production during fermentation of concentrated food waste with a mixture of excessive activated sludge in the laboratory under thermophilic conditions (50 degrees C) has shown that the main problem at the first stage of the process was the acidification of the digested mixture due to the accumulation of volatile fatty acids. It was shown that for stable operation of the bioreactor under thermophilic conditions the amount of inoculum added during the start up should be no less than 30%-50%--based on volatile suspended solids. A sharp decrease in the digestion temperature from 50 to 20 degrees C did not cause methanogenesis termination, since the thermophilically fermented biomass contained both thermophilic and mesophilic methanogens.

  14. Oxidizable fraction of organic carbon in an argisol under different land use systems

    Directory of Open Access Journals (Sweden)

    José Fernando Scaramuzza

    2012-06-01

    Full Text Available The objective of this study was to evaluate carbon input in labile and stable fractions in an ARGISOL of northwestern Brazil under different land use systems. Use systems being evaluated include: forest - MA (reference, agrosilvopasture – TCP (teak, cocoa and pasture; agroforest – TC (teak and cocoa; teak forest at 8 and 5 years – T8 and T5, and pasture - PA. In each system three furrows were made at depths of 0-5 cm, 5-10 cm and 10-20 cm. An area consisting of native vegetation (forest adjacent to the experiment was sampled and used as control treatment. The use systems MA, T8 and T5 had higher levels of total organic carbon (COT and the MA system had higher levels of labile carbon (CL than the other systems, with the exception of TC at a depth of 10-20 cm. In the MA system, COT levels were higher in comparison to use systems TCP, TC and PA while CL levels were higher than the levels observed in use systems TCP and TC. In most cases being analyzed, CL levels were lower than COT levels, therefore this trait can be used as an indicator to assess anthropogenic changes relating to the maintenance or condition of soil organic matter.

  15. Hydrolysis and thermophilic anaerobic digestion of sewage sludge and organic fraction of municipal solid waste

    Energy Technology Data Exchange (ETDEWEB)

    Del Borghi, A.; Converti, A.; Palazzi, E.; Del Borghi, M. [Institute of Chemical and Process Engineering ``G.B. Bonino``, Genoa University, Via Opera Pia 15, 16145 Genoa (Italy)

    1999-06-01

    An attempt is presented and discussed to adapt a well-known process successfully employed in the U.S.A. for the simultaneous treatment of the organic fraction of municipal solid waste (MSWOF) and sewage sludge to the particular situation of water works in Italy. It consists of preliminary domestic grinding of MSWOF, its discharge into the sewer, screening, and final digestion of the resulting residue together with sewage sludge. In order to avoid extension work of the present activated sludge sections necessary to face the organic load increase, a fine screening is necessary, while the efficiency of anaerobic digestion can be improved by shifting the system from mesophilic (37 C) to thermophilic (55 C) conditions. The effects of thermal, chemical, and biological pretreatments of both MSWOF and sewage sludge on methane, carbon dioxide, and biogas productions are investigated either separately or jointly. During these pretreatments, volatile suspended solid (VSS) concentration remarkably decreased while soluble chemical oxygen demand (COD) increased as the result of the progressive hydrolysis of the polymeric materials present in the feed. Finally, the kinetic parameters of the hydrolysis of these materials are estimated and compared in order to provide useful information on the factors limiting the anaerobic digestion as well as to suggest the best way to carry out the process on a large scale. (orig.) With 8 figs., 7 tabs., 20 refs.

  16. Organic fraction of municipal solid waste from mechanical selection: biological stabilization and recovery options.

    Science.gov (United States)

    Cesaro, Alessandra; Russo, Lara; Farina, Anna; Belgiorno, Vincenzo

    2016-01-01

    Although current trends address towards prevention strategies, the organic fraction of municipal solid waste is greatly produced, especially in high-income contexts. Its recovery-oriented collection is a common practice, but a relevant portion of the biodegradable waste is not source selected. Mechanical and biological treatments (MBT) are the most common option to sort and stabilize the biodegradable matter ending in residual waste stream. Following the changes of the framework around waste management, this paper aimed at analyzing the quality of the mechanically selected organic waste produced in MBT plants, in order to discuss its recovery options. The material performance was obtained by its composition as well as by its main chemical and physical parameters; biological stability was also assessed by both aerobic and anaerobic methods. On this basis, the effectiveness of an aerobic biostabilization process was assessed at pilot scale. After 21 days of treatment, results proved that the biomass had reached an acceptable biostabilization level, with a potential Dynamic Respirometric Index (DRIP) value lower than the limit required for its use as daily or final landfill cover material. However, the final stabilization level was seen to be influenced by scaling factors and the 21 days of treatment turned to be not so adequate when applied in the existing full-scale facility. PMID:26377969

  17. Long-term fertilization effects on soil organic carbon fractions in a red soil of southern China

    Science.gov (United States)

    Tong, X.; Xu, M.; Wang, X.; Zhang, W.; Cong, R.

    2010-12-01

    This paper presents a study of long-term (17 years) fertilization effects on soil organic carbon (SOC) fractions in a typical red soil (Ferralic Cambisol) under intensive cropping with maize-wheat with various fertilizations in Hunan, China. The fertilization treatments include non-fertilization (Control), mineral nitrogen (N), mineral nitrogen-phosphorus (NP), nitrogen-phosphorus-potassium combination (NPK), and mineral NPK combined with organic amendments (e.g., pig manure and straw). Two sets of soil samples were used: (1) collected in 1990, and (2) collected in 2007. Soil samples were separated to measure free particulate organic C (fPOC), intra-microaggregate particulate organic C (iPOC), and mineral associated organic C (MOC) with physical fractionation. The percentage of SOC fractions in all treatments follows an order: MOC (45-89%) >fPOC (7-35%) >iPOC (11-20%), suggesting that MOC is the primary organic carbon pool in the red soil. Compared with the control, there is no increase in iPOC and MOC under imbalanced mineral fertilizer applications (i.e., N, NP). However, all SOC fractions show a significant increase under balanced mineral fertilizer application (NPK), and mineral NPK applied with organic amendments. Particularly, manure application results in an increase of 290.6-408.3 kg ha-1 yr-1 for fPOC, 162.0-179.2 kg ha-1 yr-1 for iPOC and 322.9-514.5 kg ha-1 yr-1 for MOC.

  18. Passive internal transport of aquatic organisms by waterfowl in Doñana, south-west Spain.

    NARCIS (Netherlands)

    Figuerola, J.; Green, J.; Santamaria, L.

    2003-01-01

    Aim Waterbirds may play an important role in the maintenance of aquatic ecosystem biodiversity by transporting plants and invertebrate propagules between different wetlands. The aim of this study is to provide the first quantitative analysis of the transport of plant and animal propagules by a commu

  19. Acid-base and copper-binding properties of three organic matter fractions isolated from a forest floor soil solution

    OpenAIRE

    van Schaik, Joris W. J.; Kleja, Dan B.; Gustafsson, Jon Petter

    2010-01-01

    Vast amounts of knowledge about the proton- and metal-binding properties of dissolved organic matter (DOM) in natural waters have been obtained in studies on isolated humic and fulvic (hydrophobic) acids. Although macromolecular hydrophilic acids normally make up about one-third of DOM, their proton- and metal-binding properties are poorly known. Here, we investigated the acid-base and Cu-binding properties of the hydrophobic (fulvic) acid fraction and two hydrophilic fractions isolated from ...

  20. Large-fraction preoperative irradiation in combination with organ-sparing surgery for first- or second-stage breast cancer

    International Nuclear Information System (INIS)

    A method of combined organ-sparing treatment for first-or second-stage breast cancer has been developed. It includes large-fraction preoperative radiation (28.5 Gy in 5 daily fractions) and segmental mastectomy with axillary lymphadenectomy. The method has been used in 25 patients. Mean follow-up time is 23 months. No local or regional relapses have been recorded. Total relapse-free survival is 92%. The cosmetic and functional effect is satisfactory

  1. Sulfur isotope fractionation during bacterial sulfate reduction in organic-rich sediments

    DEFF Research Database (Denmark)

    Habicht, K S; Canfield, D E

    1997-01-01

    Isotope fractionation during sulfate reduction by natural populations of sulfate-reducing bacteria was investigated in the cyanobacterial microbial mats of Solar Lake, Sinai and the sediments of Logten Lagoon sulfuretum, Denmark. Fractionation was measured at different sediment depths, sulfate...

  2. Defining an exposure-response relationship for suspended kaolin clay particulates and aquatic organisms: work toward defining a water quality guideline for suspended solids.

    Science.gov (United States)

    Gordon, Andrew K; Palmer, Carolyn G

    2015-04-01

    Water quality guidelines for suspended solids generally rely on the percentage departure from reference condition, an approach that has been criticized. Attempts to develop a biological effects-base guideline have, however, been confounded by low data availability. Furthermore, the high biological response variability to suspended solids exposure suggests that organisms are responding not only to exposure concentration and duration but also to other mechanisms of effect associated with suspended particles (e.g., size, shape, and geochemical composition). An alternative option is to develop more situation and site specific guidelines by generating biological effects data to suspended particles of a particular geochemistry and restricted size range. With this in mind, aquatic organism responses to kaolin clay particle exposure were collated from the literature and incorporated into 2 exposure-response relationship approaches. The species sensitivity distribution approach produced a hazardous concentration affecting 5% of species estimate of 58 mg/L for mortality responses, and 36 mg/L for sublethal data. The severity-of-ill-effect approach produced similar estimates for lethal and sublethal data. These results suggest that aquatic organisms are slightly more tolerant of kaolin clay particles than particles from barite or bentonite clays, based on results from previous studies on these clay types. This type of information can enable better estimates of the risk faced by aquatic organisms exposed to suspended solids. For example, when the sediments of a particular water body are dominated by a particular type of clay particle, then the most appropriate exposure-response relationship can be applied.

  3. Separation of inerts by differential sedimentation as previous stage to anaerobic digestion of organic fraction from municipal solid waste

    International Nuclear Information System (INIS)

    Municipal solid waste (MSW) treatment plants have as main function the valuation of municipal waste by means of materials recovery and valuation of organic fraction. In this type of facilities, the anaerobic digestion is a biological treatment of the organic matter collected in origin or mechanically separated from the mixed MSM. The objective is its valuation under the form of biogas and organic compost. Anaerobic digestion has high energy efficiency and a good range or organic matter elimination. Nevertheless, treatment of organic matter recovered from mixed MSW presents serious operation problems due to sedimentation of heavy improper materials (sands, glasses, metals) and flotation of light materials inside the digestors and piping. (Author)

  4. Distribution of light and heavy fractions of soil organic carbon as related to land use and tillage practice

    Science.gov (United States)

    Tan, Zhengxi; Lal, R.; Owens, L.; Izaurralde, R. C.

    2007-01-01

    Mass distributions of different soil organic carbon (SOC) fractions are influenced by land use and management. Concentrations of C and N in light- and heavy fractions of bulk soils and aggregates in 0–20 cm were determined to evaluate the role of aggregation in SOC sequestration under conventional tillage (CT), no-till (NT), and forest treatments. Light- and heavy fractions of SOC were separated using 1.85 g mL−1 sodium polytungstate solution. Soils under forest and NT preserved, respectively, 167% and 94% more light fraction than those under CT. The mass of light fraction decreased with an increase in soil depth, but significantly increased with an increase in aggregate size. C concentrations of light fraction in all aggregate classes were significantly higher under NT and forest than under CT. C concentrations in heavy fraction averaged 20, 10, and 8 g kg−1 under forest, NT, and CT, respectively. Of the total SOC pool, heavy fraction C accounted for 76% in CT soils and 63% in forest and NT soils. These data suggest that there is a greater protection of SOC by aggregates in the light fraction of minimally disturbed soils than that of disturbed soil, and the SOC loss following conversion from forest to agriculture is attributed to reduction in C concentrations in both heavy and light fractions. In contrast, the SOC gain upon conversion from CT to NT is primarily attributed to an increase in C concentration in the light fraction.

  5. Methodology of comprehensive evaluation of the effectiveness and reliability of production lines of preparation of sea water for the cultivation of aquatic organisms

    Directory of Open Access Journals (Sweden)

    S. D. Ugryumova

    2016-01-01

    Full Text Available The factors affecting the efficiency and reliability of technical systems. Set stages of development and modernization of production lines that correspond to specific stages of evaluating the effectiveness and reliability. Considered several methods of definition of indicators of indicators of efficiency and reliability of the equipment in technological lines of fisheries sector: forecasting methods, structural methods, physical methods, logical-probability method (method by I.A. Ryabinin and topological method. Advantages and disadvantages, allowing you to work out the most suitable method, process lines preparation of sea water for the cultivation of aquatic organisms, connected in series. Modernized technological line of preparation of sea water for the cultivation of aquatic organisms differing from the typical line of seawater in hatcheries (Far East, as the presence of a large number of instrumentation: sensors, salinity and temperature; motomeru that continuously monitor turbidity in the range of 50÷100 EMF (30÷60 mg/1 by kaolin; signaling the flow sensors volume level of the filtrate and the backfill layer; analyzers of chemical composition of sea water; analyzers of suspended mechanical impurities; signaling sensors of acidity and oxygen content and replacement filters coarse, fine cleaning and auxiliary equipment. A program of comprehensive evaluation of the effectiveness and reliability of production lines, revealed that conducted the modernization of production line preparation of sea water for the cultivation of aquatic organisms has improved its efficiency by an average of 1.71% to reduce the amount of manual labor by 15.1%; control the process; provide the most rapid, efficient purification of sea water; reduce the cost of replacement filter media.

  6. PHA production from the organic fraction of municipal solid waste (OFMSW): Overcoming the inhibitory matrix.

    Science.gov (United States)

    Korkakaki, Emmanouela; Mulders, Michel; Veeken, Adrie; Rozendal, Rene; van Loosdrecht, Mark C M; Kleerebezem, Robbert

    2016-06-01

    Leachate from the source separated organic fraction of municipal solid waste (OFMSW) was evaluated as a substrate for polyhydroxyalkanoates (PHA) production. Initially, the enrichment step was conducted directly on leachate in a feast-famine regime. Maximization of the cellular PHA content of the enriched biomass yielded to low PHA content (29 wt%), suggesting that the selection for PHA-producers was unsuccessful. When the substrate for the enrichment was switched to a synthetic volatile fatty acid (VFA) mixture -resembling the VFA carbon composition of the leachate-the PHA-producers gained the competitive advantage and dominated. Subsequent accumulation with leachate in nutrient excess conditions resulted in a maximum PHA content of 78 wt%. Based on the experimental results, enriching a PHA-producing community in a "clean" VFA stream, and then accumulating PHA from a stream that does not allow for enrichment but does enable a high cellular PHA content, such as OFMSW leachate, makes the overall process much more economically attractive. The estimated overall process yield can be increased four-fold, in comparison to direct use of the complex matrix for both enrichment and accumulation. PMID:27019467

  7. Micro-scale anaerobic digestion of point source components of organic fraction of municipal solid waste.

    Science.gov (United States)

    Chanakya, H N; Sharma, Isha; Ramachandra, T V

    2009-04-01

    The fermentation characteristics of six specific types of the organic fraction of municipal solid waste (OFMSW) were examined, with an emphasis on properties that are needed when designing plug-flow type anaerobic bioreactors. More specifically, the decomposition patterns of a vegetable (cabbage), fruits (banana and citrus peels), fresh leaf litter of bamboo and teak leaves, and paper (newsprint) waste streams as feedstocks were studied. Individual OFMSW components were placed into nylon mesh bags and subjected to various fermentation periods (solids retention time, SRT) within the inlet of a functioning plug-flow biogas fermentor. These were removed at periodic intervals, and their composition was analyzed to monitor decomposition rates and changes in chemical composition. Components like cabbage waste, banana peels, and orange peels fermented rapidly both in a plug-flow biogas reactor (PFBR) as well as under a biological methane potential (BMP) assay, while other OFMSW components (leaf litter from bamboo and teak leaves and newsprint) fermented slowly with poor process stability and moderate biodegradation. For fruit and vegetable wastes (FVW), a rapid and efficient removal of pectins is the main cause of rapid disintegration of these feedstocks, which left behind very little compost forming residues (2-5%). Teak and bamboo leaves and newsprint decomposed only to 25-50% in 30d. These results confirm the potential for volatile fatty acids accumulation in a PFBR's inlet and suggest a modification of the inlet zone or operation of a PFBR with the above feedstocks. PMID:19081239

  8. Investigating organic molecules responsible of auxin-like activity of humic acid fraction extracted from vermicompost.

    Science.gov (United States)

    Scaglia, Barbara; Nunes, Ramom Rachide; Rezende, Maria Olímpia Oliveira; Tambone, Fulvia; Adani, Fabrizio

    2016-08-15

    This work studied the auxin-like activity of humic acids (HA) obtained from vermicomposts produced using leather wastes plus cattle dung at different maturation stages (fresh, stable and mature). Bioassays were performed by testing HA concentrations in the range of 100-6000mgcarbonL(-1). (13)C CPMAS-NMR and GC-MS instrumental methods were used to assess the effect of biological processes and starting organic mixtures on HA composition. Not all HAs showed IAA-like activity and in general, IAA-like activity increased with the length of the vermicomposting process. The presence of leather wastes was not necessary to produce the auxin-like activity of HA, since HA extracted from a mix of cattle manure and sawdust, where no leather waste was added, showed IAA-like activity as well. CPMAS (13)CNMR revealed that HAs were similar independently of the mix used and that the humification process involved the increasing concentration of pre-existing alkali soluble fractions in the biomass. GC/MS allowed the identification of the molecules involved in IAA-like effects: carboxylic acids and amino acids. The concentration of active molecules, rather than their simple presence in HA, determined the bio-stimulating effect, and a good linear regression between auxin-like activity and active stimulating molecules concentration was found (R(2)=-0.85; p<0.01, n=6). PMID:27100009

  9. Mixing effect on thermophilic anaerobic digestion of source-sorted organic fraction of municipal solid waste

    KAUST Repository

    Ghanimeh, Sophia A.

    2012-08-01

    This paper examines the effect of mixing on the performance of thermophilic anaerobic digestion of source-sorted organic fraction of municipal solid waste during the start-up phase and in the absence of an acclimated seed. For this purpose, two digesters were used under similar starting conditions and operated for 235days with different mixing schemes. While both digesters exhibited a successful startup with comparable specific methane yield of 0.327 and 0.314l CH 4/gVS, continuous slow stirring improved stability by reducing average VFA accumulation from 2890 to 825mg HAc/l, propionate content from 2073 to 488mg/l, and VFA-to-alkalinity ratio from 0.32 to 0.07. As a result, the startup with slow mixing was faster and smoother accomplishing a higher loading capacity of 2.5gVS/l/d in comparison to 1.9gVS/l/d for non-mixing. Mixing equally improved microbial abundance from 6.6 to 10gVSS/l and enhanced solids and soluble COD removal. © 2012 Elsevier Ltd.

  10. Co-digestion of the hydromechanically separated organic fraction of municipal solid waste with sewage sludge.

    Science.gov (United States)

    Borowski, Sebastian

    2015-01-01

    This study investigates the anaerobic digestion of the hydromechanically sorted organic fraction of municipal solid wastes (HS-OFMSW) co-digested with sewage sludge (SS). Eight laboratory-scale experiments were conducted under semi-continuous conditions at 15 and 20 days of solids retention time (SRT). The biogas yield from the waste reached 309 to 315 dm(3)/kgVS and 320 to 361 dm(3)/kgVS under mesophilic and thermophilic conditions, respectively. The addition of SS to HS-OFMSW (1:1 by weight) improved the C/N balance of the mixture, and the production of biogas through anaerobic mesophilic digestion increased to 494 dm(3)/kgVS, which corresponded to 316 dm(3)CH4/kgVS. However, when SS and HS-OFMSW were treated under thermophilic conditions, methanogenesis was inhibited by volatile fatty acids and free ammonia, which concentrations reached 5744 gCH3COOH/m(3) and 1009 gNH3/m(3), respectively. PMID:25262391

  11. Carbon Isotopic Fractionation During Formation of Macromolecular Organic Grain Coatings via FTT Reactions

    Science.gov (United States)

    Nuth, J. A.; Johnson, N. M.; Elsila-Cook, J.; Kopstein, M.

    2011-01-01

    Observations of carbon isotopic fractionation of various organic compounds found in meteorites may provide useful diagnostic information concerning the environments and mechanisms that were responsible for their formation. Unfortunately, carbon has only two stable isotopes, making interpretation of such observations quite problematic. Chemical reactions can increase or decrease the C-13/C-12 ratio by various amounts, but the final ratio will depend on the total reaction pathway followed from the source carbon to the final product, a path not readily discernable after 4.5 billion years. In 1970 Libby showed that the C-13/C-12 ratios of terrestrial and meteoritic carbon were similar by comparing carbon from the Murchison meteorite to that of terrestrial sediments. More recent studies have shown that the C-13/C-12 ratio of the Earth and meteorites may be considerably enriched in C-13 compared to the ratio observed in the solar wind [2], possibly suggesting that carbon produced via ion-molecule reactions in cold dark clouds could be an important source of terrestrial and meteoritic carbon. However, meteoritic carbon has been subjected to parent body processing that could have resulted in significant changes to the C-13/C-12 ratio originally present while significant variation has been observed in the C-13/C-12 ratio of the same molecule extracted from different terrestrial sources. Again we must conclude that understanding the ratio found in meteorites may be difficult.

  12. Organization of vegetation cover of aquatic ecosystems at Borodinskiy opencast coal mine dumps (Kansk forest-steppe, Eastern Siberia

    Directory of Open Access Journals (Sweden)

    D. Yu. Efimov

    2016-04-01

    Full Text Available The paper present the results of study of the floristic composition and importance of species of aquatic ecosystems on different types of technogenic surfaces of the Borodino coal mine and assessment of the impact of local factors on the structure and the dynamics of vegetation. The list of plant taxa containing 91 species of higher plants and 3 cha-rophytes. The largest amount of macrophytes species are Elodea canadensis Michx., Eleocharis palustris (L. Roem. & Schult., Hydrocharis morsus-ranae L., Potamogeton alpinus Balb., P. perfoliatus L., Sparganium emersum Rehm., Spirodela polyrhiza (L. Schleid., Typha latifolia L., Warnstorfia fluitans (Hedw. Loeske, Chara contraria A. Braun ex Kutz., the basis (up to 67.6‒70.9 % of vegetation mosaic of aquatic systems and differentiate its structure post-technogenic landscape. Sorensen index (QS = 0.63‒0.71 and Spearman rank correlation coefficient (rs = 0.29‒0.62, p < 0.01 values showed the greatest similarity between the species composition of the aquatic complexes arising on mineral surfaces planned dumps. The low level of similarity (QS = 0.13‒0.45; rs = 0.25‒0.34, p < 0.05 in spe-cies composition is typical fir ponds and wetlands formed around the perimeter of the heaps along the erosion of slopes. Non-parametric analysis of variance showed a statistically significant (p < 0.001 differentiation of the species composition of the variables values of the analyzed environmental factors: the direction of reclamation, type and age of geomorphic surfaces dumps. Aquatic complexes significantly complement and enrich the mosaic of man-made landscape of the Borodino coal mine, the potential of their diversity should be taken into account when developing plans and strategies for reclamation of disturbed areas.

  13. Determination of the composition of the organic matter chemically stabilized by agricultural soil clay minerals: Spectroscopy and Density Fractionation

    Science.gov (United States)

    Oufqir, Sofia; Bloom, Paul; Toner, Brandy; Hatcher, Patrick

    2014-05-01

    The interactions between soil organic matter and clay minerals are considered important processes because of their ability to sequester C in soil for long periods of time, and hence control C in the global C cycle when present. However, differing results have been reported regarding the composition of the soil organic matter - aromatic fractions versus aliphatic fractions - associated with clay minerals. To clarify this critical issue and better understand the C sequestration process in soils, we aimed to determine the nature of the chemically bound natural organic matter on clay surfaces, and to probe the speciation and spatial distribution of C in the soil clay nanoparticles using direct spectroscopic measurements namely solid-state CP-MAS and DP-MAS 13C NMR spectroscopy, x-ray diffraction spectroscopy (XRD), and scanning transmission x-ray microscopy (STXM). We tested the hypotheses that peptides and polysaccharides are stabilized by the smectite-illite clay while the lipids and black carbon are a separate phase; and that they are evenly distributed on clay surfaces. A soil clay fraction (5.5% organic C) was isolated from the surface of a prairie soil (Mollisol) in southwestern Minnesota, characterized by a pH 6.0, 32.5% clay content, and 3.7% organic carbon, using a sonication-sedimentation-siphoning process in distilled water. Then was subjected to density separation combined with low energy ultrasonic dispersion to separate the free organic and black C (light fraction) from the chemically bound C (heavy fraction). The XRD results indicated a dominance of interstratified smectite-illite clays in soil. The 13C-NMR spectra of the soil clay fraction suggested that polysaccharides and polypeptides are the prevailing components of the organic matter associated with the mineral clay, with only a minor component of aromatic C. The light fraction has strong alkyl C-H bands characteristic of fatty acids plus strong C-O bands characteristic of polysaccharides, including

  14. Spectral study of the complexation of Nd(III) with glutathione reduced (GSH) in the presence and absence of Zn(II) in aquated organic solvents

    Indian Academy of Sciences (India)

    Th David Singh; Ch Sumitra; N Rajmuhon Singh; M Indira Devi

    2004-11-01

    Studies on the difference in energy parameters and comparative absorption spectrophotometry involving 4-4 transitions on Nd(III) and glutathione reduced (GSH) in the absence and presence of Zn(II) have been carried out in aquated organic solvents (50 : 50) like methanol, dioxane, acetonitrile and dimethylformamide. Variations in the spectral energy parameters - Slater-Condon () factor, Lande spin-orbit coupling constant (4), nephelauxetic ratio (), bonding parameter (1/2) and percent covalency () - are calculated and correlated with binding of Nd(III) with GSH in presence and absence of Zn(II).

  15. Cover plants and mineral nitrogen: effects on organic matter fractions in an oxisol under no-tillage in the cerrado

    Directory of Open Access Journals (Sweden)

    Isis Lima dos Santos

    2014-12-01

    Full Text Available Cover plants are essential for the sustainability of no-tillage systems in tropical regions. However, information on the effects of these plants and N fertilization on soil organic matter fractions is still scarce. This study evaluated the effect of cover crops with different chemical composition and of N topdressing on the labile and humified organic matter fractions of an Oxisol of the Cerrado (savanna-like vegetation. The study in a randomized complete block design was arranged in split-plots with three replications. Four cover species were tested in the plots and the presence or absence of N topdressing in the subplot. The following cover species were planted in succession to corn for eight years: Urochloa ruziziensis; Canavalia brasiliensis M. ex Benth; Cajanus cajan (L. Millsp; and Sorghum bicolor (L. Moench. In general, the cultivation of U. ruziziensis increased soil C levels, particularly of C in the humic acid and particulate organic C fractions, which are quality indicators of soil organic matter. The C in humic substances and mineral organic C accounted for the highest proportions of total organic C, demonstrating the strong interaction between organic matter, Fe and Al oxides and kaolinite, which are predominant in these weathered soils of the Cerrado.

  16. Soil organic carbon and nitrogen content of density fractions and effect of meadow degradation to soil carbon and nitrogen of fractions in alpine Kobresia meadow

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    This research was conducted on the non-disturbed native alpine Kobresia meadow(YF) and the severely degraded meadow(SDL) of Dari County of Qinghai Province.By a density fractionation approach,each soil sample was divided into two fractions:light fraction(LF) and heavy fraction(HF).The obtained fractions were analyzed for organic carbon(OC) and nitrogen(N) concentrations.The results showed:(1) the OC concentration in HF and LF was 3.84% and 28.63% respectively while the nitrogen concentration in HF and LF was 0.362% and 1.192% respectively in 0-10 cm depth.C:N ratio was 10.6 in HF and 23.8 in LF respectively.(2) As far as the ratio of OC in given fraction to that in gross sample was concerned,dominance of OC in HF was obvious in the whole soil profile.OC in HF increased from 78.95% to 90.33%,while OC in LF decreased from 21.05% to 9.68% with depths.(3) Soil total OC amounted to 47.47 in YF while 17.63 g.kg-1 in SDL,in which the OC content in HF decreased from 37.31 to 16.01 g.kg-1 while OC content in LF decreased from 10.01 to 1.62 g.kg-1.In other words,results of OC and N content show meadow degradation led to the loss of 57% OC in HF and 84% OC in LF from originally native ecosystem on alpine meadow.In addition,meadow degradation led to the loss of 43% N in HF and 79% N in LF from originally native ecosystem on alpine meadow.(4) The main reason for loss of C and N in LF during meadow degradation was not attributed to the decrease of OC and N concentration in LF and LF,but to the decrease in LF dry weight.Loss of N was far lower than loss of C in HF.This may suggest that there is difference in protection mode of C and N in HF.

  17. Insights on the Phytochemical Profile (Cyclopeptides and Biological Activities of Calotropis procera Latex Organic Fractions

    Directory of Open Access Journals (Sweden)

    Thiago Lustosa Jucá

    2013-01-01

    Full Text Available Calotropis procera is a medicinal plant whose pharmacological properties are associated with its latex. Here, the Calotropis procera latex fractions were investigated in an attempt to trace its phytochemical profile and measure its anti-inflammatory and toxicity activity. The crude latex was partitioned, yielding five fractions (49.4% hexane, 5.2% dichloromethane, 2.0% ethyl acetate, 2.1% n-butanol, and 41.1% aqueous. Phytochemical screening and spectroscopy analysis revealed that dichloromethane is the most chemically diverse fraction. Triterpenes were detected in both the hexane and dichloromethane fractions, while flavonoids were detected in the dichloromethane and ethyl acetate fractions. These fractions were cytotoxic to cancer cell lines (LD50 0.05 to 3.9 μg/mL and lethal to brine shrimp (LD50 10.9 to 65.7 μg/mL. Reduced neutrophil migration in rats was observed in carrageenan-induced peritonitis for the dichloromethane (67%, ethyl acetate (56%, and aqueous (72% fractions. A positive reaction with tolidine and ninhydrin suggested that cyclopeptides are in the ethyl acetate fraction. It is therefore concluded that Calotropis procera latex dichloromethane and ethyl acetate fractions exhibit both in vitro and in vivo activities as well as anti-inflammatory properties. Cyclopeptide detection is especially interesting because previous attempts to investigate these low-molecular cyclic amino acid sequences in C. procera have failed.

  18. Capacity of soil to protect organic carbon and biochemical characteristics of density fractions in Ziwulin Haplic Greyxems soil

    Institute of Scientific and Technical Information of China (English)

    WANG Gang; WANG Chunyan; WANG Wenying; WANG Qiji

    2005-01-01

    Physical protection is one of the important ways to stabilize organic carbon in soils. In order to understand the role of soils as a carbon sink or source in global climatic change and carbon cycles and properly manage soils as a carbon sink, we ought to know how many organic carbon (OC) in a given soil could be protected. By a density fractionation approach and ultrasonic technique, each soil sample was divided into three fractions: free light fraction (free-LF), occluded fraction (occluded-LF) and heavy fraction (HF). The obtained fractions were analyzed for total OC content, carbohydrate content and recalcitrant OC content. The results showed: (ⅰ) In the whole soil profile, dominance of OC consistently decreased in the following order: HF, free-LF, occluded-LF. This suggested that OC in soils were mostly protected. From 0-10 to 60-80 cm horizons, the OC in free-LF decreased from 25.27% to 3.72%, while OC in HF they were increased from 72.57% to 95.39%. The OC in occluded-LF was between 2.16% and 0.89%. (ⅱ) Organic carbon recalcitrance in free-LF was similar to that in HF, and was even higher than that in HF below the surface horizon. This suggested that free-LF was not always the most fresh and non-decomposed fraction. OM quality of HF was higher than that of free-LF in the surface 10 cm below, namely the protected OM had higher quality than free OM in these horizons.

  19. Response of Soil Organic Carbon and Its Aggregate Fractions to Long-Term Fertilization in Irrigated Desert Soil of China

    Institute of Scientific and Technical Information of China (English)

    CHAI Yan-jun; ZENG Xi-bai; E Sheng-zhe; HUANG Tao; CHE Zong-xian; SU Shi-ming; BAI Ling-yu

    2014-01-01

    Irrigated desert soil samples in the Hexi Corridor of China were collected over a period of 23 years from a site where different fertilization methods had been used. Changes of soil organic carbon (SOC) and its water stable aggregate (WSA) size fractions were studied. The effects of various fertilization methods on the distribution of added organic carbon (OC) in different WSA size fractions were also analyzed. The results showed that the applied fertilizations for 23 years improved SOC concentrations and OC concentrations in all WSA size fractions compared to the non-fertilized treatment (CK). In addition, fertilization obviously increased the OC stocks of2 mm, 0.25-2 mm and 0.053-0.25 mm WSA fractions, respectively. A signiifcant positive correlation was found between soil C gains and OC inputs (r=0.92, P<0.05), indicating that SOC may have not reached the saturation point yet at the site. The C sequestration rate was estimated by 14.02%at the site. The OC stocks in all of the<2 mm WSA fractions increased with the increase of OC input amounts;and the conversion rate of the input fresh OC to the OC stock of<0.053 mm WSA fraction was 1.2 and 2.6 times higher than those of the 0.25-2 mm and 0.053-0.25 mm WSA fractions, respectively. Therefore, the<0.053 mm WSA fraction was the most important component for soil C sequestration in the irrigated desert soil.

  20. 40 CFR Table 3 to Subpart Pppp of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Default Organic HAP Mass Fraction for Solvents and Solvent Blends 3 Table 3 to Subpart PPPP of Part 63 Protection of Environment ENVIRONMENTAL... of Plastic Parts and Products Pt. 63, Subpt. PPPP, Table 3 Table 3 to Subpart PPPP of Part...

  1. 40 CFR Table 4 to Subpart Pppp of... - Default Organic HAP Mass Fraction for Petroleum Solvent Groups a

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Default Organic HAP Mass Fraction for Petroleum Solvent Groups a 4 Table 4 to Subpart PPPP of Part 63 Protection of Environment ENVIRONMENTAL... of Plastic Parts and Products Pt. 63, Subpt. PPPP, Table 4 Table 4 to Subpart PPPP of Part...

  2. Aniline and 2,4,6-trinitrotoluene associate preferentially to low molecular weight fractions of dissolved soil organic matter

    International Nuclear Information System (INIS)

    Aniline and 2,4,6-trinitrotoluene (TNT) were equilibrated with particulate (POM) and dissolved organic matter (DOM) from an organic soil at different compositions of adsorbed major cations (Na, Al) and pH (aniline: 3.7-5.1, TNT: 4.8-5.0). After separation of POM, concentrations of 14C-labelled aniline and TNT* (including TNT degradation products) were determined in DOM size fractions using size-exclusion chromatography (SEC) and UV-detection. Concentrations in the 40 kDa fraction. Thus, both aniline and TNT* were preferentially associated to the smallest DOM size fraction. The significant binding to DOM (similar extent as to POM) and the fact that the <3.5 kDa DOM fraction was less susceptible to flocculation by major metals suggests that the mobility of aniline and TNT is highly affected by the solubility of soil organic matter. - Concentrations of aniline and TNT associated with dissolved organic matter (DOM) was shown to increase with decreasing apparent molecular mass of DOM.

  3. Aquatic Sediments.

    Science.gov (United States)

    Sanville, W. D.; And Others

    1978-01-01

    Presents a literature review of aquatic sediments and its effect upon water quality, covering publications of 1976-77. This review includes: (1) sediment water interchange; (2) chemical and physical characterization; and (3) heavy water in sediments. A list of 129 references is also presented. (HM)

  4. Total organic carbon and humus fractions in restored soils from limestone quarries in semiarid climate, SE Spain

    Science.gov (United States)

    Luna Ramos, Lourdes; Miralles Mellado, Isabel; Ángel Domene Ruiz, Miguel; Solé Benet, Albert

    2016-04-01

    Mining activities generate erosion and loss of plant cover and soil organic matter (SOM), especially in arid and semiarid Mediterranean regions. A precondition for ecosystem restoration in such highly disturbed areas is the development of functional soils with sufficient organic matter. But the SOM quality is also important to long-term C stabilization. The resistance to biodegradation of recalcitrant organic matter fractions has been reported to depend on some intrinsic structural factors of humic acid substances and formation of amorphous organo-mineral recalcitrant complexes. In an experimental soil restoration in limestone quarries in the Sierra de Gádor (Almería), SE Spain, several combinations of organic amendments (sewage sludge and compost from domestic organic waste) and mulches (gravel and woodchip) were added in experimental plots using a factorial design. In each plot, 75 native plants (Anthyllis cytisoides, A. terniflora and Macrochloa tenacissima) were planted and five years after the start of the experiment total organic carbon (TOC), physico-chemical soil properties and organic C fractions (particulate organic matter, H3PO4-fulvic fraction, fulvic acids (FA), humic acids (HA) and humin) were analyzed. We observed significant differences between treatments related to the TOC content and the HA/FA ratio. Compost amendments increased the TOC, HA content and HA/FA ratio, even higher than in natural undisturbed soils, indicating an effective clay humus-complex pointing to progressively increasing organic matter quality. Soils with sewage sludge showed the lowest TOC and HA/FA ratio and accumulated a lower HA proportion indicating poorer organic matter quality and comparatively lower resilience than in natural soils and soils amended with compost.

  5. A Physically Based Framework for Modelling the Organic Fractionation of Sea Spray Aerosol from Bubble Film Langmuir Equilibria

    Energy Technology Data Exchange (ETDEWEB)

    Burrows, Susannah M.; Ogunro, O.; Frossard, Amanda; Russell, Lynn M.; Rasch, Philip J.; Elliott, S.

    2014-12-19

    The presence of a large fraction of organic matter in primary sea spray aerosol (SSA) can strongly affect its cloud condensation nuclei activity and interactions with marine clouds. Global climate models require new parameterizations of the SSA composition in order to improve the representation of these processes. Existing proposals for such a parameterization use remotely-sensed chlorophyll-a concentrations as a proxy for the biogenic contribution to the aerosol. However, both observations and theoretical considerations suggest that existing relationships with chlorophyll-a, derived from observations at only a few locations, may not be representative for all ocean regions. We introduce a novel framework for parameterizing the fractionation of marine organic matter into SSA based on a competitive Langmuir adsorption equilibrium at bubble surfaces. Marine organic matter is partitioned into classes with differing molecular weights, surface excesses, and Langmuir adsorption parameters. The classes include a lipid-like mixture associated with labile dissolved organic carbon (DOC), a polysaccharide-like mixture associated primarily with semi-labile DOC, a protein-like mixture with concentrations intermediate between lipids and polysaccharides, a processed mixture associated with recalcitrant surface DOC, and a deep abyssal humic-like mixture. Box model calculations have been performed for several cases of organic adsorption to illustrate the underlying concepts. We then apply the framework to output from a global marine biogeochemistry model, by partitioning total dissolved organic carbon into several classes of macromolecule. Each class is represented by model compounds with physical and chemical properties based on existing laboratory data. This allows us to globally map the predicted organic mass fraction of the nascent submicron sea spray aerosol. Predicted relationships between chlorophyll-\\textit{a} and organic fraction are similar to existing empirical

  6. A physically based framework for modeling the organic fractionation of sea spray aerosol from bubble film Langmuir equilibria

    Directory of Open Access Journals (Sweden)

    S. M. Burrows

    2014-12-01

    Full Text Available The presence of a large fraction of organic matter in primary sea spray aerosol (SSA can strongly affect its cloud condensation nuclei activity and interactions with marine clouds. Global climate models require new parameterizations of the SSA composition in order to improve the representation of these processes. Existing proposals for such a parameterization use remotely sensed chlorophyll a concentrations as a proxy for the biogenic contribution to the aerosol. However, both observations and theoretical considerations suggest that existing relationships with chlorophyll a, derived from observations at only a few locations, may not be representative for all ocean regions. We introduce a novel framework for parameterizing the fractionation of marine organic matter into SSA based on a competitive Langmuir adsorption equilibrium at bubble surfaces. Marine organic matter is partitioned into classes with differing molecular weights, surface excesses, and Langmuir adsorption parameters. The classes include a lipid-like mixture associated with labile dissolved organic carbon (DOC, a polysaccharide-like mixture associated primarily with semilabile DOC, a protein-like mixture with concentrations intermediate between lipids and polysaccharides, a processed mixture associated with recalcitrant surface DOC, and a deep abyssal humic-like mixture. Box model calculations have been performed for several cases of organic adsorption to illustrate the underlying concepts. We then apply the framework to output from a global marine biogeochemistry model, by partitioning total dissolved organic carbon into several classes of macromolecules. Each class is represented by model compounds with physical and chemical properties based on existing laboratory data. This allows us to globally map the predicted organic mass fraction of the nascent submicron sea spray aerosol. Predicted relationships between chlorophyll a and organic fraction are similar to existing empirical

  7. A physically-based framework for modelling the organic fractionation of sea spray aerosol from bubble film Langmuir equilibria

    Directory of Open Access Journals (Sweden)

    S. M. Burrows

    2014-03-01

    Full Text Available The presence of a large fraction of organic matter in primary sea spray aerosol (SSA can strongly affect its cloud condensation nuclei activity and interactions with marine clouds. Global climate models require new parameterizations of the SSA composition in order to improve the representation of these processes. Existing proposals for such a parameterization use remotely-sensed chlorophyll a concentrations as a proxy for the biogenic contribution to the aerosol. However, both observations and theoretical considerations suggest that existing relationships with chlorophyll a, derived from observations at only a few locations, may not be representative for all ocean regions. We introduce a novel framework for parameterizing the fractionation of marine organic matter into SSA based on a competitive Langmuir adsorption equilibrium at bubble surfaces. Marine organic matter is partitioned into classes with differing molecular weights, surface excesses, and Langmuir adsorption parameters. The classes include a lipid-like mixture associated with labile dissolved organic carbon (DOC, a polysaccharide-like mixture associated primarily with semi-labile DOC, a protein-like mixture with concentrations intermediate between lipids and polysaccharides, a processed mixture associated with recalcitrant surface DOC, and a deep abyssal humic-like mixture. Box model calculations have been performed for several cases of organic adsorption to illustrate the underlying concepts. We then apply the framework to output from a global marine biogeochemistry model, by partitioning total dissolved organic carbon into several classes of macromolecules. Each class is represented by model compounds with physical and chemical properties based on existing laboratory data. This allows us to globally map the predicted organic mass fraction of the nascent submicron sea spray aerosol. Predicted relationships between chlorophyll a and organic fraction are similar to existing empirical

  8. Histological examination of the effect of differently fractionated irradiations in rat and mouse organs. Pt. 3

    International Nuclear Information System (INIS)

    The spleen of rats was irradiated with 50 Gy dose local X-rays in two different fractionation rhythms, i.e. twice a week given high and daily applied lower fractions of radiation. According to the results of 3H-thymidine autoradiography made after the last irradiation 24 hours later both in the white and the red pulp the labelling index was less on the effect of twice in a week applied high radiation fractions than in case of daily given lower fractions. This indicate in correlation with the results of earlier analogous histological experiments that the damaging effect of rarely given higher fractions of radiation in the spleen is especially obvious. (orig.)

  9. Thermal and mechanical stabilization process of the organic fraction of the municipal solid waste.

    Science.gov (United States)

    Giudicianni, Paola; Bozza, Pio; Sorrentino, Giancarlo; Ragucci, Raffaele

    2015-10-01

    In the present study a thermo-mechanical treatment for the disposal of the Organic Fraction of Municipal Solid Waste (OFMSW) at apartment or condominium scale is proposed. The process presents several advantages allowing to perform a significant volume and moisture reduction of the produced waste at domestic scale thus producing a material with an increased storability and improved characteristics (e.g. calorific value) that make it available for further alternative uses. The assessment of the applicability of the proposed waste pretreatment in a new scheme of waste management system requires several research steps involving different competences and application scales. In this context, a preliminary study is needed targeting to the evaluation and minimization of the energy consumption associated to the process. To this aim, in the present paper, two configurations of a domestic appliance prototype have been presented and the effect of some operating variables has been investigated in order to select the proper configuration and the best set of operating conditions capable to minimize the duration and the energy consumption of the process. The performances of the prototype have been also tested on three model mixtures representing a possible daily domestic waste and compared with an existing commercially available appliance. The results obtained show that a daily application of the process is feasible given the short treatment time required and the energy consumption comparable to the one of the common domestic appliances. Finally, the evaluation of the energy recovered in the final product per unit weight of raw material shows that in most cases it is comparable to the energy required from the treatment. PMID:26209343

  10. Stable carbon isotope fractionation of organic cyst-forming dinoflagellates: Evaluating the potential for a CO2 proxy

    Science.gov (United States)

    Hoins, Mirja; Van de Waal, Dedmer B.; Eberlein, Tim; Reichart, Gert-Jan; Rost, Björn; Sluijs, Appy

    2015-07-01

    Over the past decades, significant progress has been made regarding the quantification and mechanistic understanding of stable carbon isotope fractionation (13C fractionation) in photosynthetic unicellular organisms in response to changes in the partial pressure of atmospheric CO2 (pCO2). However, hardly any data is available for organic cyst-forming dinoflagellates while this is an ecologically important group with a unique fossil record. We performed dilute batch experiments with four harmful dinoflagellate species known for their ability to form organic cysts: Alexandrium tamarense, Scrippsiella trochoidea, Gonyaulax spinifera and Protoceratium reticulatum. Cells were grown at a range of dissolved CO2 concentrations characterizing past, modern and projected future values (∼5-50 μmol L-1), representing atmospheric pCO2 of 180, 380, 800 and 1200 μatm. In all tested species, 13C fractionation depends on CO2 with a slope of up to 0.17‰ (μmol L)-1. Even more consistent correlations were found between 13C fractionation and the combined effects of particulate organic carbon quota (POC quota; pg C cell-1) and CO2. Carbon isotope fractionation as well as its response to CO2 is species-specific. These results may be interpreted as a first step towards a proxy for past pCO2 based on carbon isotope ratios of fossil organic dinoflagellate cysts. However, additional culture experiments focusing on environmental variables other than pCO2, physiological underpinning of the recorded response, testing for possible offsets in 13C values between cells and cysts, as well as field calibration studies are required to establish a reliable proxy.

  11. Fabrication of nano-mosquitocides using chitosan from crab shells: Impact on non-target organisms in the aquatic environment.

    Science.gov (United States)

    Murugan, Kadarkarai; Anitha, Jaganathan; Dinesh, Devakumar; Suresh, Udaiyan; Rajaganesh, Rajapandian; Chandramohan, Balamurugan; Subramaniam, Jayapal; Paulpandi, Manickam; Vadivalagan, Chitravel; Amuthavalli, Pandiyan; Wang, Lan; Hwang, Jiang-Shiou; Wei, Hui; Alsalhi, Mohamad Saleh; Devanesan, Sandhanasamy; Kumar, Suresh; Pugazhendy, Kannaiyan; Higuchi, Akon; Nicoletti, Marcello; Benelli, Giovanni

    2016-10-01

    Mosquitoes are arthropods of huge medical and veterinary relevance, since they vector pathogens and parasites of public health importance, including malaria, dengue and Zika virus. Currently, nanotechnology is considered a potential eco-friendly approach in mosquito control research. We proposed a novel method of biofabrication of silver nanoparticles (AgNP) using chitosan (Ch) from crab shells. Ch-AgNP nanocomposite was characterized by UV-vis spectroscopy, FTIR, SEM, EDX and XRD. Ch-AgNP were tested against larvae and pupae of the malaria vector Anopheles stephensi obtaining LC50 ranging from 3.18 ppm (I) to 6.54 ppm (pupae). The antibacterial properties of Ch-AgNP were proved against Bacillus subtilis, Klebsiella pneumoniae and Salmonella typhi, while no growth inhibition was reported in assays conducted on Proteus vulgaris. Concerning non-target effects, in standard laboratory considtions the predation efficiency of Danio rerio zebrafishes was 68.8% and 61.6% against I and II instar larvae of A. stephensi, respectively. In a Ch-AgNP-contaminated environment, fish predation was boosted to 89.5% and 77.3%, respectively. Quantitative analysis of antioxidant enzymes SOD, CAT and LPO from hepatopancreas of fresh water crabs Paratelphusa hydrodromous exposed for 16 days to a Ch-AgNP-contaminated aquatic environment were conducted. Notably, deleterious effects of Ch-AgNP contaminating aquatic enviroment on the non-target crab P. hydrodromous were observed, particularly when doses higher than 8-10ppm are tested. Overall, this research highlights the potential of Ch-AGNP for the development of newer control tools against young instar populations of malaria mosquitoes, also highlighting some risks concerned the employ of nanoparticles in aquatic environments. PMID:27344400

  12. Fabrication of nano-mosquitocides using chitosan from crab shells: Impact on non-target organisms in the aquatic environment.

    Science.gov (United States)

    Murugan, Kadarkarai; Anitha, Jaganathan; Dinesh, Devakumar; Suresh, Udaiyan; Rajaganesh, Rajapandian; Chandramohan, Balamurugan; Subramaniam, Jayapal; Paulpandi, Manickam; Vadivalagan, Chitravel; Amuthavalli, Pandiyan; Wang, Lan; Hwang, Jiang-Shiou; Wei, Hui; Alsalhi, Mohamad Saleh; Devanesan, Sandhanasamy; Kumar, Suresh; Pugazhendy, Kannaiyan; Higuchi, Akon; Nicoletti, Marcello; Benelli, Giovanni

    2016-10-01

    Mosquitoes are arthropods of huge medical and veterinary relevance, since they vector pathogens and parasites of public health importance, including malaria, dengue and Zika virus. Currently, nanotechnology is considered a potential eco-friendly approach in mosquito control research. We proposed a novel method of biofabrication of silver nanoparticles (AgNP) using chitosan (Ch) from crab shells. Ch-AgNP nanocomposite was characterized by UV-vis spectroscopy, FTIR, SEM, EDX and XRD. Ch-AgNP were tested against larvae and pupae of the malaria vector Anopheles stephensi obtaining LC50 ranging from 3.18 ppm (I) to 6.54 ppm (pupae). The antibacterial properties of Ch-AgNP were proved against Bacillus subtilis, Klebsiella pneumoniae and Salmonella typhi, while no growth inhibition was reported in assays conducted on Proteus vulgaris. Concerning non-target effects, in standard laboratory considtions the predation efficiency of Danio rerio zebrafishes was 68.8% and 61.6% against I and II instar larvae of A. stephensi, respectively. In a Ch-AgNP-contaminated environment, fish predation was boosted to 89.5% and 77.3%, respectively. Quantitative analysis of antioxidant enzymes SOD, CAT and LPO from hepatopancreas of fresh water crabs Paratelphusa hydrodromous exposed for 16 days to a Ch-AgNP-contaminated aquatic environment were conducted. Notably, deleterious effects of Ch-AgNP contaminating aquatic enviroment on the non-target crab P. hydrodromous were observed, particularly when doses higher than 8-10ppm are tested. Overall, this research highlights the potential of Ch-AGNP for the development of newer control tools against young instar populations of malaria mosquitoes, also highlighting some risks concerned the employ of nanoparticles in aquatic environments.

  13. 三江源区水生生物状况及保护对策%Aquatic Organism Status and Protection Countermeasure Origin of Three Rivers

    Institute of Scientific and Technical Information of China (English)

    申志新; 简生龙

    2012-01-01

    Aquatic organism of Origin of Three Rivers, Qinghai, is equivalent to other terrestrial animals and water birds in status and indispensable part for maintaining biodiversity of Origin of Three Rivers. In particular, plateau fish, an important EQI indicator of Origin of Three Rivers, shows high values in economy, ecology, scientific research and human. Distribution of aquatic organism and protection to rare endangered species in Origin of Three Rivers are illustrated. Present problems and future challenges are analyzed and specific measures to protect species are put forward accordingly.%三江源区水生生物与其它陆生动物、水禽等具有同等重要的地位,是保持三江源区生物多样性不可或缺的重要组成部分,尤其高原鱼类是三江源生态环境质量状况的重要指示生物,具有很高的经济、生态、科研和人文价值。阐述了三江源区分布的水生生物基本状况及珍稀濒危物种的保护情况,分析了存在的问题和面临的挑战,并提出今后开展保护工作的具体措施。

  14. Aquatic Ecology Section

    International Nuclear Information System (INIS)

    Population studies were concerned with predicting long-term consequences of mortality imposed on animal populations by man's activities. These studies consisted of development of a generalized life cycle model and an empirical impingement model for use in impact analysis. Chemical effects studies were conducted on chlorine minimization; fouling by the Asiatic clam; identification of halogenated organics in cooling water; and effects of halogenated organics in cooling systems on aquatic organisms. Ecological transport studies were conducted on availability of sediment-bound 137Cs and 60Co to fish; 137Cs and 60Co in White Oak Lake fish; and chromium levels in fish from a lake chronically contaminated with chromates from cooling towers. Progress is also reported on the following: effects of irradiation on thermal tolerance of mosquito fish; toxicity of nickel to the developing eggs and larvae of carp; accumulation of selected heavy metals associated with fly ash; and environmental monitoring of aquatic ecosystems

  15. HUMUS CONTENT AND HUMUS FRACTIONS AFTER LONG-TERM SYSTEMIC MINERAL AND ORGANIC-MINERAL FERTILIZATION ON MOLLIC FLUVISOLS

    OpenAIRE

    Simeonova, N.; Todorova, S.

    2012-01-01

    The present work studies the effect of long-term systemic mineral and organic-mineral fertilization on the humus amount, humus type and humus fractions on Mollic fluvisols in Plovdiv region. Fertilizer norms are 1) N75P30K20; 2) N25P15K0 + organic; 3) N50P0K20 and 4) Standard. It was found that long-term systemic mineral and organic-mineral fertilization (forty-seven years) has a stabilized effect on humus content in studied soils. The systemic fertilization lead to a slight decrease of soil ...

  16. Biogeochemical characteristics of organic matter in the particulate and colloidal fractions downstream of the rio Negro and Solimoes rivers confluence

    OpenAIRE

    Gadel, François; Serve, Léon; Benedetti, Marc,; Leticia Cotrim Da Cunha,; Blazi, Jean-Louis

    2000-01-01

    International audience The analysis of organic matter in the rio Negro, rio Solimões and rio Amazonas focused on total organic carbon (TOC), as determined at two main sizes, the particulate form ($> 0.2 \\mu$m) and the colloidal form ($0.2 \\mu$m to 5000 dalton). These fractions were obtained by tangential ultrafiltration carried out on 50 l water samples. The total polysaccharide contents were determined by a colorimetric method, the main classes of organic compounds by pyrolysis and gas ch...

  17. Effects of antimony on aquatic organisms (Larva and embryo of Oryzias latipes, Moina macrocopa, Simocephalus mixtus, and Pseudokirchneriella subcapitata).

    Science.gov (United States)

    Nam, Sun-Hwa; Yang, Chang-Yong; An, Youn-Joo

    2009-05-01

    Antimony is widespread in aquatic environment. Trivalent forms of antimony are known to be more toxic than other chemical species of antimony. In the present study, antimony potassium tartrate (APT), the trivalent inorganic forms of antimony, was selected as a test antimony compound due to its high water solubility. The effects of antimony on Japanese medaka (Oryzias latipes), planktonic crustacea (Moina macrocopa and Simocephalus mixtus), and green algae (Pseudokirchneriella subcapitata) were evaluated. Larval survival and the embryonic development were measured for fish assay. APT was less toxic to larval medaka (24-h LC50, 261; 48-h LC50, 238 mg L(-1)). Simocephalus mixtus was killed by very low concentrations of APT (24-h LC50, 4.92 mg L(-1)), and antimony was also toxic to Moina macrocopa (24-h LC50, 12.83 mg L(-1)). Toxicities of APT to S. mixtus and Moina macrocopa were about 50 and 20 times more toxic to Oryzias latipes larvae, respectively, in terms of 24-h LC50 value. Growth inhibition of Pseudokirchneriella subcapitata was observed in the presence of APT (72-h EC50, 206 mg L(-1)). This study demonstrated that APT is more toxic to planktonic crustacea than fish and green algae, and planktonic crustacea appears a better indicator of antimony pollution in aquatic environment. PMID:19264343

  18. Organic waste compounds in streams: Occurrence and aquatic toxicity in different stream compartments, flow regimes, and land uses in southeast Wisconsin, 2006–9

    Science.gov (United States)

    Baldwin, Austin K.; Corsi, Steven R.; Richards, Kevin D.; Geis, Steven W.; Magruder, Christopher

    2013-01-01

    An assessment of organic chemicals and aquatic toxicity in streams located near Milwaukee, Wisconsin, indicated high potential for adverse impacts on aquatic organisms that could be related to organic waste compounds (OWCs). OWCs used in agriculture, industry, and households make their way into surface waters through runoff, leaking septic-conveyance systems, regulated and unregulated discharges, and combined sewage overflows, among other sources. Many of these compounds are toxic at elevated concentrations and (or) known to have endocrine-disrupting potential, and often they occur as complex mixtures. There is still much to be learned about the chronic exposure effects of these compounds on aquatic populations. During 2006–9, the U.S. Geological Survey, in cooperation with the Milwaukee Metropolitan Sewerage District (MMSD), conducted a study to determine the occurrence and potential toxicity of OWCs in different stream compartments and flow regimes for streams in the Milwaukee area. Samples were collected at 17 sites and analyzed for a suite of 69 OWCs. Three types of stream compartments were represented: water column, streambed pore water, and streambed sediment. Water-column samples were subdivided by flow regime into stormflow and base-flow samples. One or more compounds were detected in all 196 samples collected, and 64 of the 69 compounds were detected at least once. Base-flow samples had the lowest detection rates, with a median of 12 compounds detected per sample. Median detection rates for stormflow, pore-water, and sediment samples were more than double that of base-flow samples. Compounds with the highest detection rates include polycyclic aromatic hydrocarbons (PAHs), insecticides, herbicides, and dyes/pigments. Elevated occurrence and concentrations of some compounds were detected in samples from urban sites, as compared with more rural sites, especially during stormflow conditions. These include the PAHs and the domestic waste

  19. Laboratory evaluation of aqueous leaf extract of Tephrosia vogelii against larvae of Aedes albopictus (Diptera: Culicidae) and non-target aquatic organisms.

    Science.gov (United States)

    Li, Weisheng; Huang, Congling; Wang, Kun; Fu, Jiantao; Cheng, Dongmei; Zhang, Zhixiang

    2015-06-01

    Mosquito control using insecticides has been the most successful intervention known to reduce malaria prevalence or incidence. However, vector control is facing a threat due to the emergence of resistance to synthetic insecticides. Insecticides of botanical origin may serve as suitable alternative biocontrol techniques in the future. In this research, the leaf aqueous leachate of Tephrosia vogelii was evaluated for its toxicity against larvae of the most invasive mosquito worldwide, Aedes albopictus (Diptera: Culicidae), and toward adults of the water flea, Daphnia magna (Cladocera: Crustacea) and Oreochromis niloticus, two non-target aquatic organisms that share the same ecological niche of A. albopictus. The leaf aqueous leachate of T. vogelii was evaluated against fourth-instar larvae, non-blood fed 3-5 days old laboratory strains of A. albopictus under laboratory condition. In addition, the objective of the present work was to study the environmental safety evaluation for aquatic ecosystem. Mortality was then recorded after 7d exposure. The leaf aqueous leachate of T. vogelii showed high mosquitocidal activity against larvae of A. albopictus, with a LC50=1.18μg/mL. However, it had a remarkable acute toxicity also toward adults of the non-target arthropod D. magna, with a LC50=0.47μg/L and O. niloticus with a LC50=5.31μg/L. The present findings have important implications in the practical control of mosquito larvae in the aquatic ecosystem, as the medicinal plants studied are commonly available in large quantities. The extract could be used in stagnant water bodies for the control of mosquitoes acting as vector for many communicable diseases.

  20. Binding of pyrene to dissolved organic matters:fractionation and characterization

    Institute of Scientific and Technical Information of China (English)

    DAI Jing-yu; ZHOU Jiang-min; QIN Shu-ping

    2004-01-01

    Based on a modified Leenheer DOM fractionation scheme, fractionation of DOM from the paddy soil was conducted by using XAD-8 resin into hydrophobic bases(HOB), hydrophobic acids(HOA), acid-insoluble matter(AIM), hydrophobic neutrals(HON) and hydrophilic matter(HIM). In total carbon content of DOM, 35.32% were the HIM and only 0.73% the HOB. However, HOA and AIM altogether occupied 53.45%, while the HON fraction represented 10%. The sorption experiments were conducted to determine the sorption capcity of pyrene on unfractionated DOM and its fractions. Elemental analysis, 1H-NMR and FTIR spectra were carried out on unfractionated DOM and its fractions to examine the relationship between the structure of DOM and partition coefficients(Koc). The results showed that HON had a greater affinity for binding pyrene than other fractions. While HON was characterized by large long-chain alkylate (aliphatic structure). AIM exhibited relative higher Koc values than HOA and HIM, due to much aromatic structure in AIM, while the high content of carboxylic groups of HOA and HIM depressed their binding capacity. This study demonstrates HON is a key subcomponents of DOM in binding of pyrene, in other words, aliphalic structure in DOM play a important role in binding of pyrene.

  1. Thermal and mechanical stabilization process of the organic fraction of the municipal solid waste

    Energy Technology Data Exchange (ETDEWEB)

    Giudicianni, Paola, E-mail: giudicianni@irc.cnr.it [DIC-MAPI – Università degli Studi di Napoli Federico II (Italy); Bozza, Pio, E-mail: pi.bozza@studenti.unina.it [DIC-MAPI – Università degli Studi di Napoli Federico II (Italy); Sorrentino, Giancarlo, E-mail: g.sorrentino@unina.it [DIC-MAPI – Università degli Studi di Napoli Federico II (Italy); Ragucci, Raffaele, E-mail: ragucci@irc.cnr.it [Istituto di Ricerche sulla Combustione – C.N.R. Napoli (Italy)

    2015-10-15

    Graphical abstract: Display Omitted - Highlights: • A domestic scale prototype for the pre-treatment of OFMSW has been tested. • Two grinding techniques are compared and thermopress is used for the drying stage. • Increasing temperature up to 170 °C reduces energy consumption of the drying stage. • In the range 5–10 bar a reduction of 97% of the initial volume is obtained. • In most cases energy recovery from the dried waste matches energy consumption. - Abstract: In the present study a thermo-mechanical treatment for the disposal of the Organic Fraction of Municipal Solid Waste (OFMSW) at apartment or condominium scale is proposed. The process presents several advantages allowing to perform a significant volume and moisture reduction of the produced waste at domestic scale thus producing a material with an increased storability and improved characteristics (e.g. calorific value) that make it available for further alternative uses. The assessment of the applicability of the proposed waste pretreatment in a new scheme of waste management system requires several research steps involving different competences and application scales. In this context, a preliminary study is needed targeting to the evaluation and minimization of the energy consumption associated to the process. To this aim, in the present paper, two configurations of a domestic appliance prototype have been presented and the effect of some operating variables has been investigated in order to select the proper configuration and the best set of operating conditions capable to minimize the duration and the energy consumption of the process. The performances of the prototype have been also tested on three model mixtures representing a possible daily domestic waste and compared with an existing commercially available appliance. The results obtained show that a daily application of the process is feasible given the short treatment time required and the energy consumption comparable to the one of

  2. Thermal and mechanical stabilization process of the organic fraction of the municipal solid waste

    International Nuclear Information System (INIS)

    Graphical abstract: Display Omitted - Highlights: • A domestic scale prototype for the pre-treatment of OFMSW has been tested. • Two grinding techniques are compared and thermopress is used for the drying stage. • Increasing temperature up to 170 °C reduces energy consumption of the drying stage. • In the range 5–10 bar a reduction of 97% of the initial volume is obtained. • In most cases energy recovery from the dried waste matches energy consumption. - Abstract: In the present study a thermo-mechanical treatment for the disposal of the Organic Fraction of Municipal Solid Waste (OFMSW) at apartment or condominium scale is proposed. The process presents several advantages allowing to perform a significant volume and moisture reduction of the produced waste at domestic scale thus producing a material with an increased storability and improved characteristics (e.g. calorific value) that make it available for further alternative uses. The assessment of the applicability of the proposed waste pretreatment in a new scheme of waste management system requires several research steps involving different competences and application scales. In this context, a preliminary study is needed targeting to the evaluation and minimization of the energy consumption associated to the process. To this aim, in the present paper, two configurations of a domestic appliance prototype have been presented and the effect of some operating variables has been investigated in order to select the proper configuration and the best set of operating conditions capable to minimize the duration and the energy consumption of the process. The performances of the prototype have been also tested on three model mixtures representing a possible daily domestic waste and compared with an existing commercially available appliance. The results obtained show that a daily application of the process is feasible given the short treatment time required and the energy consumption comparable to the one of

  3. Evaluation of hormone-like activity of the dissolved organic matter fraction (DOM) of compost and digestate.

    Science.gov (United States)

    Scaglia, Barbara; Pognani, Michele; Adani, Fabrizio

    2015-05-01

    Biomasses are usually applied to soil for their agronomic properties (fertilization and amendment properties). Biomass can also have bio-stimulating effects on plants because of the presence of hormones and hormone-like molecules. Although compost has been the subject for studies of this aspect, no data have yet been reported on the extraction of this kind of molecule from digestate biomass. The aim of this work is to study the auxin- and gibberellin-like activity of pig slurry digestate in comparison with those of pruning and garden wastes compost's dissolved organic fraction (DOM). DOM (i.e., fractionorganic matter fractions readily available to microbial and plant metabolism. No gibberellin-like activities were found for either compost or digestate, whereas digestate showed auxin-like properties which were found to be located in its neutral hydrophobic (NHo) DOM fractions. Hormone activity was due principally to the presence of auxin coming from the anaerobic digestion of aromatic amino acids. PMID:25668284

  4. Assimilation efficiency in herbivorous aquatic organisms - the potential of the ratio method using 14C and biogenic silica as markers

    International Nuclear Information System (INIS)

    A method for measuring assimilation efficiencies based on the change in the Si: 14C ratio in food and feces is proposed. Since this indicator method uses biogenic silica as the inert substance, the method is restricted to aquatic herbivores that consume food containing it. The method has been demonstrated on adult female Calanus hyperboreus fed the diatom Thalassiosira anguste-lineata; assimilation efficiency decreases from 87.7 to 84.2% during a threefold increase in ingestion rate. The effect of errors in the estimate of Si:C ratios is slight when assimilation efficiency is high, but with decreasing values of assimilation efficiency, the sensitivity to errors in the estimates of silicon and carbon is increased

  5. Evaluating bio environmental effects of Bushehr Nuclear Power Plant on water and aquatic organism of Persian Gulf

    International Nuclear Information System (INIS)

    The operation of nuclear power plants is always subjected to emission of some radioactive materials in the form of gaseous, liquids and solids in the environment. The heat from condenser coolant discharged to the sea can have some adverse effects on biological systems as thermal pollution. In this project, the radiation and thermal effects on Bushehr Nuclear Power Plants on aquatic animals in Persian Gulf were studied. The mathematical models for atmospheric dispersion of pollutant and pathways of radioactive materials from air to sea water and from sea to animals and human bodies were considered. some environmental samples from Persian Gulf were measured for radioactivity using high-purity Ge/Li detectors and Gamma-spectroscopy. The results indicates that the erection of B usher Nuclear Power Plants and its operation in the normal operation can have no adverse effects on environment, and also its thermal pollution is of no importance due to low area for coolant discharges

  6. Trihalomethane, haloacetonitrile, and chloral hydrate formation potentials of organic carbon fractions from sub-tropical forest soils.

    Science.gov (United States)

    Zhang, Qian; Kuang, Wan-fang; Liu, Lu-ying; Li, Kexin; Wong, Kin-hang; Chow, Alex T; Wong, Po-keung

    2009-12-30

    Forest landscapes represent the major land-cover type for the watersheds of the East River, which is the source of water for 40 million people in South China. Forest soils with high levels of organic carbon are a potential terrestrial source of dissolved organic carbon (DOC) into the East River. DOC is of great concern, since it can form carcinogenic disinfection byproducts (DBPs) during drinking water treatment. In this study, soils from three altitudes (200, 450 and 900 m) in the Xiangtou Mountain Nature Reserve in South China, representing soils from evergreen moon forest, transitional evergreen broadleaf forest, and evergreen broadleaf forest, respectively, were evaluated for their potential contributions of DBP precursors into the East River. The water extractable organic carbon (WEOC) in three forest soils was physically and chemically fractionated into particulate organic carbon (1.2-0.45 microm), colloidal organic carbon (0.45-0.22 microm), and dissolved organic carbon (DOC) (soils were incubated at 15, 25 and 35 degrees C for 14d in darkness to examine the impact of temperature effects on the availability and characteristics of WEOC. The extraction study showed that the amount of WEOC was proportional to soil organic carbon content, of which about 1% was water extractable. Regardless of soil type, DOC and HPOA were the most reactive fractions in forming THMs, CHD, and HANs. Production of DOC and HPOA in WEOC increased over 14 d incubation as incubation temperature increased, but the temperature did not alter the distribution of physical and chemical fractions and their reactivity in DBP formation. Results suggest higher inputs of DOC and DBP precursors from forest watersheds into source water may result in a warmer environment. PMID:19695772

  7. Effect of biochar application and soil temperature on characteristics of organic matter associated with aggregate-size and density fractions

    Science.gov (United States)

    Kaiser, Michael; Grunwald, Dennis; Marhan, Sven; Poll, Christian; Bamminger, Chris; Ludwig, Bernard

    2016-04-01

    Potential increases in soil temperature due to climate change might result in intensified soil organic matter (SOM) decomposition and thus higher CO2 emissions. Management options to increase and stabilize SOM include the application of biochar. However, the effects of biochar amendments under elevated soil temperatures on SOM dynamics are largely unknown. The objective of this study was to analyze the effect of biochar application and elevated soil temperature on the amount and composition of OM associated with fractions of different turnover kinetics. Samples were taken from four treatments of the Hohenheim Climate Change Experiment with the factors temperature (ambient or elevated by 2.5 °C in 4 cm depth, six years before sampling) and biochar (control and 30 t / ha Miscanthus pyrolysis biochar, one year before sampling) in two depths (0 - 5 and 5 - 15 cm). Basal respiration and microbial biomass C were analyzed within an incubation experiment. Aggregate size-fractions were separated by wet-sieving and the free light, occluded light (oLF), and heavy fractions were isolated by density fractionation. All fractions were analyzed for organic C and δ13C as well as by infrared spectroscopy. Preliminary data suggest that biochar significantly increased basal respiration and that the microbial biomass C was significantly affected by elevated temperature. No biochar-C was found in the microbial biomass. Biochar and elevated temperature had only minor effects on the organic C associated with aggregate-size classes, although biochar was incorporated into all fractions already after one year of application. Biochar application significantly increased the organic C associated with oLF. In most samples affected by biochar, the proportion of C=O groups was significantly increased. The results suggest that already after one year, biochar-mineral interactions were formed leading to an aggregate occlusion of applied biochar. At least in the short-term, the effect of biochar on

  8. One-pot biogenic fabrication of silver nanocrystals using Quisqualis indica: Effectiveness on malaria and Zika virus mosquito vectors, and impact on non-target aquatic organisms.

    Science.gov (United States)

    Govindarajan, Marimuthu; Vijayan, Periasamy; Kadaikunnan, Shine; Alharbi, Naiyf S; Benelli, Giovanni

    2016-09-01

    Currently, mosquito vector control is facing a number of key challenges, including the rapid development of resistance to synthetic pesticides and the recent spread of aggressive arbovirus outbreaks. The biosynthesis of silver nanoparticles (AgNPs) is currently considered an environmental friendly alternative to the employ of pyrethroids, carbamates and microbial agents (e.g. Bacillus thuringiensis var. israelensis), since AgNPs are easy to produce, effective and stable in the aquatic environment. However, their biophysical features showed wide variations according to the botanical agent using for the green synthesis, outlining the importance of screening local floral resources used as reducing and stabilizing agents. In this study, we focused on the biophysical properties and the mosquitocidal action of Quisqualis indica-fabricated AgNPs. AgNPs were characterized using spectroscopic (UV, FTIR, XRD) and microscopic (AFM, SEM, TEM and EDX) techniques. AFM, SEM and TEM confirmed the synthesis of poly-dispersed AgNPs with spherical shape and size ranging from 1 to 30nm. XRD shed light on the crystalline structure of these AgNPs. The acute toxicity of Quisqualis indica extract and AgNPs was evaluated against malaria, arbovirus, and filariasis vectors, Anopheles stephensi, Aedes aegypti and Culex quinquefasciatus, as well as on three important non-target aquatic organisms. The Q. indica leaf extract showed moderate larvicidal effectiveness on Cx. quinquefasciatus (LC50=220.42), Ae. aegypti (LC50=203.63) and An. stephensi (LC50=185.98). Q. indica-fabricated AgNPs showed high toxicity against Cx. quinquefasciatus (LC50=14.63), Ae. aegypti (LC50=13.55) and An. stephensi (LC50=12.52), respectively. Notably, Q. indica-synthesized AgNPs were moderately toxic to non-target aquatic mosquito predators Anisops bouvieri (LC50=653.05μg/mL), Diplonychus indicus (LC50=860.94μg/mL) and Gambusia affinis (LC50=2183.16μg/mL), if compared to the targeted mosquitoes. Overall, the

  9. One-pot biogenic fabrication of silver nanocrystals using Quisqualis indica: Effectiveness on malaria and Zika virus mosquito vectors, and impact on non-target aquatic organisms.

    Science.gov (United States)

    Govindarajan, Marimuthu; Vijayan, Periasamy; Kadaikunnan, Shine; Alharbi, Naiyf S; Benelli, Giovanni

    2016-09-01

    Currently, mosquito vector control is facing a number of key challenges, including the rapid development of resistance to synthetic pesticides and the recent spread of aggressive arbovirus outbreaks. The biosynthesis of silver nanoparticles (AgNPs) is currently considered an environmental friendly alternative to the employ of pyrethroids, carbamates and microbial agents (e.g. Bacillus thuringiensis var. israelensis), since AgNPs are easy to produce, effective and stable in the aquatic environment. However, their biophysical features showed wide variations according to the botanical agent using for the green synthesis, outlining the importance of screening local floral resources used as reducing and stabilizing agents. In this study, we focused on the biophysical properties and the mosquitocidal action of Quisqualis indica-fabricated AgNPs. AgNPs were characterized using spectroscopic (UV, FTIR, XRD) and microscopic (AFM, SEM, TEM and EDX) techniques. AFM, SEM and TEM confirmed the synthesis of poly-dispersed AgNPs with spherical shape and size ranging from 1 to 30nm. XRD shed light on the crystalline structure of these AgNPs. The acute toxicity of Quisqualis indica extract and AgNPs was evaluated against malaria, arbovirus, and filariasis vectors, Anopheles stephensi, Aedes aegypti and Culex quinquefasciatus, as well as on three important non-target aquatic organisms. The Q. indica leaf extract showed moderate larvicidal effectiveness on Cx. quinquefasciatus (LC50=220.42), Ae. aegypti (LC50=203.63) and An. stephensi (LC50=185.98). Q. indica-fabricated AgNPs showed high toxicity against Cx. quinquefasciatus (LC50=14.63), Ae. aegypti (LC50=13.55) and An. stephensi (LC50=12.52), respectively. Notably, Q. indica-synthesized AgNPs were moderately toxic to non-target aquatic mosquito predators Anisops bouvieri (LC50=653.05μg/mL), Diplonychus indicus (LC50=860.94μg/mL) and Gambusia affinis (LC50=2183.16μg/mL), if compared to the targeted mosquitoes. Overall, the

  10. Does the antibiotic amoxicillin affect haemocyte parameters in non-target aquatic invertebrates? The clam Ruditapes philippinarum and the mussel Mytilus galloprovincialis as model organisms.

    Science.gov (United States)

    Matozzo, Valerio; Bertin, Valeria; Battistara, Margherita; Guidolin, Angelica; Masiero, Luciano; Marisa, Ilaria; Orsetti, Alessandro

    2016-08-01

    Amoxicillin (AMX) is one of the most widely used antibiotics worldwide, and its levels in aquatic ecosystems are expected to be detectable. At present, information concerning the toxic effects of AMX on non-target aquatic organisms, such as bivalves, is scarce. Consequently, in this study, we investigated for the first time the effects of AMX on the haemocyte parameters of two bivalve species, the clam Ruditapes philippinarum and the mussel Mytilus galloprovincialis, which share the same habitat in the Lagoon of Venice, in order to compare the relative sensitivity of the two species. The bivalves were exposed to 100, 200 and 400 μg AMX/L for 1, 3 and 7 days, and the effects on the total haemocyte count (THC), the diameter and volume of the haemocytes, haemocyte proliferation, lactate dehydrogenase (LDH) activity in cell-free haemolymph, the haemolymph pH, and the formation of micronuclei were evaluated. The actual concentrations of AMX in the seawater samples from the experimental tanks were also measured. Overall, the obtained results demonstrated that AMX affected slightly the haemocyte parameters of bivalves. In addition, no clear differences in terms of sensitivity to AMX exposure were recorded between the two bivalve species.

  11. Does the antibiotic amoxicillin affect haemocyte parameters in non-target aquatic invertebrates? The clam Ruditapes philippinarum and the mussel Mytilus galloprovincialis as model organisms.

    Science.gov (United States)

    Matozzo, Valerio; Bertin, Valeria; Battistara, Margherita; Guidolin, Angelica; Masiero, Luciano; Marisa, Ilaria; Orsetti, Alessandro

    2016-08-01

    Amoxicillin (AMX) is one of the most widely used antibiotics worldwide, and its levels in aquatic ecosystems are expected to be detectable. At present, information concerning the toxic effects of AMX on non-target aquatic organisms, such as bivalves, is scarce. Consequently, in this study, we investigated for the first time the effects of AMX on the haemocyte parameters of two bivalve species, the clam Ruditapes philippinarum and the mussel Mytilus galloprovincialis, which share the same habitat in the Lagoon of Venice, in order to compare the relative sensitivity of the two species. The bivalves were exposed to 100, 200 and 400 μg AMX/L for 1, 3 and 7 days, and the effects on the total haemocyte count (THC), the diameter and volume of the haemocytes, haemocyte proliferation, lactate dehydrogenase (LDH) activity in cell-free haemolymph, the haemolymph pH, and the formation of micronuclei were evaluated. The actual concentrations of AMX in the seawater samples from the experimental tanks were also measured. Overall, the obtained results demonstrated that AMX affected slightly the haemocyte parameters of bivalves. In addition, no clear differences in terms of sensitivity to AMX exposure were recorded between the two bivalve species. PMID:27219711

  12. Dissolved organic phosphorus and its bioavailable fraction in the Baltic Sea

    Science.gov (United States)

    Nausch, M.; Nausch, G.; Setzkorn, D.; Welz, Ä.

    2009-04-01

    In general, it is accepted that dissolved organic phosphorus (DOP) is besides dissolved inorganic phosphorus (DIP) a source for phosphorus nutrition of phyto- and bacterioplankton. If available, DIP is usually preferred to DOP. DOP becomes the most important source under DIP depleted conditions occurring in the Baltic Sea in summer. However, its contribution to nutrition and consequently its significance is very difficult to appraise because only the bioavailable fraction (BAP = bioavailable phosphorus) can be used by organisms. DOP comprises also inert compounds which persist over longer periods. Therefore, there is an urgent need to quantify the bioavailable DOP. In 2004 and 2005, DOP and BAP concentrations were detected in surface water at three stations in the central Baltic Sea from May until July. In June/July 2008 an intensive measuring campaign was performed throughout the whole Baltic Sea. DOP measurements were done from the entrance to the North Sea in the West until the innermost parts of the Gulf of Bothnia in the North and the Gulf of Finland in the East. BAP was determined at 14 stations in the central and northern parts. DOP was determined using the alkaline potassium peroxidisulphate oxidation method followed by the manual DIP determination. BAP has been detected in time course experiments using 0.8 µm filtered sea water containing free-living heterotrophic bacteria and amended with 7 µM ammonium chloride and 1mg l-1 D-(+) glucosemonohydrate to prevent nitrogen and carbon limitation and increase the phosphorus demand in bacteria. BAP is defined as that proportion of DOP which is used by bacteria and calculated as the difference of DOP concentrations at the beginning and the lowest concentrations during an incubation for 4-6 days. In 2004 and 2005, most DOP concentrations ranged between 0.18 and 0.32 µM, with a declining tendency from spring to summer probably due to elevated uptake compared to its release caused by higher temperatures and DIP

  13. Tritium in the aquatic environment

    International Nuclear Information System (INIS)

    Tritium is of environmental importance because it is released from nuclear facilities in relatively large quantities and because it has a half life of 12.26 y. Most of the tritium released into the atmosphere eventually reaches the aqueous environment, where it is rapidly taken up by aquatic organisms. This paper reviews the current literature on tritium in the aquatic environment. Conclusions from the review, which covered studies of algae, aquatic macrophytes, invertebrates, fish, and the food chain, were that aquatic organisms incorporate tritium into their tissue-free water very rapidly and reach concentrations near those of the external medium. The rate at which tritium from tritiated water is incorporated into the organic matter of cells is slower than the rate of its incorporation into the tissue-free water. If organisms consume tritiated food, incorporation of tritium into the organic matter is faster, and a higher tritium concentration is reached than when the organisms are exposed to only tritiated water alone. Incorporation of tritium bound to molecules into the organic matter depends on the chemical form of the ''carrier'' molecule. No evidence was found that biomagnification of tritium occurs at higher trophic levels. Radiation doses from tritium releases to large populations of humans will most likely come from the consumption of contaminated water rather than contaminated aquatic food products

  14. Tritium in the aquatic environment

    Energy Technology Data Exchange (ETDEWEB)

    Blaylock, B.G.; Hoffman, F.O.; Frank, M.L.

    1986-02-01

    Tritium is of environmental importance because it is released from nuclear facilities in relatively large quantities and because it has a half life of 12.26 y. Most of the tritium released into the atmosphere eventually reaches the aqueous environment, where it is rapidly taken up by aquatic organisms. This paper reviews the current literature on tritium in the aquatic environment. Conclusions from the review, which covered studies of algae, aquatic macrophytes, invertebrates, fish, and the food chain, were that aquatic organisms incorporate tritium into their tissue-free water very rapidly and reach concentrations near those of the external medium. The rate at which tritium from tritiated water is incorporated into the organic matter of cells is slower than the rate of its incorporation into the tissue-free water. If organisms consume tritiated food, incorporation of tritium into the organic matter is faster, and a higher tritium concentration is reached than when the organisms are exposed to only tritiated water alone. Incorporation of tritium bound to molecules into the organic matter depends on the chemical form of the ''carrier'' molecule. No evidence was found that biomagnification of tritium occurs at higher trophic levels. Radiation doses from tritium releases to large populations of humans will most likely come from the consumption of contaminated water rather than contaminated aquatic food products.

  15. Organic matter fractions in areas Oxisol under different management systems in Cerrado the State of Goiás, Brazil

    OpenAIRE

    Roni Fernandes Guareschi; Marcos Gervasio Pereira; Adriano Perin

    2013-01-01

    The objective of this study was to evaluate the physical and chemical fractions of soil organic matter (SOM), as well as perform the spectroscopic analysis in ultraviolet-visible humic acid in a Oxisol under no-tillage system (NTS) with different years of implementation, and compare them to areas of native cerrado and pasture. Was evaluated five areas namely: native cerrado (CE), planted pasture (PA) with Brachiaria decumbens; NTS with 3 (NTS 3) years of implementation; NTS with 15 years (NTS...

  16. 人工纳米材料对水生生物毒性的研究进展%Research progress on toxicity of manufactured nanomaterials to aquatic organisms

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    With rapid development of nanotechnology, manufactured nanomaterials (MNMs) have been widely used in biomedicine, aerospace, construction and many other fields in recent years. Widespread public concerns regarding the aquatic toxicity caused by MNMs have been aroused. In this article, with investigation of huge amount of related scientific research references, five aspects of toxic effects toward aquatic organisms by MNMs have been reviewed. Firstly, the effects on individual growth of aquatic organisms; secondly, the effects on the level of cell and tissue (including gill, liver and brain tissue);thirdly, the effects on the level of molecular and ge-netic (including DNA structure, mRNA and protein expression);fourthly, the effects and mechanism of reproduc-tive toxicity;lastly, the effects on other physiological functions such as photosynthesis and respiration. Meanwhile, potential side effects of MNMs on aquatic organisms’ food chain were evaluated. Furthermore, we prospected the toxicology development direction of MNMs in aquatic environment with an aim to guide the related studies for domestic scholars.%  近年来纳米技术发展迅速,人工纳米材料(MNMs)在生物医学、航空航天和建筑等领域中广泛应用。然而,随着大量MNMs不断进入水环境,人工纳米粒子对水生生物的毒性效应已引起人们的关注。通过调研人工纳米粒子对水生生物毒性的最新研究成果,重点对人工纳米粒子在5个方面对水生生物的毒性效应进行综述:1)对水生生物个体生长的毒性效应;2)对肝组织、鳃组织和脑组织等在组织细胞水平的毒性效应;3)在分子和基因水平上对DNA结构、mRNA和相关蛋白质表达的影响;4)对水生生物的生殖毒性效应和机制;5)对其他生理作用如光合作用和呼吸作用的毒性影响。同时还分析了MNMs对食物链的影响,进一步对MNMs在水体环境中的毒理学发展方向进行了展望,

  17. ISOLATING AND FRACTIONATING ORGANIC TOXICANTS IN SEDIMENTS: EVALUATION OF AN EXPERIMENTAL APPROACH

    Science.gov (United States)

    Most solid-phase sediment TIE techniques for organic chemicals have been focused on solid phase sorptive techniques, such as amending contaminated sediments with the carbonaceousresin, Ambersorb coconut charcoal, or XAD resin to reduce toxicity caused by organic contaminants. Cha...

  18. Proposed Release Guides to Protect Aquatic Biota

    Energy Technology Data Exchange (ETDEWEB)

    Marter, W.L.

    2001-03-28

    At the request of South Carolina Department of Health and Environmental Control (SCDHEC) and the Department of Energy (DOE), the Savannah River Laboratory was assigned the task of developing the release guides to protect aquatic biota. A review of aquatic radioecology literature by two leading experts in the field of radioecology concludes that exposure of aquatic biota at one rad per day or less will not produce detectable deleterious effects on aquatic organisms. On the basis of this report, DOE recommends the use of one rad per day as an interim dose standard to protect aquatic biota.

  19. Carbohydrates in size fractionated dissolved organic matter in a station of the Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Fernandes, L.; DeSouza, F.; Bhosle, N.B.

    whereas, UTCHO and UNS were relatively enriched in VHMW fraction. Concentrations of UDOC, UTCHO and UNS generally decreased with increasing water depth. The UNS-C accounted for 2.2 to 6.2% of UDOC and generally decreased with depth. The observed decrease...

  20. Characterization of the denitrifying fraction of phosphate accumulating organisms in biological phosphate removal

    DEFF Research Database (Denmark)

    Meinhold, Jens; Filipe, Carlos D.M.; Daigger, Glen T.;

    1999-01-01

    fractions of PAO are performed and compared. This study extends on previously reported results (Kerrn-Jespersen and Henze, 1993) in that the pH was controlled to around pH 7 to assure that phosphate precipitation was minimal, and in the measurement of PHB and PHV. With regards to the latter, the paper also...

  1. Viscosity and not biological mechanisms often controls the effects of temperature on ciliary activity and swimming velocity of small aquatic organisms

    DEFF Research Database (Denmark)

    Larsen, Poul Scheel; Riisgård, H. U.

    2009-01-01

    A number of studies have shown that temperature-dependent viscosity of the ambient water controls or strongly affects bio-mechanical activity such as beat frequency of water-pumping cilia in mussels and ascidians, swimming velocity of sperm cells, ciliates and small (micro- and meso-scale) aquatic...... is used to assess to what extent the response is purely physical/mechanical or biological. We argue that a power-law dependence of bio-mechanical activity (a) on kinematic viscosity (ν), i.e. a ~ ν^−m, should be applied to available data. Based on a general close matching of the response data to power...... organisms using cilia or small appendages for propulsion. Here we summarize results from the literature and from own studies on bio-mechanical activities in response to changing temperature or manipulated viscosity at constant temperature, both having the same change in kinematic viscosity. The survey...

  2. Monitoring of PAHs and alkylated PAHs in aquatic organisms after 1 month from the Solar I oil spill off the coast of Guimaras Island, Philippines.

    Science.gov (United States)

    Uno, Seiichi; Koyama, Jiro; Kokushi, Emiko; Monteclaro, Harold; Santander, Sheryll; Cheikyula, J Orkuma; Miki, Shizuho; Añasco, Nathaniel; Pahila, Ida G; Taberna, Hilario S; Matsuoka, Tatsuro

    2010-06-01

    Following the oil spill accident of the Solar I tanker in 2006 off the coast of Guimaras Island in the Philippines, polycyclic aromatic hydrocarbons (PAHs) and alkylated PAHs in some aquatic organisms were investigated at Luzaran in Guimaras and Taklong Islands, which were heavily polluted with spilled oil, immediately and 1 month after the accident. The concentrations of total PAHs were 11.9-52.3 ng/g dry weight in fish. Meanwhile, total PAH concentrations in shellfish were 38.0-3,102 ng/g dry weight in Luzaran and 128-236 ng/g dry weight in Taklong. Pyrene, phenanthrene, and fluoranthene were dominant in most fish and chrysene in all shellfish. Significantly higher concentrations of all alkylated homologs were detected in shellfish than in fish. These differences had two possible causes, that is, the differences between fish and shellfish could be attributed to the uptake routes and/or their metabolizing abilities.

  3. Dissipation of a commercial mixture of polyoxyethylene amine surfactants in aquatic outdoor microcosms: Effect of water depth and sediment organic carbon.

    Science.gov (United States)

    Rodriguez-Gil, Jose Luis; Lissemore, Linda; Solomon, Keith; Hanson, Mark

    2016-04-15

    This study optimized existing analytical approaches and characterized the effect of sediment total organic carbon (0.05-2.05% TOC), and water depth (15, 30, and 90cm) on the fate of MON 0818, a commercial mixture of polyoxyethylene amine surfactants (POEAs), in outdoor microcosms. Mixtures of POEAs are commonly used as adjuvants in commercial herbicide formulations containing glyphosate. Until recently, analytical methods sensitive enough to monitor environmental concentrations of POEAs in aquatic systems were not available. After optimizing recently developed analytical methods, we found that the combined use of accelerated solvent extraction (ASE) and liquid chromatography-tandem mass spectrometry provided a reliable approach for determining the concentration of sediment-adsorbed POEAs. The surfactant showed strong affinity for sediment materials, with low maximum recoveries by ASE of 52%. Under microcosm conditions, water depth or sediment characteristics did not significantly affect the water-column half-life of POEA, which ranged from 3.2 to 5.3h. Binding of POEAs to suspended solids was observed, which dissipated via one- or two-phase exponential decay; when two-phase decay occurred, fast phase half-life values ranged from 0.71 to 1.3h and slow-phase values ranged from 18 to 44h. Concentrations of POEA increased in sediment shortly after application and decreased over the study period with a half-life of 5.8 to 71d. The concentrations of POEAs in the sediment of the shallow (15cm) ponds dissipated following a two-phase exponential decay model with an initial fast-phase half-life of 1.1 to 8.9d and a slower second-phase half-life of 21d. Our results suggest that aquatic organisms are unlikely to be exposed to POEAs in aqueous phase for periods of more than a few hours following an over-water application, and that sediment is a significant sink for POEAs in aquatic systems. PMID:26845181

  4. Quantifying water flow within aquatic ecosystems using load cell sensors: a profile of currents experienced by coral reef organisms around Lizard Island, Great Barrier Reef, Australia.

    Science.gov (United States)

    Johansen, Jacob L

    2014-01-01

    Current velocity in aquatic environments has major implications for the diversity, abundance and ecology of aquatic organisms, but quantifying these currents has proven difficult. This study utilises a simple and inexpensive instrument (reef system around Lizard Island (Great Barrier Reef, Australia) at a spatial and temporal scale relevant to the ecology of individual benthos and fish. The instrument uses load-cell sensors to provide a correlation between sensor output and ambient current velocity of 99%. Each instrument is able to continuously record current velocities to >500 cms⁻¹ and wave frequency to >100 Hz over several weeks. Sensor data are registered and processed at 16 MHz and 10 bit resolution, with a measuring precision of 0.06±0.04%, and accuracy of 0.51±0.65% (mean ±S.D.). Each instrument is also pressure rated to 120 m and shear stresses ≤20 kNm⁻² allowing deployment in harsh environments. The instrument was deployed across 27 coral reef sites covering the crest (3 m), mid-slope (6 m) and deep-slope (9 m depth) of habitats directly exposed, oblique or sheltered from prevailing winds. Measurements demonstrate that currents over the reef slope and crest varies immensely depending on depth and exposure: currents differ up to 9-fold within habitats only separated by 3 m depth and 15-fold between exposed, oblique and sheltered habitats. Comparisons to ambient weather conditions reveal that currents around Lizard Island are largely wind driven. Zero to 22.5 knot winds correspond directly to currents of 0 to >82 cms⁻¹, while tidal currents rarely exceed 5.5 cms⁻¹. Rather, current velocity increases exponentially as a function of wave height (0 to 1.6 m) and frequency (0.54 to 0.20 Hz), emphasizing the enormous effect of wind and waves on organisms in these shallow coral reef habitats.

  5. Quantifying water flow within aquatic ecosystems using load cell sensors: a profile of currents experienced by coral reef organisms around Lizard Island, Great Barrier Reef, Australia.

    Directory of Open Access Journals (Sweden)

    Jacob L Johansen

    Full Text Available Current velocity in aquatic environments has major implications for the diversity, abundance and ecology of aquatic organisms, but quantifying these currents has proven difficult. This study utilises a simple and inexpensive instrument (500 cms⁻¹ and wave frequency to >100 Hz over several weeks. Sensor data are registered and processed at 16 MHz and 10 bit resolution, with a measuring precision of 0.06±0.04%, and accuracy of 0.51±0.65% (mean ±S.D.. Each instrument is also pressure rated to 120 m and shear stresses ≤20 kNm⁻² allowing deployment in harsh environments. The instrument was deployed across 27 coral reef sites covering the crest (3 m, mid-slope (6 m and deep-slope (9 m depth of habitats directly exposed, oblique or sheltered from prevailing winds. Measurements demonstrate that currents over the reef slope and crest varies immensely depending on depth and exposure: currents differ up to 9-fold within habitats only separated by 3 m depth and 15-fold between exposed, oblique and sheltered habitats. Comparisons to ambient weather conditions reveal that currents around Lizard Island are largely wind driven. Zero to 22.5 knot winds correspond directly to currents of 0 to >82 cms⁻¹, while tidal currents rarely exceed 5.5 cms⁻¹. Rather, current velocity increases exponentially as a function of wave height (0 to 1.6 m and frequency (0.54 to 0.20 Hz, emphasizing the enormous effect of wind and waves on organisms in these shallow coral reef habitats.

  6. Effects of Total Dissolved Solids on Aquatic Organisms: A Review of Literature and Recommendation for Salmonid Species

    OpenAIRE

    P. K. Weber-Scannell; Duffy, L K; Phyllis K. Weber-Scannell; Duffy, Lawrence K.

    2007-01-01

    Total dissolves solids (TDS) are naturally present in water or are the result of mining or some industrial treatment of water. TDS contain minerals and organic molecules that provide benefits such as nutrients or contaminants such as toxic metals and organic pollutants. Current regulations require the periodic monitoring of TDS, which is a measurement of inorganic salts, organic matter and other dissolved materials in water. Measurements of TDS do not differentiate among ions. The amount of T...

  7. Microbiological properties and oxidizable organic carbon fractions of an oxisol under coffee with split phosphorus applications and irrigation regimes

    Directory of Open Access Journals (Sweden)

    Adriana Rodolfo da Costa

    2013-02-01

    Full Text Available Phosphorus fertilization and irrigation increase coffee production, but little is known about the effect of these practices on soil organic matter and soil microbiota in the Cerrado. The objective of this study was to evaluate the microbiological and oxidizable organic carbon fractions of a dystrophic Red Latossol under coffee and split phosphorus (P applications and different irrigation regimes. The experiment was arranged in a randomized block design in a 3 x 2 factorial design with three split P applications (P1: 300 kg ha-1 P2O5, recommended for the crop year, of which two thirds were applied in September and the third part in December; P2: 600 kg ha-1 P2O5, applied at planting and then every two years, and P3: 1,800 kg ha-1 P2O5, the requirement for six years, applied at once at planting, two irrigation regimes (rainfed and year-round irrigation, with three replications. The layers 0-5 and 5-10 cm were sampled to determine microbial biomass carbon (MBC, basal respiration (BR, enzyme activity of acid phosphatase, the oxidizable organic carbon fractions (F1, F2, F3, and F4, and total organic carbon (TOC. The irrigation regimes increased the levels of MBC, microbial activity and acid phosphatase, TOC and oxidizable fractions of soil organic matter under coffee. In general, the form of dividing P had little influence on the soil microbial properties and OC. Only P3 under irrigation increased the levels of MBC and acid phosphatase activity.

  8. The influence of different soil management practices on auxin herbicide interactions with organic carbon in soil aggregate fractions

    Science.gov (United States)

    Schnitzler, Frauke; Haupt, Nadine; Burauel, Peter; Berns, Anne E.

    2010-05-01

    The influence of changing organic carbon contents in soils on the sorption and/or sequestration mechanisms of xenobiotics and their bioavailability are still not understood precisely. The present work discusses the turnover of a crop residue interacting with processes like mobilisation, binding and metabolism of an auxin herbicide in soil. The soil type was a haplic chernozem, available in three crop production regimes (low, normal and high) due to three types of fertilisation (none, mineral and mineral & organic) [1]. Two sets of experiments were conducted with undisturbed soil columns under field-like conditions. In the first set 14C-labelled maize straw was incorporated into the top soil and after three months incubation the herbicide benazolin was applied. In the second set the unlabelled maize straw was incorporated first, then 14C-labelled benazolin was added. Soil layers of 0-5 cm and 5-10 cm were fractionated in according to a soil aggregate fractionation procedure [2]. The content of organic carbon and the distribution of benazolin and its metabolites were detected in the gained soil fractions. In general, the specific organic carbon content and the specific 14C-activity of benazolin and its metabolites increased in the order from sand-sized though silt-sized to clay fraction due to increasing specific surface areas and sorption sites of the mineral particles. The highest sorption capacity of benazolin and its metabolites was detected in the soil layers of 0-5 cm with mineral fertilisation. In the 5-10 cm soil layers the binding capacity increased with increasing crop production. It was shown that more than half of the residual 14C-activity was not extractable. LC-MS/MS analysis of the extracts showed that the major components were benazolin and the relatively non-mobile thiazolin. The amount of benazolin in the extracts increased with increasing crop production, but decreased with increasing soil depth. These results indicate that maize straw amendment

  9. Determination of the biogenic secondary organic aerosol fraction in the boreal forest by AMS and NMR measurements

    Science.gov (United States)

    Finessi, E.; Decesari, S.; Paglione, M.; Giulianelli, L.; Carbone, C.; Gilardoni, S.; Fuzzi, S.; Saarikoski, S.; Raatikainen, T.; Hillamo, R.; Allan, J.; Mentel, Th. F.; Tiitta, P.; Laaksonen, A.; Petäjä, T.; Kulmala, M.; Worsnop, D. R.; Facchini, M. C.

    2011-08-01

    The study investigates the sources of fine organic aerosol (OA) in the boreal forest, based on measurements including both filter sampling (PM1) and online methods and carried out during a one-month campaign held in Hyytiälä, Finland, in spring 2007. Two aerosol mass spectrometers (Q-AMS, ToF-AMS) were employed to measure on-line air mass concentrations of major non-refractory aerosol species, while the water extracts of the filter samples were analyzed by nuclear magnetic resonance (NMR) spectroscopy for organic functional group characterization of the polar organic fraction of the aerosol. AMS and NMR spectra were processed separately by non-negative factorization algorithms, in order to apportion the main components underlying the submicrometer organic aerosol composition and depict them in terms of both mass fragmentation patterns and functional group compositions. The NMR results supported the AMS speciation of oxidized organic aerosol (OOA) into two main fractions, which could be generally labelled as more and less oxidized organics. The more oxidized component was characterized by a mass spectrum dominated by the m/z 44 peak, and in parallel by a NMR spectrum showing aromatic and aliphatic backbones highly substituted with oxygenated functional groups (carbonyls/carboxyls and hydroxyls). Such component, contributing on average 50 % of the OA mass throughout the observing period, was associated with pollution outbreaks from the Central Europe. The less oxidized component showed features consistent with less oxygenated aerosols and was enhanced in concomitance with air masses originating from the North-to-West sector, in agreement with previous investigations conducted at this site. NMR factor analysis was able to separate two distinct components under the less oxidized fraction of OA. One of these NMR-factors was associated to the formation of terrestrial biogenic secondary organic aerosol (BSOA), based on the comparison with spectral profiles obtained from

  10. Role of Inorganic and Organic Fractions in Animal Manure Compost in Lead Immobilization and Microbial Activity in Soil

    Directory of Open Access Journals (Sweden)

    Masahiko Katoh

    2016-01-01

    Full Text Available This study aimed to identify how the ratio of inorganic-to-organic components in animal manure compost (AMC affected both lead immobilization and microbial activity in lead-contaminated soil. When AMC containing 50% or more inorganic fraction with high phosphorous content was applied to contaminated soil, the amounts of water-soluble lead in it were suppressed by over 88% from the values in the soil without compost. The residual fraction under sequential extraction increased with the inorganic fraction in the AMC; however, in those AMCs, the levels of microbial enzyme activity were the same or less than those in the control soil. The application of AMC containing 25% inorganic fraction could alter the lead phases to be more insoluble while improving microbial enzyme activities; however, no suppression of the level of water-soluble lead existed during the first 30 days. These results indicate that compost containing an inorganic component of 50% or more with high phosphorus content is suitable for immobilizing lead; however, in the case where low precipitation is expected for a month, AMC containing 25% inorganic component could be used to both immobilize lead and restore microbial activity.

  11. Influence of hydrophobic/hydrophilic fractions of extracellular organic matters of Microcystis aeruginosa on ultrafiltration membrane fouling.

    Science.gov (United States)

    Zhou, Shiqing; Shao, Yisheng; Gao, Naiyun; Li, Lei; Deng, Jing; Tan, Chaoqun; Zhu, Mingqiu

    2014-02-01

    Fouling is a major obstacle to maintain the efficiency of ultrafiltration-based drinking water treatment process. Algal extracellular organic matters (EOMs) are currently considered as one of the major sources of membrane fouling. The objective of this study was to investigate the influence of different hydrophobic/hydrophilic fractions of EOM extracted from Microcystis aeruginosa on ultrafiltration membrane fouling at lab scale. The experimental data indicated that EOM exhibited similar flux decline trends on polyethersulfone (PES) and regenerated cellulose (RC) membranes but caused greater irreversible fouling on PES membrane than RC membrane due to its hydrophobic property. It was also observed that charged hydrophilic (CHPI) and neutral hydrophilic (NHPI) fractions caused greater flux decline over hydrophobic (HPO) and transphilic (TPI) fractions. For PES membrane, the order of the irreversible fouling potentials for the four fractions was HPO>TPI>CHPI>NHPI, while the irreversible fouling potentials of RC membrane were tiny and could be ignored. Fluorescence excitation-emission matrix (EEM) spectra and Fourier transform infrared (FTIR) spectra suggested that protein-like, polysaccharide-like and humic-like substances were the major components responsible for membrane fouling. The results also indicated that the irreversible fouling increased as the pH decreased. The addition of calcium to feed solutions led to more severe flux decline and irreversible fouling.

  12. How do changes in bulk soil organic carbon content affect carbon concentrations in individual soil particle fractions?

    Science.gov (United States)

    Yang, X M; Drury, C F; Reynolds, W D; Yang, J Y

    2016-01-01

    We test the common assumption that organic carbon (OC) storage occurs on sand-sized soil particles only after the OC storage capacity on silt- and clay-sized particles is saturated. Soil samples from a Brookston clay loam in Southwestern Ontario were analysed for the OC concentrations in bulk soil, and on the clay (<2 μm), silt (2-53 μm) and sand (53-2000 μm) particle size fractions. The OC concentrations in bulk soil ranged from 4.7 to 70.8 g C kg(-1) soil. The OC concentrations on all three particle size fractions were significantly related to the OC concentration of bulk soil. However, OC concentration increased slowly toward an apparent maximum on silt and clay, but this maximum was far greater than the maximum predicted by established C sequestration models. In addition, significant increases in OC associated with sand occurred when the bulk soil OC concentration exceeded 30 g C kg(-1), but this increase occurred when the OC concentration on silt + clay was still far below the predicted storage capacity for silt and clay fractions. Since the OC concentrations in all fractions of Brookston clay loam soil continued to increase with increasing C (bulk soil OC content) input, we concluded that the concept of OC storage capacity requires further investigation. PMID:27251365

  13. The content and UV-Vis absorbances of bog peat organic matter fractions (Divčivare, Serbia

    Directory of Open Access Journals (Sweden)

    Petrović Petar G.

    2015-01-01

    Full Text Available This paper presents peat soil organic matter characteristics at Divčibare Mountain (950 m a.s.l, mountain climate. Excessive wetting is caused by groundwater and floods, and plant litter originates from hydrophilic vegetation. An investigation was aimed at determining the correlation between organic matter characteristics (humification degree, stability and bioavailability with factors of soil formation and the most important physico-chemical characteristics of peat. Peat is mild acid and has a low base saturation. The content of organic matter is higher than 60% at depth of 40−80 cm, and higher than 40% at depths of 0−40 and 80−105 cm, respectively. Investigated peat had sapric characteristics. A content of humic acids in total organic matter indicates its unequal humification degree within profile, moderate to high at depth of 0−40 cm, low at 40−80-cm depth, and very low beneath 80 cm. A value of Ch/Cf ratio indicates high humus stability up to 80 cm where it has humate-type humus, while below 80 cm humus is the humatefulvate type. A low content of fractions separated with 0.1N cold H2SO4, and cold and hot water, points out a low bioavailability of organic matter through whole soil profile. UV-Vis indices indicate a low humification degree of humic acids (increased to 80-cm depth, and a very low humification degree of fulvic acids (variable, the highest at 60−80-cm depth. Overall results indicate that particle size of mineral fraction, soil reaction, and cation exchange capacity had no significant impact on organic matter characteristics. Soil moisture content, that is alterations of oxido-reductive conditions throughout soil profile had the crucial impact on peat organic matter characteristics.

  14. [Impacts of Land Use Changes on Soil Light Fraction and Particulate Organic Carbon and Nitrogen in Jinyun Mountain].

    Science.gov (United States)

    Lei, Li-guo; Jiang, Chang-sheng; Hao, Qing-ju

    2015-07-01

    Four land types including the subtropical evergreen broad-leaved forest, sloping farmland, orchard and abandoned land were selected to collect soil samples from 0 to 60 cm depth at the same altitude of sunny slope in the Jinyun Mountain in this study. Soil light fraction organic carbon and nitrogen ( LFOC and LFON), and particulate organic carbon and nitrogen (POC and PON) were determined and the distribution ratios and C/N ratios were calculated. The results showed that the contents of LFOC and LFON decreased significantly by 71. 42% and 38. 46% after the forest was changed into sloping farmland (P 0. 05), while the contents of LFOC and LFON increased significantly by 3. 77 and 1. 38 times after the sloping farmland was changed into abandoned land (P nitrogen accumulation; on the contrary, sloping farmland was easy to lose soil labile carbon and nitrogen. The LFOC and LFON distribution ratios were significantly reduced by 31. 20% and 30. 08%, respectively after the forest was changed into the sloping farmland, and increased by 18. 74% and 20. 33% respectively after the forest was changed into the orchard. Nevertheless, the distribution ratios of LFOC and LFON were changed little by converting the forest into the sloping farmland and orchard. The distribution ratios of LFOC, LFON, POC and PON all increased significantly after the farmland was abandoned (P soil organic carbon and nitrogen was enhanced after forest reclamation, while reduced after the sloping farmland was abandoned. The ratios of carbon to nitrogen in soil organic matter, light fraction organic matter and particulate organic matter were in the order of abandoned land (12. 93) > forest (8. 53) > orchard (7. 52) > sloping farmland (4. 40), abandoned land (16. 32) > forest (14. 29) > orchard (11. 32) > sloping farmland (7. 60), abandoned land (23. 41) > sloping farmland (13. 85 ) > forest (10. 30) > orchard (9. 64), which indicated that the degree of organic nitrogen mineralization was higher after

  15. The impact of a copper smelter on adjacent soil zinc and cadmium fractions and soil organic carbon

    Energy Technology Data Exchange (ETDEWEB)

    Liu Ling; Wu Longhua; Luo Yongming [Key Lab. of Soil Environment and Pollution Remediation, Chinese Academy of Sciences, NJ (China); Zhang Changbo [Shanghai Academy of Environmental Sciences, SH (China); Jiang Yugen; Qiu Xiya [Soils and Fertilisers Div., Fuyang City Agricultural Bureau, Hangzhou, ZJ (China)

    2010-07-15

    Purpose: We investigated the chemical fractions of Zn, Cd and Cu in soils collected from positions at different distances from a copper smelter and studied the relationships between distribution patterns of Zn, Cd and Cu, fractions and soil organic carbon (SOC), especially ''black carbon'' (BC), in contaminated soils. The relationships between soil particle size and concentrations of Zn and Cd in contaminated soil were also examined. Materials and methods: Soil samples were collected from field sites at different distances from the copper smelter, air-dried and passed through 0.25-mm and 0.149-mm nylon mesh sieves. The SOC and BC were determined. Aqua regia and sequentially extracted Zn, Cd and Cu fractions in soil and the different sizes of soil particles, and metal concentrations (Zn, Cd and Cu) in BC were also determined. Results and discussion: The soils were heavily contaminated by fly ash from the copper smelter. Concentrations of Zn, Cd and Cu in soil and SOC decreased with increasing distance from the smelter. Concentrations of Zn and Cd in the surface soil (0-15 cm) decreased from 27,017 to 892 mg kg{sup -1} and from 18.7 to 1.04 mg kg{sup -1}, respectively. Soil BC and concentrations of Zn, Cd and Cu in the BC fraction showed significant and positive relationships with the corresponding aqua regia metal concentrations in soil. Soil Zn and Cd occurred predominantly in the exchangeable and reducible fractions, but residual and oxidisable fractions of Cu that were not considered mobile or bioavailable were predominant (>60%). Concentrations of Zn and Cd in the soil particle size fractions tended to increase with decreasing particle size. Conclusions: The Cd and Zn and BC were all derived from the fly ash of the smelter. Concentrations of Zn and Cd and BC in the soil decreased significantly with increasing distance from the smelter. Zinc and Cd in contaminated soils increased as particle size decreased, and were mainly in highly available

  16. Calibration of nylon organic chemical integrative samplers and sentinel samplers for quantitative measurement of pulsed aquatic exposures.

    Science.gov (United States)

    Morrison, Shane A; Belden, Jason B

    2016-06-01

    Environmental exposures often occur through short, pulsed events; therefore, the ability to accurately measure these toxicologically-relevant concentrations is important. Three different integrative passive sampler configurations were evaluated under different flow and pulsed exposure conditions for the measurement of current-use pesticides (n=19), polyaromatic hydrocarbons (n=10), and personal care products (n=5) spanning a broad range of hydrophobicities (log Kow 1.5-7.6). Two modified POCIS-style samplers were investigated using macroporous nylon mesh membranes (35μm pores) and two different sorbent materials (i.e. Oasis HLB and Dowex Optipore L-493). A recently developed design, the Sentinel Sampler (ABS Materials), utilizing Osorb media enclosed within stainless steel mesh (145μm pores), was also investigated. Relatively high sampling rates (Rs) were achieved for all sampler configurations during the short eight-day exposure (4300-27mL/d). Under flow conditions, median Rs were approximately 5-10 times higher for POCIS-style samplers and 27 times higher for Sentinel Samplers, as compared to static conditions. The ability of samplers to rapidly measure hydrophobic contaminants may be a trade off with increased flow dependence. Analyte accumulation was integrative under pulsed and continuous exposures for POCIS-style samplers with mean difference between treatments of 11% and 33%; however, accumulation into Sentinel Samplers was more variable. Collectively, results show that reducing membrane limitations allows for rapid, integrative accumulation of a broad range of analytes even under pulsed exposures. As such, these sampler designs may be suitable for monitoring environmental substances that have short aquatic half-lives. PMID:27139214

  17. Evaluation of hormone-like activity of the dissolved organic matter fraction (DOM) of compost and digestate.

    Science.gov (United States)

    Scaglia, Barbara; Pognani, Michele; Adani, Fabrizio

    2015-05-01

    Biomasses are usually applied to soil for their agronomic properties (fertilization and amendment properties). Biomass can also have bio-stimulating effects on plants because of the presence of hormones and hormone-like molecules. Although compost has been the subject for studies of this aspect, no data have yet been reported on the extraction of this kind of molecule from digestate biomass. The aim of this work is to study the auxin- and gibberellin-like activity of pig slurry digestate in comparison with those of pruning and garden wastes compost's dissolved organic fraction (DOM). DOM (i.e., fractioncompost or digestate, whereas digestate showed auxin-like properties which were found to be located in its neutral hydrophobic (NHo) DOM fractions. Hormone activity was due principally to the presence of auxin coming from the anaerobic digestion of aromatic amino acids.

  18. How do changes in bulk soil organic carbon content affect carbon concentrations in individual soil particle fractions?

    Science.gov (United States)

    Yang, X. M.; Drury, C. F.; Reynolds, W. D.; Yang, J. Y.

    2016-06-01

    We test the common assumption that organic carbon (OC) storage occurs on sand-sized soil particles only after the OC storage capacity on silt- and clay-sized particles is saturated. Soil samples from a Brookston clay loam in Southwestern Ontario were analysed for the OC concentrations in bulk soil, and on the clay (clay, but this maximum was far greater than the maximum predicted by established C sequestration models. In addition, significant increases in OC associated with sand occurred when the bulk soil OC concentration exceeded 30 g C kg‑1, but this increase occurred when the OC concentration on silt + clay was still far below the predicted storage capacity for silt and clay fractions. Since the OC concentrations in all fractions of Brookston clay loam soil continued to increase with increasing C (bulk soil OC content) input, we concluded that the concept of OC storage capacity requires further investigation.

  19. Determining organic carbon distributions in soil particle size fractions as a precondition of lateral carbon transport modeling at large scales

    Science.gov (United States)

    Schindewolf, Marcus; Seher, Wiebke; Pfeffer, Eduard; Schultze, Nico; Amorim, Ricardo S. S.; Schmidt, Jürgen

    2016-04-01

    The erosional transport of organic carbon has an effect on the global carbon budget, however, it is uncertain, whether erosion is a sink or a source for carbon in the atmosphere. Continuous erosion leads to a massive loss of top soils including the loss of organic carbon historically accumulated in the soil humus fraction. The colluvial organic carbon could be protected from further degradation depending on the depth of the colluvial cover and local decomposing conditions. Another part of eroded soils and organic carbon will enter surface water bodies and might be transported over long distances. The selective nature of soil erosion results in a preferential transport of fine particles while less carbonic larger particles remain on site. Consequently organic carbon is enriched in the eroded sediment compared to the origin soil. As a precondition of process based lateral carbon flux modeling, carbon distribution on soil particle size fractions has to be known. In this regard the present study refers to the determination of organic carbon contents on soil particle size separates by a combined sieve-sedimentation method for different tropical and temperate soils Our results suggest high influences of parent material and climatic conditions on carbon distribution on soil particle separates. By applying these results in erosion modeling a test slope was simulated with the EROSION 2D simulation software covering certain land use and soil management scenarios referring to different rainfall events. These simulations allow first insights on carbon loss and depletion on sediment delivery areas as well as carbon gains and enrichments on deposition areas on the landscape scale and could be used as a step forward in landscape scaled carbon redistribution modeling.

  20. Radioactivity in the Canadian aquatic environment

    International Nuclear Information System (INIS)

    Sources of radionuclides arising from natural anthropogenic processes as well as technologically enhanced natural radiation are discussed. Transport, distribution and behaviour of these radionuclides in aquatic systems are influenced by physical, chemical, biological and geological processes and conditions in freshwater and marine environments. Dosimetry of aquatic organisms, as well as various methods of measuring dose rate are presented. Effects of ionizing radiation (acute and chronic exposure) on aquatic organisms, populations and ecosystems are reviewed. This review covers the entire spectrum of the aquatic environment. Results of many studies are summarized. 300+ refs

  1. Flying high: on the airborne dispersal of aquatic organisms as illustrated by the distribution histories of the gastropod genera Tryonia and Planorbarius

    OpenAIRE

    Wesselingh, F.P.; Cadée, G.C.; Renema, W.

    1999-01-01

    The actual and fossil distribution patterns of the aquatic gastropod genera Tryonia and Planorbarius indicate that avian dispersal was an important dispersal mechanism in the geological past. Combining the distribution histories of these genera with ecological data on modern relatives provides insights into the process of dispersal of aquatic taxa in general. Avian dispersal of aquatic taxa is facilitated by a variety of factors, including mass occurrence in resting/foraging places of migrati...

  2. Municipal solid waste organic fraction management: A multicriteria analysis for societal performance

    OpenAIRE

    Fevre-Gautier, Anne-Lise; Wavrer, Philippe; Michel, Pascale

    2012-01-01

    The results presented here derive from the work conducted for an ongoing two-year research project funded by the French Ministry of Environment and started in 2011. In 2007, 14% of French municipal waste collected by public services were going through organic valorization, when more than 60% of municipal residual waste (representing 153 kg of household residual waste per inhabitant and per year) could still undergo an organic treatment. To fulfill European and national commitments though, Fre...

  3. Highly efficient organosolv fractionation of cornstalk into cellulose and lignin in organic acids.

    Science.gov (United States)

    Shui, Tao; Feng, Shanghuan; Yuan, Zhongshun; Kuboki, Takashi; Xu, Chunbao Charles

    2016-10-01

    In this study, effects of fractionation solvents, catalysts, temperatures and residence time on yields, purity and chemical composition of the products were investigated at the solid/solvent ratio of 1:5 (g/g). It was revealed that mixture of acetic acid/formic acid/water at the ratio of 3:6:1 (v/v/v) resulted in crude cellulose and lignin products of relatively high purity. The use of HCl catalyst contributed to a high crude cellulose yield, while H2SO4 showed an adverse effect on cellulose yield. However, both of these acidic catalysts contributed to much lower hemicellulose contents in the resulted crude cellulose products compared with those obtained without a catalyst. Fractionation at 90°C for 180min in mixed solvents of acetic acid/formic acid/water (3:6:1, v/v/v) with or without catalyst produced crude cellulose with very low residual lignin contents (<4%). PMID:27450125

  4. Soil Organic Carbon and Its Fractions Across Vegetation Types: Effects of Soil Mineral Surface Area and Microaggregates

    Institute of Scientific and Technical Information of China (English)

    WU Qing-Biao; WANG Xiao-Ke; OUYANG Zhi-Yun

    2009-01-01

    Soil organic carbon (SOC) can act as a sink or source of atmospheric carbon dioxide;therefore,it is important to understand the amount and composition of SOC in terrestrial ecosystems,the spatial variation in SOC,and the underlying mechanisms that stabilize SOC.In this study,density fractionation and acid hydrolysis were used to assess the spatial variation in SOC,the heavy fraction of organic carbon (HFOC),and the resistant organic carbon (ROC) in soils of the southern Hulun Buir region,northeastern China,and to identify the major factors that contribute to this variation.The results showed that as the contents of clay and silt particles (0-50 μm) increased,both methylene blue (MB) adsorption by soil minerals and microaggregate contents increased in the 0-20 and 20-40 cm soil layers (P<0.05).Although varying with vegetation types,SOC,HFOC,and ROC contents increased significantly with the content of clay and silt particles,MB adsorption by soil minerals,and microaggregate content (P<0.05),suggesting that soil texture,the MB adsorption by soil minerals,and microaggregate abundance might be important factors influencing the spatial heterogeneity of carbon contents in soils of the southern Hulun Buir region.

  5. Optimization of the fractionated irradiation scheme considering physical doses to tumor and organ at risk based on dose–volume histograms

    Energy Technology Data Exchange (ETDEWEB)

    Sugano, Yasutaka [Graduate School of Health Sciences, Hokkaido University, Kita-12, Nishi-5, Kita-ku, Sapporo, Hokkaido 060-0812 (Japan); Mizuta, Masahiro [Laboratory of Advanced Data Science, Information Initiative Center, Hokkaido University, Kita-11, Nishi-5, Kita-ku, Sapporo, Hokkaido 060-0811 (Japan); Takao, Seishin; Shirato, Hiroki; Sutherland, Kenneth L. [Department of Radiation Medicine, Graduate School of Medicine, Hokkaido University, Kita-15, Nishi-5, Kita-ku, Sapporo, Hokkaido 060-8638 (Japan); Date, Hiroyuki, E-mail: date@hs.hokudai.ac.jp [Faculty of Health Sciences, Hokkaido University, Kita-12, Nishi-5, Kita-ku, Sapporo, Hokkaido 060-0812 (Japan)

    2015-11-15

    Purpose: Radiotherapy of solid tumors has been performed with various fractionation regimens such as multi- and hypofractionations. However, the ability to optimize the fractionation regimen considering the physical dose distribution remains insufficient. This study aims to optimize the fractionation regimen, in which the authors propose a graphical method for selecting the optimal number of fractions (n) and dose per fraction (d) based on dose–volume histograms for tumor and normal tissues of organs around the tumor. Methods: Modified linear-quadratic models were employed to estimate the radiation effects on the tumor and an organ at risk (OAR), where the repopulation of the tumor cells and the linearity of the dose-response curve in the high dose range of the surviving fraction were considered. The minimization problem for the damage effect on the OAR was solved under the constraint that the radiation effect on the tumor is fixed by a graphical method. Here, the damage effect on the OAR was estimated based on the dose–volume histogram. Results: It was found that the optimization of fractionation scheme incorporating the dose–volume histogram is possible by employing appropriate cell surviving models. The graphical method considering the repopulation of tumor cells and a rectilinear response in the high dose range enables them to derive the optimal number of fractions and dose per fraction. For example, in the treatment of prostate cancer, the optimal fractionation was suggested to lie in the range of 8–32 fractions with a daily dose of 2.2–6.3 Gy. Conclusions: It is possible to optimize the number of fractions and dose per fraction based on the physical dose distribution (i.e., dose–volume histogram) by the graphical method considering the effects on tumor and OARs around the tumor. This method may stipulate a new guideline to optimize the fractionation regimen for physics-guided fractionation.

  6. ORGANIC CARBON CONTENTS AND STOCKS IN PARTICLE SIZE FRACTIONS OF A TYPIC HAPLUDOX FERTILIZED WITH PIG SLURRY AND SOLUBLE FERTILIZER

    OpenAIRE

    Maria Sueli Heberle Mafra; Paulo Cezar Cassol; Jackson Adriano Albuquerque; Marco André Grohskopf; Andreia Patrícia Andrade; Luiz Paulo Rauber; Augusto Friederichs

    2015-01-01

    The use of pig slurry (PS) as fertilizer can affect the soil quality and increase total stocks of soil organic carbon (TOC). However, the effects of PS on TOC amount and forms in the soil are not fully understood, particularly in areas under no-tillage (NT). The purpose of this study was to determine TOC contents and stocks in the particulate (POC) and mineral-associated C fractions (MAC) of an Oxisol after nine years of maize-oat rotation under NT, with annual applications of PS, soluble fer...

  7. The nature of organic carbon in density-fractionated sediments in the Sacramento-San Joaquin River Delta (California)

    Science.gov (United States)

    Wakeham, S. G.; Canuel, E. A.

    2016-02-01

    Rivers are the primary means by which sediments and carbon are transported from the terrestrial biosphere to the oceans but gaps remain in our understanding of carbon associations from source to sink. Bed sediments from the Sacramento-San Joaquin River Delta (CA) were fractionated according to density and analyzed for sediment mass distribution, elemental (C and N) composition, mineral surface area, and stable carbon and radiocarbon isotope compositions of organic carbon (OC) and fatty acids to evaluate the nature of organic carbon in river sediments. OC was unevenly distributed among density fractions. Mass and OC were in general concentrated in mesodensity (1.6-2.0 and 2.0-2.5 g cm-3) fractions, comprising 84.0 ± 1.3 % of total sediment mass and 80.8 ± 13.3 % of total OC (TOC). Low-density ( 2.5 g cm-3) organic-poor, mineral-rich material made-up 13.7 ± 1.4 % of sediment mass and 2.0 ± 0.9 % of TOC. Stable carbon isotope compositions of sedimentary OC were relatively uniform across bulk and density fractions (δ13C -27.4 ± 0.5 ‰). Radiocarbon content varied from Δ14C values of -382 (radiocarbon age 3800 yr BP) to +94 ‰ (modern) indicating a mix of young and old OC. Fatty acids were used to further constrain the origins of sedimentary OC. Short-chain n-C14-n-C18 fatty acids of algal origin were depleted in 13C (δ13C -37.5 to -35.2 ‰) but were enriched in 14C (Δ14C > 0) compared to long-chain n-C24-n-C28 acids of vascular plant origins with higher δ13C (-33.0 to -31.0 ‰) but variable Δ14C values (-180 and 61 ‰). These data demonstrate the potentially complex source and age distributions found within river sediments and provide insights about sediment and organic matter supply to the Delta.

  8. Experimental insights into the importance of aquatic bacterial community composition to the degradation of dissolved organic matter

    DEFF Research Database (Denmark)

    Logue, J.B.; Stedmon, Colin; Kellerman, A.M.;

    2016-01-01

    Bacteria play a central role in the cycling of carbon, yet our understanding of the relationship between the taxonomic composition and the degradation of dissolved organic matter (DOM) is still poor. In this experimental study, we were able to demonstrate a direct link between community composition...

  9. Leveraging existing data for prioritization of the ecological risks of human and veterinary pharmaceuticals to aquatic organisms

    Science.gov (United States)

    Medicinal innovation has lead to the discovery and use of thousands of human and veterinary drugs. With this comes the potential for unintended effects on non-target organisms exposed to pharmaceuticals inevitably entering the environment. The impracticality of generating whole-o...

  10. Effect of the three-dimensional organization of liver cells on the biogenesis of the γ-glutamyltransferase fraction pattern.

    Science.gov (United States)

    Corti, Alessandro; Fierabracci, Vanna; Caponi, Laura; Paolicchi, Aldo; Lorenzini, Evelina; Campani, Daniela; Belcastro, Eugenia; Franzini, Maria

    2016-07-01

    Context Four gamma-glutamyltransferase (GGT) fractions with different molecular weights (big-, medium-, small- and free-GGT) are detectable in human plasma. Objective Verify if liver cells can release all four GGT fractions and if the spatial cell organization influences their release. Methods Hepatoma (HepG2) and melanoma (Me665/2/60) cells were cultured as monolayers or spheroids. GGT released in culture media was analysed by gel-filtration chromatography. Results HepG2 and Me665/2/60 monolayers released the b-GGT fraction, while significative levels of s-GGT and f-GGT were detectable only in media of HepG2-spheroids. Bile acids alone or in combination with papain promoted the conversion of b-GGT in s-GGT or f-GGT, respectively. Conclusions GGT is usually released as b-GGT, while s-GGT and f-GGT are likely to be produced in the liver extracellular environment by the combined action of bile acids and proteases. PMID:27027926

  11. Relative importance of the humic and fulvic fractions of natural organic matter in the aggregation and deposition of silver nanoparticles.

    Science.gov (United States)

    Furman, Olha; Usenko, Sascha; Lau, Boris L T

    2013-02-01

    As engineered nanoparticles (NPs) are increasingly used, their entry into the environment has become an important topic for water sustainability. Recent investigations point to the critical role of natural organic matter (NOM) in altering the persistence of NPs by complexing with their surfaces. The NP-NOM complex, in turn, is the new entity that may potentially influence subsequent fate of NPs. To understand the relative impact of humic (HA) and fulvic fraction of NOM on the stability and mobility of silver nanoparticles (AgNPs), a combination of dynamic light scattering and quartz crystal microgravimetry with dissipation monitoring was used. In the absence of unbound NOM, (1) surface modification on either AgNP or silica substrate by different NOM fractions could lead to substantial changes in the extent and kinetics of AgNP aggregation and deposition, and (2) HA has a greater capability to enhance the transport of AgNPs by reducing their aggregation and deposition. With unbound NOM, HA seems to compete more successfully for binding sites on the substrate under electrostatically favorable conditions and formed a steric layer to prevent subsequent deposition of AgNPs. These findings highlighted the importance of NOM fraction in the overall environmental partitioning of AgNPs. PMID:23298221

  12. Characterization of plant-derived carbon and phosphorus in lakes by sequential fractionation and NMR spectroscopy.

    Science.gov (United States)

    Liu, Shasha; Zhu, Yuanrong; Wu, Fengchang; Meng, Wei; He, Zhongqi; Giesy, John P

    2016-10-01

    Although debris from aquatic macrophytes is one of the most important endogenous sources of organic matter (OM) and nutrients in lakes, its biogeochemical cycling and contribution to internal load of nutrients in eutrophic lakes are still poorly understood. In this study, sequential fractionation by H2O, 0.1M NaOH and 1.0M HCl, combined with (13)C and (31)P NMR spectroscopy, was developed and used to characterize organic carbon (C) and phosphorus (P) in six aquatic plants collected from Tai Lake (Ch: Taihu), China. Organic matter, determined by total organic carbon (TOC), was unequally distributed in H2O (21.2%), NaOH (29.9%), HCl (3.5%) and residual (45.3%) fractions. For P in debris of aquatic plants, 53.3% was extracted by H2O, 31.9% by NaOH, and 11% by HCl, with 3.8% in residual fractions. Predominant OM components extracted by H2O and NaOH were carbohydrates, proteins and aliphatic acids. Inorganic P (Pi) was the primary form of P in H2O fractions, whereas organic P (Po) was the primary form of P in NaOH fractions. The subsequent HCl fractions extracted fewer species of C and P. Some non-extractable carbohydrates, aromatics and metal phytate compounds remained in residual fractions. Based on sequential extraction and NMR analysis, it was proposed that those forms of C (54.7% of TOC) and P (96.2% of TP) in H2O, NaOH and HCl fractions are potentially released to overlying water as labile components, while those in residues are stable and likely preserved in sediments of lakes. These results will be helpful in understanding internal loading of nutrients from debris of aquatic macrophytes and their recycling in lakes. PMID:27282495

  13. Sediment Surface Areas, Organic Content, and Metal Fractionation of Point Mugu Sediments

    Science.gov (United States)

    Becerra, C. A.; Wong, N.; Khachikian, C. S.

    2002-12-01

    Point Mugu contains one of the largest coastal wetlands ecosystems in California, which includes a Naval Air station, several sewage oxidation ponds and a partly dredged lagoon. Remediation efforts include investigating the feasibility of using the present sewage pond sludge to restore a dredged area in the lagoon. A problem with this approach is the potential release and subsequent environmental impact of the toxic substances from the sludge. Contaminants may become unavailable once sorbed onto particles. In general, this process is a direct function of surface area and organic carbon sorbed onto the sediment. The goal of the current investigation is to provide insight into the biological availability of a suite of metal contaminants in Pt. Mugu marsh sediments by studying changes in the physical and chemical properties of the sediments at horizontal and vertical spatial scales. The surface area and organic carbon for eight cores were measured as well as the first three sequential extraction of a host of metals. We have found that a direct correlation exists between surface area and the organic content of sediments as a function of depth. Surface area and the amount of organic carbon decreases with depth, which could result in higher availability of metals with increasing depth into the sediments.

  14. Influence of nonlinear sorption kinetics on the slow-desorbing organic contaminant fraction in soil

    NARCIS (Netherlands)

    Schlebaum, W.; Schraa, G.; Riemsdijk, van W.H.

    1999-01-01

    Release rates of hydrophobic organic compounds (HOCs) from the soil matrix influence the availability of HOCs in soils or sediments for microbial degradation or removal by physical means (e.g., soil washing or soil venting). In this study it was shown that the initial contaminant concentration influ

  15. Anaerobic digestion of organic fraction of municipal solid waste combining two pretreatment modalities, high temperature microwave and hydrogen peroxide

    International Nuclear Information System (INIS)

    Highlights: ► Microwave and H2O2 pretreatment were studied to enhance anaerobic digestion of organic waste. ► The whole waste pretreated at 115 °C or 145 °C had the highest biogas production. ► Biogas production of the whole waste decreased at 175 °C due to formation of refractory compounds. ► Pretreatment to 145 °C and 175 °C were the best when considering only the free liquid fraction. ► H2O2 pretreatment had a lag phase and the biogas production was not higher than MW pretreated samples. - Abstract: In order to enhance anaerobic digestion (AD) of the organic fraction of municipal solid waste (OFMSW), pretreatment combining two modalities, microwave (MW) heating in presence or absence of hydrogen peroxide (H2O2) were investigated. The main pretreatment variables affecting the characteristics of the OFMSW were temperature (T) via MW irradiation and supplemental water additions of 20% and 30% (SWA20 and SW30). Subsequently, the focus of this study was to evaluate mesophilic batch AD performance in terms of biogas production, as well as changes in the characteristics of the OFMSW post digestion. A high MW induced temperature range (115–175 °C) was applied, using sealed vessels and a bench scale MW unit equipped with temperature and pressure controls. Biochemical methane potential (BMP) tests were conducted on the whole OFMSW as well as the liquid fractions. The whole OFMSW pretreated at 115 °C and 145 °C showed 4–7% improvement in biogas production over untreated OFMSW (control). When pretreated at 175 °C, biogas production decreased due to formation of refractory compounds, inhibiting the digestion. For the liquid fraction of OFMSW, the effect of pretreatment on the cumulative biogas production (CBP) was more pronounced for SWA20 at 145 °C, with a 26% increase in biogas production after 8 days of digestion, compared to the control. When considering the increased substrate availability in the liquid fraction after MW pretreatment, a 78

  16. Characterization of plant-derived carbon and phosphorus in lakes by sequential fractionation and NMR spectroscopy

    Science.gov (United States)

    Although debris from aquatic macrophytes is one of the most important endogenous sources of organic matter (OM) and nutrients in lakes, its biogeochemical cycling and contribution to internal load of nutrients in eutrophic lakes are still poorly understood. In this study, sequential fractionation by...

  17. Tetrodotoxin – Distribution and Accumulation in Aquatic Organisms, and Cases of Human Intoxication

    Directory of Open Access Journals (Sweden)

    Osamu Arakawa

    2008-05-01

    Full Text Available Many pufferfish of the family Tetraodontidae possess a potent neurotoxin, tetrodotoxin (TTX. In marine pufferfish species, toxicity is generally high in the liver and ovary, whereas in brackish water and freshwater species, toxicity is higher in the skin. In 1964, the toxin of the California newt was identified as TTX as well, and since then TTX has been detected in a variety of other organisms. TTX is produced primarily by marine bacteria, and pufferfish accumulate TTX via the food chain that begins with these bacteria. Consequently, pufferfish become non-toxic when they are fed TTX-free diets in an environment in which the invasion of TTX-bearing organisms is completely shut off. Although some researchers claim that the TTX of amphibians is endogenous, we believe that it also has an exogenous origin, i.e., from organisms consumed as food. TTX-bearing animals are equipped with a high tolerance to TTX, and thus retain or accumulate TTX possibly as a biologic defense substance. There have been many cases of human intoxication due to the ingestion of TTX-bearing pufferfish, mainly in Japan, China, and Taiwan, and several victims have died. Several cases of TTX intoxication due to the ingestion of small gastropods, including some lethal cases, were recently reported in China and Taiwan, revealing a serious public health issue.

  18. Effects of Total Dissolved Solids on Aquatic Organisms: A Review of Literature and Recommendation for Salmonid Species

    Directory of Open Access Journals (Sweden)

    P. K. Weber-Scannell

    2007-01-01

    Full Text Available Total dissolves solids (TDS are naturally present in water or are the result of mining or some industrial treatment of water. TDS contain minerals and organic molecules that provide benefits such as nutrients or contaminants such as toxic metals and organic pollutants. Current regulations require the periodic monitoring of TDS, which is a measurement of inorganic salts, organic matter and other dissolved materials in water. Measurements of TDS do not differentiate among ions. The amount of TDS in a water sample is measured by filtering the sample through a 2.0 µm pore size filter, evaporating the remaining filtrate and then drying what is left to a constant weight at 180ºC. The concentration and composition of TDS in natural waters is determined by the geology of the drainage, atmospheric precipitation and the water balance (evaporation-precipitation. The mean salinity of the world’s rivers is approximately 120 mg Lˉ1 and the major anion found in natural waters is bicarbonate. The most commonly occurring cation in fresh water is calcium. Changes in TDS concentrations in natural waters often result from industrial effluent, changes to the water balance (by limiting inflow, by increased water use or increased precipitation, or by salt-water intrusion. It is recommended that different limits for individual ions, rather than TDS, be used for salmonid species. These limits should be based on the effect of the ion on fertilization and egg development.

  19. [Effects of Different Land Uses on Soil Active Organic Carbon and Nitrogen Fractions in Jinyun Mountain].

    Science.gov (United States)

    Qi, Xin; Jiang, Chang-sheng; Hao, Qing-ju; Li, Jian-lin

    2015-10-01

    In this paper, we take Jinyun Mountain where located in Beibei district of Chongqing as the research object and explore the effect of different ways of land use on soil active organic carbon, nitrogen components by collecting the soil samples from 0 to 60 cm depth in subtropical evergreen broad-leaved forest (hereinafter referred to as the forest), abandoned land, orchard, farmland and measuring the content of MBC, MBN, DOC and DON. The research results show that the contents of soil MBC, MBN, DOC, DON are reduced with the increase of soil depth in four types of land using soils. Variance analysis of the single factor shows that four kinds of land uses have no significant difference in the contents of MBC, MBN and DON, but the DOC content of the abandoned land is significantly higher than that of other three kinds. It shows that the different ways of land use have no obvious effects on soil MBC, MBN and DON but the abandonment of slope cropland can significantly increase the content of soil DOC. There is no significant difference among the distribution ratio of MBN, DOC, DON in forest, abandoned land, orchard and farmland within the soil from 0 to 60 cm, but the distribution ratio of slope MBC is significantly higher than that of other three kinds. It means farmland soil organic carbon has a higher biological activity, this could due to the application of green manure, farmland manure and other organic fertilizers. Under different land utilizations, DOC/DON is the highest, MBC/MBN is the second, and SOC/TN is the lowest. It means the biological solidification of dissolved organic matter is the strongest, and the mineralization of soil organic matter is the most obvious. Under the four kinds of land uses, there are the lowest ratios in SOC/TN, MBC/MBN and DOC/DON in the farmland. And all the ratios are less than 20, which suggest that the mineralization of farmland soil organic matter is stronger and it's easy to cause the loss of soil carbon.

  20. An Industrial Ecology Approach to Municipal Solid Waste Management: II. Case Studies for Recovering Energy from the Organic Fraction of MSW

    Science.gov (United States)

    The organic fraction of municipal solid waste provides abundant opportunities for industrial ecology-based symbiotic use. Energy production, economics, and environmental aspects are analyzed for four alternatives based on different technologies: incineration with energy recovery...

  1. Co-digestion of energy crops and the source-sorted organic fraction of municipal solid waste

    Energy Technology Data Exchange (ETDEWEB)

    Nordberg, A.; Edstrom, M. [Swedish Inst. of Agricultural and Environmental Engineering, Uppsala (Sweden)

    2004-07-01

    Biogas produced from the anaerobic digestion of solid organic wastes is typically used for electricity and heat. However, environmental concerns have generated an interest in upgrading biogas to vehicle fuel quality. This paper presents the results of a laboratory and pilot scale study which examined the biological and technical performance of energy crops (grass and clover) during co-digestion. The source sorted fraction of municipal solid waste (MSW) was also examined. A 50:50 mixture of total solids and source-sorted organic fraction of municipal solids wastes (SS-OFMSW) performed better than a mixture with higher levels of total solids because it had a better nutritional composition. Viscosity was reduced by mincing grassland crops. This measure also reduced fibre floating and scum formation. The rheological properties and electricity requirements were discussed along with the quality of the digester effluent and the economic consequences for production-scale operations. It was noted that the price of raw biogas should be at least 0.078 Euros per kWh in order to balance the costs for full-scale plant operation. 14 refs., 6 tabs., 1 fig.

  2. Uptake of natural organic matter (NOM) fractions by anion exchangers in demineralisation and drinking water plants

    OpenAIRE

    Pürschel, Madlen

    2014-01-01

    The elimination of natural organic matter (NOM) is an important aim of water treatment in demineralisation plants of power stations. NOM is regarded as corrosion risk factor in the steam water cycle because of its potential to decompose into low-molecular-weight (LMW) acids and carbon dioxide. Further, the removal of NOM is also one of the main objectives in the drinking water production, since it can cause i) colour, taste and odour problems, ii) formation of carcinogen halogenated disinfect...

  3. Integer versus Fractional Charge Transfer at Metal(/Insulator)/Organic Interfaces: Cu(/NaCl)/TCNE

    OpenAIRE

    Hofmann, O.; Rinke, P.; Scheffler, M.; Heimel, G.

    2015-01-01

    Semilocal and hybrid density functional theory was used to study the charge transfer and the energy-level alignment at a representative interface between an extended metal substrate and an organic adsorbate layer. Upon suppressing electronic coupling between the adsorbate and the substrate by inserting thin, insulating layers of NaCl, the hybrid functional localizes charge. The laterally inhomogeneous charge distribution resulting from this spontaneous breaking of translational symmetry is re...

  4. Assessing the concentrations of polar organic microcontaminants from point sources in the aquatic environment: measure or model?

    Science.gov (United States)

    Johnson, Andrew C; Ternes, Thomas; Williams, Richard J; Sumpter, John P

    2008-08-01

    To carry out meaningful ecotoxicity studies on novel polar organic microcontaminants, it is essential to know what concentrations wildlife may be exposed to. Traditionally these values were obtained by analytical chemistry, but in recent years GIS water quality models have been developed which may offer a quick and reliable way of getting the same information. Thus, two ways of obtaining basically the same information now exist, and an issue, therefore, arises as to which method is the most appropriate to use in which situation. To address this issue we have critically reviewed and compared measuring and modeling approaches for the determination of sewage effluent and river water concentrations of organic microcontaminants. Where model predictions and chemical measurements can be directly compared in sewage effluents, receiving waters, and across catchments, reported model mean values have all been within 1 order of magnitude of the measured values, with typically no more than a 3- or 4-fold difference. Interlaboratory chemical analysis of some organic microcontaminants in effluents in the challenging ng/L range have provided results which have varied from one another by a similar margin. No such comparison has been carried out yet for GIS water quality models to determine variation in predicted concentrations. As the level of ecotoxicological effects of many chemicals is often considerably higher than the reported measured or modeled values, such errors that might occur will often be of no consequence. But due to their extraordinary potency, much more accuracy is required with some natural and synthetic hormones. Significantly, modeling is no more complex to conduct when dealing with contaminants at ng/L compared with mg/L concentrations, but the same cannot be said for chemical analysis. A combination of modeling and measuring techniques will give the greatest confidence in risk assessment. PMID:18754451

  5. Optical properties of natural dissolved organic matter (DOM) in aquatic ecosystems: Applications in ecosystem studies from headwater streams to the deep ocean. (Invited)

    Science.gov (United States)

    Jaffe, R.

    2010-12-01

    The study of natural dissolved organic material (DOM) contributes to the better understanding of ecosystem function as the carbon flux between environmental compartments represents an important linkage between terrestrial and aquatic ecosystems. Within freshwater and marine ecosystems, DOM typically represents the largest pool of detrital organic carbon and greatly exceeds the organic carbon present in living biomass. Thus, the sources and fate of DOM are important terms in carbon budgets. DOM can also influence ecosystem function by controlling microbial food webs, act as a means of nutrient transport, buffer pH and influence toxicity and bioavailability of pollutants, among others. DOM composition influences its ‘quality’ and thus its photo- and bio-reactivity, both of which exert a strong control of the diagenetic reworking of this carbon pool. However, the molecular composition of DOM is highly complex and diverse, and its characterization is a serious challenge to analytical chemists. In recent years, several novel analytical approaches to the characterization of DOM have evolved, including those that are highly structure specific and others that provide information on broader molecular characteristics. Whilst the former are usually expensive and time consuming, the latter, often based on optical properties measurements, feature high sample throughput at a reduced cost but at the expense of structural specificity. While both approaches are complementary under ideal conditions, the latter are best suited for studies involving large spatial and temporal scales. The analysis of DOM optical properties, in particular excitation emission matrix (EEM) fluorescence combined with parallel factor analysis (PARAFAC), has emerged as a practical tool for the broad characterization of DOM quality. This presentation will provide examples for the application of EEM-PARAFAC in assessing environmental dynamics of DOM on both spatial and temporal scales, and in both

  6. Determination of the biogenic secondary organic aerosol fraction in the boreal forest by AMS and NMR measurements

    Directory of Open Access Journals (Sweden)

    E. Finessi

    2011-08-01

    Full Text Available The study investigates the sources of fine organic aerosol (OA in the boreal forest, based on measurements including both filter sampling (PM1 and online methods and carried out during a one-month campaign held in Hyytiälä, Finland, in spring 2007. Two aerosol mass spectrometers (Q-AMS, ToF-AMS were employed to measure on-line air mass concentrations of major non-refractory aerosol species, while the water extracts of the filter samples were analyzed by nuclear magnetic resonance (NMR spectroscopy for organic functional group characterization of the polar organic fraction of the aerosol. AMS and NMR spectra were processed separately by non-negative factorization algorithms, in order to apportion the main components underlying the submicrometer organic aerosol composition and depict them in terms of both mass fragmentation patterns and functional group compositions.

    The NMR results supported the AMS speciation of oxidized organic aerosol (OOA into two main fractions, which could be generally labelled as more and less oxidized organics. The more oxidized component was characterized by a mass spectrum dominated by the m/z 44 peak, and in parallel by a NMR spectrum showing aromatic and aliphatic backbones highly substituted with oxygenated functional groups (carbonyls/carboxyls and hydroxyls. Such component, contributing on average 50 % of the OA mass throughout the observing period, was associated with pollution outbreaks from the Central Europe. The less oxidized component showed features consistent with less oxygenated aerosols and was enhanced in concomitance with air masses originating from the North-to-West sector, in agreement with previous investigations conducted at this site. NMR factor analysis was able to separate two distinct components under the less oxidized fraction of OA. One of these NMR-factors was associated to the formation of terrestrial biogenic secondary organic aerosol (BSOA, based on the

  7. Characteristics of organic phosphorus fractions in different trophic sediments of lakes from the middle and lower reaches of Yangtze River region and Southwestern Plateau, China

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Runyu [State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002 (China); Graduate School, Chinese Academy of Sciences, Beijing 100039 (China); Wu Fengchang [State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002 (China)], E-mail: wufengchang@vip.skleg.cn; Liu Congqiang; Fu Pingqing; Li Wen; Wang Liying; Liao Haiqing; Guo Jianyang [State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002 (China)

    2008-03-15

    In this study, the characteristics of organic phosphorus (P{sub o}) fractions in sediments of six lakes from the middle and lower reaches of Yangtze River region and Southwestern China Plateau, China were investigated using a soil P{sub o} fractionation scheme, and the relationships between P{sub o}, inorganic phosphorus (P{sub i}) and pollution status were also discussed. The results show that the rank order of P{sub o} fractions was: residual P{sub o} > HCl-P{sub o} > fulvic acid-P > humic acid-P > NaHCO{sub 3}-P{sub o}, with their average relative proportion 8.7:4.6:3.2:2.1:1.0. P{sub o} fractions, especially nonlabile P{sub o}, were significantly correlated with organic matter, P{sub o} and NaOH-P{sub i}. Different distribution patterns of P fractions were observed in those two different regions. P{sub o} fractions in the heavily polluted sediments were higher than those in moderately and no polluted sediments, it is suggested that P{sub o} should be paid more attention in the lake eutrophication investigation. - Organic phosphorus fractions in sediments from 6 different trophic Chinese lakes were characterized using an improved fractionation scheme.

  8. Impacts of low-molecular-weight organic acids on aquatic behavior of graphene nanoplatelets and their induced algal toxicity and antioxidant capacity.

    Science.gov (United States)

    Wang, Zhuang; Gao, Yucheng; Wang, Se; Fang, Hao; Xu, Defu; Zhang, Fan

    2016-06-01

    Knowledge of the interaction between graphene-based materials and low-molecular-weight organic acids (LOAs) is essential to understand fate and effects of graphene-based materials in the aquatic environment, but this interaction remains poorly elucidated. In this study, the effects of LOAs on the physicochemical properties of graphene nanoplatelets (GNPs) in an aqueous medium and on the GNP toxicity to algae were studied. The unicellular green alga Scenedesmus obliquus was exposed to GNP suspensions in the presence of benzoic acid or gallic acid at various concentrations. The GNPs had smaller hydrodynamic sizes and the GNP suspensions were more stable and had higher or lower surface zeta potentials in the presence of LOAs than when LOAs were not present. The toxic effects in S. obliquus cultures incubated with GNP suspensions containing LOAs were related to the LOA concentration, and the presence of LOAs caused three effects: stimulation, alleviation, and synergistic inhibition. The intensities of the effects mainly correlated with the LOA concentration, the extent of agglomeration, and particle-induced oxidative stress. The results indicate that the environmental fates and toxicities of GNPs are strongly affected by the binding of GNPs to LOAs. PMID:26898932

  9. Oxygen demand for the stabilization of the organic fraction of municipal solid waste in passively aerated bioreactors

    Energy Technology Data Exchange (ETDEWEB)

    Kasinski, Slawomir, E-mail: slawomir.kasinski@uwm.edu.pl; Wojnowska-Baryla, Irena

    2014-02-15

    Highlights: • The use of an passively aerated reactor enables effective stabilization of OFMSW. • Convective air flow does not inhibit the aerobic stabilization of waste. • The use of an passively aerated reactor reduces the heat loss due to convection. • The volume of supplied air exceeds 1.7–2.88 times the microorganisms demand. - Abstract: Conventional aerobic waste treatment technologies require the use of aeration devices that actively transport air through the stabilized waste mass, which greatly increases operating costs. In addition, improperly operated active aeration systems, may have the adverse effect of cooling the stabilized biomass. Because active aeration can be a limiting factor for the stabilization process, passive aeration can be equally effective and less expensive. Unfortunately, there are few reports documenting the use of passive aeration systems in municipal waste stabilization. There have been doubts raised as to whether a passive aeration system provides enough oxygen to the organic matter mineralization processes. In this paper, the effectiveness of aeration during aerobic stabilization of four different organic fractions of municipal waste in a reactor with an integrated passive ventilation system and leachate recirculation was analyzed. For the study, four fractions separated by a rotary screen were chosen. Despite the high temperatures in the reactor, the air flow rate was below 0.016 m{sup 3}/h. Using Darcy’s equation, theoretical values of the air flow rate were estimated, depending on the intensity of microbial metabolism and the amount of oxygen required for the oxidation of organic compounds. Calculations showed that the volume of supplied air exceeded the microorganisms demand for oxidation and endogenous activity by 1.7–2.88-fold.

  10. Bioenergy conversion studies of organic fraction of MSW: kinetic studies and gas yield--organic loading relationships for process optimisation.

    Science.gov (United States)

    Rao, M S; Singh, S P

    2004-11-01

    Batch digestion of municipal garbage was carried out for 100 days at room temperature (26+/-4 degrees C; average temperature 25 degrees C) and at ambient temperature (32+/-10 degrees C; average temperature 29 degrees C) conditions for total solids concentrations varying between 45 and 135 g/l. A first order model based on the availability of substrate as the limiting factor was used to perform the kinetic studies of batch anaerobic digestion system. Effect of organic solids concentration and digestion time on biogas yield was studied and mass and energy balance analysis was conducted for batch digestion. The net bioenergy yield from municipal garbage and corresponding bioprocess conversion efficiency over the length of the digestion time were observed to be 12,528 kJ/kg volatile solids and 84.51% respectively. The methane content of the biogas generated from the reactors was in the range of 62-72% with the overall average methane content of the biogas, computed over the total digestion period was 65 vol%. PMID:15246442

  11. Far- and mid-infrared spectroscopy of complex organic matter of astrochemical interest: coal, heavy petroleum fractions and asphaltenes

    Science.gov (United States)

    Cataldo, Franco; García-Hernández, D. A.; Manchado, Arturo

    2013-03-01

    The coexistence of a large variety of molecular species (i.e. aromatic, cycloaliphatic and aliphatic) in several astrophysical environments suggests that unidentified infrared emission (UIE) occurs from small solid particles containing a mix of aromatic and aliphatic structures (e.g. coal, petroleum, etc.), renewing the astronomical interest on this type of materials. A series of heavy petroleum fractions namely `distillate aromatic extract', `Residual Aromatic Extract', heavy aromatic fraction (BQ-1) and asphaltenes derived from BQ-1 were used together with anthracite coal and bitumen as model compounds in matching the band pattern of the emission features of proto-planetary nebulae (PPNe). All the model materials were examined in the mid-infrared (2.5-16.66 μm) and for the first time in the far-infrared (16.66-200 μm), and the infrared bands were compared with the UIE from PPNe. The best match of the PPNe band pattern is offered by the BQ-1 heavy aromatic oil fraction and by its asphaltenes fraction. Particularly interesting is the ability of BQ-1 to match the band pattern of the aromatic-aliphatic C-H stretching bands of certain PPNe, a result which is not achieved neither by the coal model nor by the other petroleum fractions considered here. This study shows that a new interesting molecular model of the emission features of PPNe is asphaltene molecules which are composed by an aromatic core containing three to four condensed aromatic rings surrounded by cycloaliphatic (naphtenic) and aliphatic alkyl chains. Instead, the weakness of the model involving a mixture of polycyclic aromatic hydrocarbons (PAHs) for modelling the aromatic infrared emission bands (AIBs) is shown. The laboratory spectra of these complex organic compounds represent a unique data set of high value for the astronomical community, e.g. they may be compared with the Herschel Space Observatory spectra (˜51-220 μm) of several astrophysical environments such as (proto-) planetary nebulae, H

  12. Fractionation of persistent organic pollutants in fish oil by high-performance liquid chromatography on a 2-(1-pyrenyl)ethyl silica column

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz, X.; Marti, R.; Montana, M.J.; Gasser, M.; Margarit, L.; Broto, F.; Diaz-Ferrero, J. [Institut Quimic de Sarria, Ramon Llull University, Analytical Chemistry Department, Barcelona (Spain)

    2010-09-15

    The analysis of persistent organic pollutants in foodstuffs has become necessary for control of their levels in products for human and animal consumption. These analytical procedures usually require a fractionation step in order to separate the different families of pollutants to avoid interferences during the instrumental determination. In this study the separation was carried out on a 2-(1-pyrenyl)ethyl silica column, where analyte fractionation was based on differences in planarity and aromaticity. The fractionation of several types of persistent organic pollutants found in fish oil samples was studied; the pollutants included polychlorinated dibenzo-p-dioxins and dibenzofurans, polychlorinated biphenyls, polybrominated diphenyl ethers, and some organochlorine pesticides. Fractions were analyzed by high-resolution gas chromatography with electron-capture detection and high-resolution gas chromatography-high resolution mass spectroscopy. Finally, the whole method (including the purification, fractionation, and instrumental determination steps) was validated and successfully applied to the analysis of several samples of fish oil. (orig.)

  13. Effects of free iron oxyhydrates and soil organic matter on copper sorption-desorption behavior by size fractions of aggregates from two paddy soils

    Institute of Scientific and Technical Information of China (English)

    WANG Fang; PAN Genxing; LI Lianqing

    2009-01-01

    Effects of free iron oxyhydrates (Fed) and soil organic matter (SOM) on copper (Cu2+) sorption-desorption behavior by size fractions of aggregates from two typical paddy soils (Ferric-Accumulic Stagnic Anthrosol (Soil H) and Gleyic Stagnic Anthrosol (Soil W)) were investigated with and without treatment of dithionite-citrate-bicarbonate and of H2O2. The size fractions of aggregates were obtained from the undisturbed bulk topsoil using a low energy ultrasonic dispersion procedure. Experiments of equilibrium sorption and subsequent desorption were conducted at soil water ratio of 1:20, 25℃. For Soil H, Cu2+ sorption capacity of the DCB-treated size fractions was decreased by 5.9% for fine sand fraction, by 40.4% for coarse sand fraction, in comparison to 2.9% for the bulk sample. However, Cu2+ sorption capacities of the H2O2-treated fractions were decreased by over 80% for the coarse sand fraction and by 15% for the clay-sized fraction in comparison to 88% for bulk soil. For Soil W, Cu2+ sorption capacity of the DCB-treated size fraction was decreased by 30% for the coarse sand fraction and by over 75% for silt sand fraction in comparison to 44.5% for the bulk sample. Cu2+ sorption capacities of the H2O2-treated fractions were decreased by only 2.0% for the coarse sand fraction and by 15% for the fine sand fraction in comparison to by 3.4% for bulk soil. However, Cu2+ desorption rates were increased much in H2O2-treated samples by over 80% except the clay-sized fraction (only 9.5%) for Soil H. While removal of SOM with H2O2 tendend to increase desorption rate, DCB- and H2O2-treatments caused decrease in Cu2+ retention capacity of size fractions. Particularly, there hardly remained Cu2+ retention capacity by size fractions from Soil H after H2O2 treatment except for clay-sized fraction. These findings supported again the dominance of the coarse sand fraction in sorption of metals and the preference of absorbed metals bound to SOM in differently stabilized status

  14. Carbon and silver nanoparticles in the fight against the filariasis vector Culex quinquefasciatus: genotoxicity and impact on behavioral traits of non-target aquatic organisms.

    Science.gov (United States)

    Murugan, Kadarkarai; Nataraj, Devaraj; Madhiyazhagan, Pari; Sujitha, Vasu; Chandramohan, Balamurugan; Panneerselvam, Chellasamy; Dinesh, Devakumar; Chandirasekar, Ramachandran; Kovendan, Kalimuthu; Suresh, Udaiyan; Subramaniam, Jayapal; Paulpandi, Manickam; Vadivalagan, Chithravel; Rajaganesh, Rajapandian; Wei, Hui; Syuhei, Ban; Aziz, Al Thabiani; Alsalhi, Mohamad Saleh; Devanesan, Sandhanasamy; Nicoletti, Marcello; Canale, Angelo; Benelli, Giovanni

    2016-03-01

    Mosquito-borne diseases represent a deadly threat for millions of people worldwide. The Culex genus, with special reference to Culex quinquefasciatus, comprises the most common vectors of filariasis across urban and semi-urban areas of Asia. In recent years, important efforts have been conducted to propose green-synthesized nanoparticles as a valuable alternative to synthetic insecticides. However, the mosquitocidal potential of carbon nanoparticles has been scarcely investigated. In this study, the larvicidal and pupicidal activity of carbon nanoparticle (CNP) and silver nanoparticle (AgNP) was tested against Cx. quinquefasciatus. UV-Vis spectrophotometry, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray (EDX) spectroscopy, and Raman analysis confirmed the rapid and cheap synthesis of carbon and silver nanoparticles. In laboratory assays, LC50 (lethal concentration that kills 50 % of the exposed organisms) values ranged from 8.752 ppm (first-instar larvae) to 18.676 ppm (pupae) for silver nanoparticles and from 6.373 ppm (first-instar larvae) to 14.849 ppm (pupae) for carbon nanoparticles. The predation efficiency of the water bug Lethocerus indicus after a single treatment with low doses of silver and carbon nanoparticles was not reduced. Moderate evidence of genotoxic effects induced by exposure to carbon nanoparticles was found on non-target goldfish, Carassius auratus. Lastly, the plant extract used for silver nanosynthesis was tested for 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging activity. Overall, our results pointed out that AgNP and CNP can be a candidate for effective tools to reduce larval and pupal populations of filariasis vectors, with reduced genotoxicity and impact on behavioral traits of other aquatic organisms sharing the same ecological

  15. Facile biosynthesis of silver nanoparticles using Barleria cristata: mosquitocidal potential and biotoxicity on three non-target aquatic organisms.

    Science.gov (United States)

    Govindarajan, Marimuthu; Benelli, Giovanni

    2016-03-01

    Mosquitoes (Diptera: Culicidae) act as vectors of important pathogens and parasites, such as malaria, dengue, chikungunya, Japanese encephalitis and lymphatic filariasis. The use of synthetic mosquitocides often leads to high operational costs and adverse non-target effects. Recently, plant-borne compounds have been proposed for rapid extracellular biosynthesis of mosquitocidal nanoparticles. However, the impact of these nanomosquitocides against biological control agents of mosquito larval populations has been poorly studied. In this research, we biosynthesized silver nanoparticles (Ag NP) using the Barleria cristata leaf extract as a reducing and stabilizing agent. The biosynthesis of Ag NP was confirmed analyzing the excitation of surface plasmon resonance using ultraviolet-visible (UV-vis) spectrophotometry. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) showed the clustered and irregular shapes of Ag NP. The presence of silver was confirmed by energy-dispersive X-ray (EDX) spectroscopy. Fourier transform infrared (FTIR) spectroscopy investigated the identity of secondary metabolites, which may also act as Ag NP capping agents. The acute toxicity of B. cristata leaf extract and biosynthesized Ag NP was evaluated against larvae of Anopheles subpictus, Aedes albopictus, and Culex tritaeniorhynchus. Compared to the leaf aqueous extract, biosynthesized Ag NP showed higher toxicity against An. subpictus, Ae. albopictus, and Cx. tritaeniorhynchus with lethal concentration (LC)50 values of 12.46, 13.49, and 15.01 μg/mL, respectively. Notably, biosynthesized Ag NP were found safer to non-target organisms Diplonychus indicus, Anisops bouvieri, and Gambusia affinis, with respective LC50 values ranging from 633.26 to 866.92 μg/mL. Overall, our results highlight that B. cristata-fabricated Ag NP are a promising and eco-friendly tool against young instar populations of mosquito vectors of medical and veterinary importance.

  16. Ozonolysis of beta-pinene: temperature dependence of secondary organic aerosol mass fraction.

    Science.gov (United States)

    Pathak, Ravikant; Donahue, Neil M; Pandis, Spyros N

    2008-07-15

    The SOA formation from beta-pinene ozonolysis at modest precursor concentrations (2-40 ppb) was investigated in the temperature range of 0-40 degrees C. The presence of inert seeds and high ozone concentrations is necessary to minimize losses of semivolatile vapors to the walls of the smog chamber. beta-pinene secondary organic aerosol production increases significantly with decreasing temperature. An increase by a factor of 2-3, depending on the reacted beta-pinene concentration, was observed as the temperature decreased from 40 to 0 degrees C. This increase appearsto be due mainly to the shifting of partitioning of the semivolatile SOA componentstoward the particulate phase and not to a change of the beta-pinene product distribution with temperature. The measurements are used to develop a new temperature-dependent parametrization for the four-component basis-set. The parametrization predicts much higher SOA production for beta-pinene ozonolysis for typical atmospheric conditions than the values that have been suggested by previous studies.

  17. Quantitative Phase Fraction Detection in Organic Photovoltaic Materials through EELS Imaging

    Directory of Open Access Journals (Sweden)

    Ondrej Dyck

    2015-11-01

    Full Text Available Organic photovoltaic materials have recently seen intense interest from the research community. Improvements in device performance are occurring at an impressive rate; however, visualization of the active layer phase separation still remains a challenge. This paper outlines the application of two electron energy-loss spectroscopic (EELS imaging techniques that can complement and enhance current phase detection techniques. Specifically, the bulk plasmon peak position, often used to produce contrast between phases in energy filtered transmission electron microscopy (EFTEM, is quantitatively mapped across a sample cross section. A complementary spectrum image capturing the carbon and sulfur core loss edges is compared with the plasmon peak map and found to agree quite well, indicating that carbon and sulfur density differences between the two phases also allows phase discrimination. Additionally, an analytical technique for determining absolute atomic areal density is used to produce an absolute carbon and sulfur areal density map. We show how these maps may be re-interpreted as a phase ratio map, giving quantitative information about the purity of the phases within the junction.

  18. Organic matter fractions and soil fertility under the influence of liming, vermicompost and cattle manure

    Directory of Open Access Journals (Sweden)

    Yagi Renato

    2003-01-01

    Full Text Available This work evaluates effects of cattle manure vermicompost in association with liming on soil fertility indexes. The experiment was carried out in greenhouse conditions, in pots containing samples of a Typic Hapludox, medium-textured soil. Five levels of vermicompost (equivalent to 0, 28, 42, 56, and 70 t ha-1, dry weight and five liming levels (to raise base saturation to 20, 30, 40, 50, and 60% were combined in a factorial scheme and samples were incubated for 180 days. Samples of the same soil received the equivalent to 70 t ha-1 of the cattle manure used to produce the vermicompost, and the same lime rates. Cattle manure was better than vermicompost to supply K and Mg. Small differences in P supply were observed between the manures. The vermicompost increased the levels of Ca, pH, organic matter (OM and CEC more than the manure. C-humic acids decreased and C-humin increased with vermicompost application. With liming, C-humic acids decreased, but the total content of OM was not affected.

  19. Sorption of Triton X-100 on soil organic matter fractions:Kinetics and isotherms

    Institute of Scientific and Technical Information of China (English)

    ZHANG Guangzhi; HU Hao; SUN Weiling; NI Jinren

    2009-01-01

    Kinetics and isotherms of Triton X-100 sorption on soil,base-extracted soil(BE),humic acid (HA) and humin (HM) were investigated respectively to get better understanding on characteristics of the surfactant sorptiun onto different soil organic matters(SOMs).It was demonstrated that the kinetics results could be satisfactorily described by the pseudo-second order model.The half of the time to reach equilibrium(t1/2) for different sorbents followed the sequence of soil>HA>BE>HM.Furthermore,the calculated equilibrium sorption capacity(Ceq) was found in the sequence of HA>BE>HM>soil,which agreed well with the experimental results.The isotherms of Triton X-100 sorption on soil and HA could be well described by the S-type isotherm,but BE and HM by the L-type.The isotherms of all the four sorbents were found reasonably fitted to the Langmuir equation.The Kd value,defined as the ratio of Triton X-100 in sorbent and in the equilibrium solution for given concentrations,generally followed the order of HM>HA>soil>BE.Separated HM and HA showed high affinity for Triton X-100,but the HA and HM in soil and BE were tightly bounded by the minerals.Thus,the HA on the soil surface might dominate the sorption,whereas the bounded HM would play a key role upon the surfactants being penetrated inside the soil.

  20. Comparative toxicity test of water-accommodated fractions of oils and oil dispersants to marine organisms

    International Nuclear Information System (INIS)

    This reference method describes a simple procedure for comparing the toxicity of oil, oil dispersants, and mixtures thereof, to marine animals. It allows the toxicity of different dispersants to be rapidly compared to that of oil, or of a mixture of oil an oil dispersant. It is designed for routine monitoring and screening purposes and is not appropriate as a research method. The physical and chemical properties of oil dispersants create many difficulties in the measurements of their toxicity to marine organisms. Strictly speaking, their toxicity can only be accurately estimated using complex procedures and apparatus. (A relatively simple apparatus for preparing oil/water or oil/water/oil dispersant emulsions is described in Appendix B). Simpler methods can provide useful information, provided their limitations are clearly understood and taken into consideration in the assessment and application of their results. Some of the special considerations relating to the measurement of the toxicity of oil and oil dispersants are described in Appendix A. The Appendix also explains the rationale and limitations of the method described here. 3 refs, 4 figs, 2 tabs

  1. Aberrant Global and Regional Topological Organization of the Fractional Anisotropy-weighted Brain Structural Networks in Major Depressive Disorder

    Institute of Scientific and Technical Information of China (English)

    Jian-Huai Chen; Zhi-Jian Yao; Jiao-Long Qin; Rui Yan; Ling-Ling Hua; Qing Lu

    2016-01-01

    Background:Most previous neuroimaging studies have focused on the structural and functional abnormalities of local brain regions in major depressive disorder (MDD).Moreover,the exactly topological organization of networks underlying MDD remains unclear.This study examined the aberrant global and regional topological patterns of the brain white matter networks in MDD patients.Methods:The diffusion tensor imaging data were obtained from 27 patients with MDD and 40 healthy controls.The brain fractional anisotropy-weighted structural networks were constructed,and the global network and regional nodal metrics of the networks were explored by the complex network theory.Results:Compared with the healthy controls,the brain structural network of MDD patients showed an intact small-world topology,but significantly abnormal global network topological organization and regional nodal characteristic of the network in MDD were found.Our findings also indicated that the brain structural networks in MDD patients become a less strongly integrated network with a reduced central role of some key brain regions.Conclusions:All these resulted in a less optimal topological organization of networks underlying MDD patients,including an impaired capability of local information processing,reduced centrality of some brain regions and limited capacity to integrate information across different regions.Thus,these global network and regional node-level aberrations might contribute to understanding the pathogenesis of MDD from the view of the brain network.

  2. A new approach to the kinetic study of anaerobic degradation of the organic fraction of municipal solid waste

    Energy Technology Data Exchange (ETDEWEB)

    Cecchi, Franco; Traverso, P.G.; Fazzini, Guido (Venice Univ. (IT). Dip. Scienze Ambientali); Alvarez, J.M. (Barcelona Univ. (ES). Dip. d' Enginyeria Quimica i Metallurgia); Medici, Franco (L' Aquila Univ. (IT). Dip. di Chimica Ingegneria Chimica e Materiali)

    1990-01-01

    The kinetic models proposed by Monod, Chen and Hashimoto and Singh as well as those of a first order and diffusional type have been tested for fit as mathematical descriptions to describe substrate utilization during anaerobic digestion of the organic fraction of source sorted municipal solid waste. A new model, described as step diffusional is proposed and the results obtained with it are compared with those obtained using previously published models. The new model is found to show a better fit to the experimental result than those obtained with other models. The new model takes into account simple qualitative and quantitative chemical characteristics of the substrate to be digested. Although this new model is more complex than some others since it involves four kinetic constants, conceptually it is simple enough to find practical applications. (author).

  3. Operational strategies for thermophilic anaerobic digestion of organic fraction of municipal solid waste in continuously stirred tank reactors

    DEFF Research Database (Denmark)

    Angelidaki, Irini; Cui, J.; Chen, X.;

    2006-01-01

    Three operational strategies to reduce inhibition due to ammonia during thermophilic anaerobic digestion of source-sorted organic fraction of municipal solid waste (SS-OFMSW) rich in proteins were investigated. Feed was prepared by diluting SS-OFMSW (ratio of 1:4) with tap water or reactor process...... water with or without stripping ammonia. Three continuously stirred tank reactors were operated at 55 degrees C with 11.4 gVS d(-1) loading rate and 15 d retention time. Total ammonia nitrogen (TAN) level in the reactor fed with recirculated water alone was spiked to 3.5 and 5.5 g-N l(-1) through...... ammonium bicarbonate additions. Dilution of SS-OFMSW with fresh water showed a stable performance with volatile fatty acids of water after stripping ammonia showed even better performance with a methane yield...

  4. Enhancing the hydrolysis process of a two-stage biogas technology for the organic fraction of municipal solid waste

    DEFF Research Database (Denmark)

    Nasir, Zeeshan; Uellendahl, Hinrich

    2015-01-01

    The Danish company Solum A/S has developed a two-stage dry anaerobic digestion process labelled AIKAN® for the biological conversion of the organic fraction of municipal solid waste (OFMSW) into biogas and compost. In the AIKAN® process design the methanogenic (2nd) stage is separated from...... time, recirculation rate of percolate, ratio of admixing effluent from the anaerobic stage to the percolate, water submerge of waste) on the efficiency of the hydrolytic stage. •The effect of addition of adapted mixed cultures and specific hydrolytic microorganisms on the hydrolysis of the waste. •The...... effect of addition of hydrolytic enzymes on the hydrolysis of the waste. The efficiency of the hydrolysis is determined for the different conditions applied both by the release of volatile fatty acids from the hydrolytic stage and by final biomethane potential (BMP) tests. The tests are performed both...

  5. Organic Matter Fractions and Quality of the Surface Layer of a Constructed and Vegetated Soil After Coal Mining. II - Physical Compartments and Carbon Management Index

    Directory of Open Access Journals (Sweden)

    Otávio dos Anjos Leal

    2015-06-01

    Full Text Available Soils constructed after mining often have low carbon (C stocks and low quality of organic matter (OM. Cover crops are decisive for the recovery process of these stocks, improving the quality of constructed soils. Therefore, the goal of this study was to evaluate the effect of cover crops on total organic C (TOC stocks, C distribution in physical fractions of OM and the C management index (CMI of a soil constructed after coal mining. The experiment was initiated in 2003 with six treatments: Hemarthria altissima (T1, Paspalum notatum (T2, Cynodon dactylon (T3, Urochloa brizantha (T4, bare constructed soil (T5, and natural soil (T6. Soil samples were collected in 2009 from the 0.00-0.03 m layer, and the TOC and C stocks in the physical particle size fractions (carbon in the coarse fraction - CCF, and mineral-associated carbon - MAC and density fractions (free light fraction - FLF; occluded light fraction - OLF, and heavy fraction - HF of OM were determined. The CMI components: carbon pool index (CPI, lability (L and lability index (LI were estimated by both fractionation methods. No differences were observed between TOC, CCF and MAC stocks. The lowest C stocks in FLF and OLF fractions were presented by T2, 0.86 and 0.61 Mg ha-1, respectively. The values of TOC stock, C stock in physical fractions and CMI were intermediate, greater than T5 and lower than T6 in all treatments, indicating the partial recovery of soil quality. As a result of the better adaptation of the species Hemarthria and Brizantha, resulting in greater accumulation of labile organic material, the CPI, L, LI and CMI values were higher in these treatments, suggesting a greater potential of these species for recovery of constructed soils.

  6. Biological nutrients removal from the supernatant originating from the anaerobic digestion of the organic fraction of municipal solid waste.

    Science.gov (United States)

    Malamis, S; Katsou, E; Di Fabio, S; Bolzonella, D; Fatone, F

    2014-09-01

    This study critically evaluates the biological processes and techniques applied to remove nitrogen and phosphorus from the anaerobic supernatant produced from the treatment of the organic fraction of municipal solid waste (OFMSW) and from its co-digestion with other biodegradable organic waste (BOW) streams. The wide application of anaerobic digestion for the treatment of several organic waste streams results in the production of high quantities of anaerobic effluents. Such effluents are characterized by high nutrient content, because organic and particulate nitrogen and phosphorus are hydrolyzed in the anaerobic digestion process. Consequently, adequate post-treatment is required in order to comply with the existing land application and discharge legislation in the European Union countries. This may include physicochemical and biological processes, with the latter being more advantageous due to their lower cost. Nitrogen removal is accomplished through the conventional nitrification/denitrification, nitritation/denitritation and the complete autotrophic nitrogen removal process; the latter is accomplished by nitritation coupled with the anoxic ammonium oxidation process. As anaerobic digestion effluents are characterized by low COD/TKN ratio, conventional denitrification/nitrification is not an attractive option; short-cut nitrogen removal processes are more promising. Both suspended and attached growth processes have been employed to treat the anaerobic supernatant. Specifically, the sequencing batch reactor, the membrane bioreactor, the conventional activated sludge and the moving bed biofilm reactor processes have been investigated. Physicochemical phosphorus removal via struvite precipitation has been extensively examined. Enhanced biological phosphorus removal from the anaerobic supernatant can take place through the sequencing anaerobic/aerobic process. More recently, denitrifying phosphorus removal via nitrite or nitrate has been explored. The removal of

  7. Characteristics of C-, N-DBPs formation from algal organic matter: role of molecular weight fractions and impacts of pre-ozonation.

    Science.gov (United States)

    Zhou, Shiqing; Zhu, Shumin; Shao, Yisheng; Gao, Naiyun

    2015-04-01

    Extracellular organic matter (EOM) and intracellular organic matter (IOM) of Microcystis aeruginosa have been reported to contribute to the formation of carbonaceous disinfection by-products (C-DBPs) and nitrogenous disinfection by-products (N-DBPs). Little is known about DBPs formation from different molecular weight (MW) fractions, especially for N-nitrosodimethylamine (NDMA). This study fractionated EOM and IOM into several MW fractions using a series of ultrafiltration membranes and is the first to report on the C-DBPs and N-DBPs formation from chlorination and chloramination of different MW fractions. Results showed that EOM and IOM were mainly distributed in low-MW (100 KDa) fractions. Additionally, the low-MW and high-MW fractions of EOM and IOM generally took an important part in forming C-DBPs and N-DBPs, either in chlorination or in chloramination. Furthermore, the effects of pre-ozonation on the formation of DBPs in subsequent chlorination and chloramination were also investigated. It was found that ozone shifted the high-MW fractions of EOM and IOM into lower MW fractions and increased the C-DBPs and N-DBPs yields to different degrees. As low-MW fractions are more difficult to remove than high-MW fractions by conventional treatment processes, therefore, activated carbon adsorption, nanofiltration (NF) and biological treatment processes can be ideal to remove the low-MW fractions and minimize the formation potential of C-DBPs and N-DBPs. Moreover, the use of ozone should be carefully considered in the treatment of algal-rich water.

  8. 长三角地区毒死蜱水生生物基准研究%The Aquatic Organism Criteria for Chlorpyrifos in the Yangtze River Delta Region

    Institute of Scientific and Technical Information of China (English)

    王香兰; 周军英; 王蕾; 单正军; 葛峰; 张国祥

    2013-01-01

    [Methods] The toxicity data of 14 representative aquatic organisms was obtained through the toxicity tests. The aquatic organism criteria for chlorpyrifos in the Yangtze River Delta Region was derived by assessment factor, species sensitivity distributions and toxicity percentile rank respectively. [Results] The aquatic organism criteria of 0.013,0.112 and 0.021 μg/L was derived by assessment factor, species sensitivity distributions, and toxicity percentile rank. The differences of the criteria were compared. The reasons were analysed that the aquatic organism criteria for chlorpyrifos in the Yangtze River Delta Region was different from America, Canada, Australia and New Zealand. [Conclusions] The obtained results could provide scientific basis for the water quality criteria formulating.%[方法]通过毒性试验,得出毒死蜱对长三角地区14种代表性水生生物的毒性数据.分别采用评价因子法、物种敏感度分布法和毒性百分数排序法,推导长三角地区毒死蜱水生生物基准值.[结果]评价因子法、物种敏感度分布法和毒性百分数排序法得出的基准值分别是0.013、0.112、0.021 μg/L.比较了3种方法得出的基准值之间的差异,分析了长三角地区毒死蜱水生生物基准与美国、加拿大、澳大利亚和新西兰的基准值不同的原因.[结论]可为我国农药水质标准制订提供科学依据.

  9. Acute toxicity of smoke screen materials to aquatic organisms, white phosphorus-felt, red phosphorus-butyl rubber and SGF No. 2 fog oil. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Poston, T.M.; McFadden, K.M.; Bean, R.M.; Clark, M.L.; Thomas, B.L.; Killand, B.W.; Prohammer, L.A.; Kalkwarf, D.R.

    1986-04-01

    The acute toxicity of three obscurants was determined for nine freshwater organisms. The materials tested were white phosphorus-felt smoke, red phosphorus-butyl rubber (RP-BR) smoke, and smoke generator fuel (SGF) No. 2 fog oil (bulk and vaporized). The chemistry of WP-F and RP-BR smoke in water and the resulting effects on aquatic organisms are similar. Combustion of these two obscurants and their deposition in water leads to the formation of many complex oxy-phosphoric acids. Rates of hydrolysis of these complex products to ortho-phosphate were inconsistent and unpredictable over time. These products acidify water and produce toxic effects after exhausting the buffering capacity of the water. Acute 96 hr tests using Daphnia magna with neutralized and nonneutralized exposure solutions indicated that the presence of unidentified toxic component(s) acted independently of pH. At pH levels of 6.0 to 7.0, phosphorus combustion products precipitated out of solution leading to a bimodal toxic response in extended 96-hr tests with Daphnia magna. Most components of fog oil had low solubility in water. Saturation was apparent at approximately 0.1 to 0.3 mg/L total oil. Vaporization had no demonstrable effect on the chemistry or toxicity of the fog oil. Neither the bulk fog oil nor the vaporized fog oil was acutely toxic to freshwater animals at concentrations less than 10 mg/L total oil. In oil-water mixes in excess of 1.0 mg/L total oil, fog oil quickly separated and floated to the surface. The primary hazard associated with vaporized and bulk fog oil was the physical effect of oil fouling the organisms. Photolysis increased the concentration of water-soluble components of the fog oil. Acute toxicity was demonstrated in oil-water mixes (approx.10 mg/L total oil) of photolyzed bulk and vaporized fog oil. No difference in toxicity was observed between photolyzed and non-photolyzed dilutions of OWM at comparable levels of total oil.

  10. Aquatic pathways model to predict the fate of phenolic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Aaberg, R.L.; Peloquin, R.A.; Strenge, D.L.; Mellinger, P.J.

    1983-04-01

    Organic materials released from energy-related activities could affect human health and the environment. To better assess possible impacts, we developed a model to predict the fate of spills or discharges of pollutants into flowing or static bodies of fresh water. A computer code, Aquatic Pathways Model (APM), was written to implement the model. The computer programs use compartmental analysis to simulate aquatic ecosystems. The APM estimates the concentrations of chemicals in fish tissue, water and sediment, and is therefore useful for assessing exposure to humans through aquatic pathways. The APM will consider any aquatic pathway for which the user has transport data. Additionally, APM will estimate transport rates from physical and chemical properties of chemicals between several key compartments. The major pathways considered are biodegradation, fish and sediment uptake, photolysis, and evaporation. The model has been implemented with parameters for distribution of phenols, an important class of compounds found in the water-soluble fractions of coal liquids. Current modeling efforts show that, in comparison with many pesticides and polyaromatic hydrocarbons (PAH), the lighter phenolics (the cresols) are not persistent in the environment. The properties of heavier molecular weight phenolics (indanols, naphthols) are not well enough understood at this time to make similar judgements. For the twelve phenolics studied, biodegradation appears to be the major pathway for elimination from aquatic environments. A pond system simulation (using APM) of a spill of solvent refined coal (SRC-II) materials indicates that phenol, cresols, and other single cyclic phenolics are degraded to 16 to 25 percent of their original concentrations within 30 hours. Adsorption of these compounds into sediments and accumulation by fish was minor.

  11. Analysis of biomagnification of persistent organic pollutants in the aquatic food web of the Mekong Delta, South Vietnam using stable carbon and nitrogen isotopes.

    Science.gov (United States)

    Ikemoto, Tokutaka; Tu, Nguyen Phuc Cam; Watanabe, Michio X; Okuda, Noboru; Omori, Koji; Tanabe, Shinsuke; Tuyen, Bui Cach; Takeuchi, Ichiro

    2008-05-01

    The present study elucidated the biomagnification profiles of persistent organic pollutants (POPs) through a tropical aquatic food web of Vietnam based on trophic characterization using stable nitrogen analysis. Various biological samples collected from the main stream of the Mekong Delta were provided for the analysis for both POPs, and stable nitrogen and carbon isotope ratios. Of the POPs analyzed, dichlorodiphenyltrichloroethane and its metabolites (DDTs) were the predominant contaminants with concentrations ranging from 0.058 to 12 ng/g wet weight, followed by polychlorinated biphenyls (PCBs) at 0.017-8.9 ng/g, chlordane compounds (CHLs) at 0.0043-0.76 ng/g, tris-4-chlorophenyl methane (TCPMe) at N.D.-0.26 ng/g, hexachlorocyclohexane isomers (HCHs) at N.D.-0.20 ng/g and hexachlorobenzene (HCB) at 0.0021-0.096 ng/g. Significant positive increases of concentrations in DDTs, CHLs, and TCPMe against the stable nitrogen ratio (delta(15)N) were detected, while, concentrations of HCHs and HCB showed no significant increase. The slopes of the regression equations between the log-transformed concentrations of these POPs and delta(15)N were used as indices of biomagnification. The slopes of the POPs for which positive biomagnification was detected ranged from 0.149 to 0.177 on a wet weight basis. The slopes of DDTs and CHLs were less than those reported for a marine food web of the Arctic Ocean, indicating that less biomagnification had occurred in the tropical food web. Of the isomers of CHLs, unlike the studies of the Arctic Ocean, oxychlordane did not undergo significant biomagnification through the food web of the Mekong Delta. This difference is considered to be due to a lack of marine mammals, which might metabolize cis- and trans-chlordane to oxychlordane, in the Mekong Delta ecosystem. The biomagnification profile of TCPMe is reported for the first time in the present study. PMID:18313720

  12. 应用Abraham方程研究有机污染物对七种水生生物的毒性∗%Study on the toxicity of organic pollutants to seven aquatic organisms based on Abraham model

    Institute of Scientific and Technical Information of China (English)

    于洋; 王晓红; 闻洋; 赵元慧

    2015-01-01

    The toxicities of 141 organic pollutants to seven aquatic organisms ( Vibrio fischeri, River bacteria, Scenedesmus obliguue, Daphnia magna, Cyprinuscarpio, Pimephalespromelas, Poeciliareticulata) were analyzed. A linear relationship between the toxicity data of non⁃polar or polar narcotics and hydrophobicity (lgKow) was established for the seven species, respectively. This relationship was interpretated based on the theoretical consideration. Meanwhile, quantitative structure⁃activity relationship ( QSAR) studies were performed between the toxicities of seven aquatic organisms and Abraham descriptors. The mechanisms of action to seven species were analyzed theoretically based on Abraham descriptors and model coefficients. The principal component analysis carried out on the regression coefficients of Abraham models shows that there are interspecies similarities and differences between the species. In the same time, the interspecies correlation of organic pollutants to seven aquatic organisms was analyzed. The results show that there are good interspecies corrections between fish species, marine bacterium and fish or daphnia magna and fish. It is suggested that some compounds shared the same toxic mechanism of action between the species. However , poor interspecies relationships found between toxicities to algae and daphnia magna or fish suggested that compounds have different toxic mechanism of action between these species.%通过研究141种对7种水生生物(发光菌、江水细菌、绿藻、大型溞、鲤鱼、黑头呆鱼,古比鱼)的毒性,建立了非极性麻醉型和极性麻醉型有机物的毒性与辛醇/水分配系数的对数lgKow的相关性,并对该相关性进行了理论解释。同时,建立了Abraham参数与7种水生生物毒性的预测模型,根据Abraham参数和预测模型的系数,对有机污染物与生物毒性作用机理进行了理论分析。在此基础上,对Abraham毒性模型回归系数进行主

  13. Estimation of energy potential from organic fractions of municipal solid waste by using empirical models at hyderabad, Pakistan

    International Nuclear Information System (INIS)

    MSW (Municipal Solid Waste) now-a-day is considered as a precious renewable energy resource for various purposes. In view of above fact, one hundred samples of MSW were collected from different locations of study area. Quantities of each organic waste component were determined by using physical balance and also their proximate analysis was performed by using oven and muffle furnace. In this study, nine empirical models were used for estimating the energy value in terms of heat from OFMSW (Organic Fractions of Municipal Solid Waste), namely two of them were based upon physical composition, four of them were on the basis of its proximate analysis and remaining three of them was according to ultimate analysis of OFMSW. From comparison of all energy models, the empirical Model No. 3 and No. 4 based upon proximate analysis have highest energy recovery potential than all of others. Moreover, the result of Model No.3 on the basis of proximate analysis is closer to the calorific value of mixed OFMSW than the values obtained by rest of models. Therefore, this is the best model to be used. From the outcomes of this study it can be realized that the energy recovery from the OFMSW plays a vital role for economical growth of the country. On that account, a systematic approach should be performed in detail before making a decision on such option. (author)

  14. Performance and kinetic study of semi-dry thermophilic anaerobic digestion of organic fraction of municipal solid waste

    Energy Technology Data Exchange (ETDEWEB)

    Sajeena Beevi, B., E-mail: sajeenanazer@gmail.com [Department of Chemical Engineering, Govt. Engineering College, Thrissur, Kerala 680 009 (India); Madhu, G., E-mail: profmadhugopal@gmail.com [Division of Safety & Fire Engineering, School of Engineering, Cochin University of Science and Technology, Cochin, Kerala 682 022 (India); Sahoo, Deepak Kumar, E-mail: dksahoo@gmail.com [Division of Safety & Fire Engineering, School of Engineering, Cochin University of Science and Technology, Cochin, Kerala 682 022 (India)

    2015-02-15

    Highlights: • Performance of the reactor was evaluated by the degradation of volatile solids. • Biogas yield at the end of the digestion was 52.9 L/kg VS. • Value of reaction rate constant, k, obtained was 0.0249 day{sup −1}. • During the digestion 66.7% of the volatile solid degradation was obtained. - Abstract: Anaerobic digestion (AD) of the organic fraction of municipal solid waste (OFMSW) is promoted as an energy source and waste disposal. In this study semi dry anaerobic digestion of organic solid wastes was conducted for 45 days in a lab-scale batch experiment for total solid concentration of 100 g/L for investigating the start-up performances under thermophilic condition (50 °C). The performance of the reactor was evaluated by measuring the daily biogas production and calculating the degradation of total solids and the total volatile solids. The biogas yield at the end of the digestion was 52.9 L/kg VS (volatile solid) for the total solid (TS) concentration of 100 g/L. About 66.7% of the volatile solid degradation was obtained during the digestion. A first order model based on the availability of substrate as the limiting factor was used to perform the kinetic studies of batch anaerobic digestion system. The value of reaction rate constant, k, obtained was 0.0249 day{sup −1}.

  15. Comparison of two anaerobic systems for hydrogen production from the organic fraction of municipal solid waste and synthetic wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Alzate-Gaviria, Liliana M. [Centro de Investigacion en Energia-UNAM, 62580 Temixco, Morelos (Mexico); Sebastian, P.J. [Centro de Investigacion en Energia-UNAM, 62580 Temixco, Morelos (Mexico); Universidad Politecnica de Chiapas, 29010 Tuxtla Gutierrez, Chiapas (Mexico); Perez-Hernandez, Antonino [Centro de Investigacion en Materiales Avanzados, Miguel de Cervantes 120, Complejo Industrial Chihuahua, Chihuahua 31109 (Mexico); Eapen, D. [Universidad Politecnica de Chiapas, 29010 Tuxtla Gutierrez, Chiapas (Mexico)

    2007-10-15

    Two laboratory scale anaerobic digestion systems for hydrogen production from organic fraction of municipal solid waste (OFMSW) and synthetic wastewater were compared in this study. One of them was formed by a coupled packed bed reactor (PBR) containing 19.4 L of OFMSW and the other an upflow anaerobic sludge bed (UASB) of 3.85 L. The reactors were inoculated with a mixture of non-anaerobic inocula. In the UASB the percentage of hydrogen yield reached 51% v/v and 127NmLH{sub 2}/gvs removed with a hydraulic retention time (HRT) of 24 h. The concentration of synthetic wastewater in the affluent was 7 g COD/L. For the PBR the percentage yield was 47% v/v and 99NmLH{sub 2}/gvs removed with a mass retention time (MRT) of 50 days and the organic load rate of 16 gvs (Grams Volatile Solids)/(kg-day). The UASB and PBR systems presented maximum hydrogen yields of 30% and 23%, respectively, which correspond to 4molH{sub 2}/mol glucose. These values are similar to those reported in the literature for the hydrogen yield (37%) in mesophilic range. The acetic and butyric acids were present in the effluent as by-products in watery phase. In this work we used non-anaerobic inocula made up of microorganism consortium unlike other works where pure inocula or that from anaerobic sludge was used. (author)

  16. Co-digestion of energy crops and the source-sorted organic fraction of municipal solid waste.

    Science.gov (United States)

    Nordberg, A; Edström, M

    2005-01-01

    The biological and technical performance during co-digestion of energy crops and the source-sorted organic fraction of municipal solid waste has been investigated at laboratory and pilot scale. A 50:50 (TS-based) mixture of energy crops and organic waste reached a loading rate of 6.0 gVS L(-1)d(-1) with a methane yield of 0.33-0.38 LgVS(-1), while a 80:20 mixture showed elevated levels of volatile fatty acids at 5.5 gVS L(-1)d(-1) The better performance of the 50:50 mixture can partly be explained by a better nutritional composition. Mincing the ley crop reduced viscosity and reduced problems with fibre floating and scum-blanket formation. The electricity consumed for mincing and stirring at a full-scale plant corresponds to ca 3% of the energy produced. Calculations of the costs for full-scale plants indicate that the price of the upgraded biogas has to be at least 0.078 Euro/kWh in order to balance the costs. PMID:16180431

  17. Estimation of Energy Potential from Organic Fractions of Municipal Solid Waste by Using Empirical Models at Hyderabad, Pakistan.

    Directory of Open Access Journals (Sweden)

    Muhammad Safar Korai

    2016-01-01

    Full Text Available MSW (Municipal Solid Waste now-a-day is considered as a precious renewable energy resource for various purposes. In view of above fact, one hundred samples of MSW were collected from different locations of study area. Quantities of each organic waste component were determined by using physical balance and also their proximate analysis was performed by using oven and muffle furnace. In this study, nine empirical models were used for estimating the energy value in terms of heat from OFMSW (Organic Fractions of Municipal Solid Waste, namely two of them were based upon physical composition, four of them were on the basis of its proximate analysis and remaining three of them was according to ultimate analysis of OFMSW. From comparison of all energy models, the empirical Model No. 3 and No. 4 based upon proximate analysis have highest energy recovery potential than all of others. Moreover, the result of Model No.3 on the basis of proximate analysis is closer to the calorific value of mixed OFMSW than the values obtained by rest of models. Therefore, this is the best model to be used. From the outcomes of this study it can be realized that the energy recovery from the OFMSW plays a vital role for economical growth of the country. On that account, a systematic approach should be performed in detail before making a decision on such option

  18. Effect of substrate concentration on dry mesophilic anaerobic digestion of organic fraction of municipal solid waste (OFMSW).

    Science.gov (United States)

    Fernández, J; Pérez, M; Romero, L I

    2008-09-01

    The influence of total solid contents during anaerobic mesophilic treatment of the organic fraction of municipal solid waste (MSW) has been studied in this work. The work was performed in batch reactors of 1.7L capacity, during a period of 85-95 days. Two different organic substrate concentrations were studied: 931.1 mgDOC/L (20% TS) and 1423.4 mgDOC/L (30% TS). Experimental results showed that the reactor with 20% total solids content had significantly higher performance. Thus, the startup phase ended at 14 days and the total DOC removal was 67.53%. The startup in reactor R30 ended at 28 days obtaining 49.18% DOC removal. Also, the initial substrate concentration contributed substantially to the amount of methane in the biogas. Hence, the total methane production in the methanogenic phase was 7.01 L and 5.53 L at the end of the experiments for R20 and R30, respectively. PMID:18255282

  19. Biogas from the organic fraction of municipal solid waste: dealing with contaminants for a solid oxide fuel cell energy generator.

    Science.gov (United States)

    Papurello, Davide; Lanzini, Andrea; Leone, Pierluigi; Santarelli, Massimo; Silvestri, Silvia

    2014-11-01

    The present work investigates electricity production using a high efficiency electrochemical generator that employs as fuel a biogas from the dry anaerobic digestion of the organic fraction of municipal solid waste (OFMSW). The as-produced biogas contains several contaminants (sulfur, halogen, organic silicon and aromatic compounds) that can be harmful for the fuel cell: these were monitored via an innovative mass spectrometry technique that enables for in-line and real-time quantification. A cleaning trap with activated carbons for the removal of sulfur and other VOCs contained in the biogas was also tested and monitored by observing the different breakthrough times of studied contaminants. The electrochemical generator was a commercial Ni anode-supported planar Solid Oxide Fuel Cell (SOFC), tested for more than 300 h with a simulated biogas mixture (CH4 60 vol.%, CO2 40 vol.%), directly fed to the anode electrode. Air was added to promote the direct internal conversion of CH4 to H2 and CO via partial oxidation (POx). The initial breakthrough of H2S from the cleaning section was also simulated and tested by adding ∼1 ppm(v) of sulfur in the anode feed; a full recovery of the fuel cell performance after 24h of sulfur exposure (∼1 ppm(v)) was observed upon its removal, indicating the reliable time of anode exposure to sulfur in case of exhausted guard bed.

  20. Insights Into Water-Soluble Organic Aerosol Sources From Carbon-13 Ratios of Size Exclusion Chromatography Fractions

    Science.gov (United States)

    Ruehl, C. R.; Chuang, P. Y.; McCarthy, M. D.

    2008-12-01

    Many sources of organic aerosols have been identified and quantified, and much of this work has used individual (mosty water-insoluble) compounds as tracers of primary sources. However, most organic aerosol cannot be molecularly characterized, and the water-soluble organic carbon (WSOC) in many aerosols is thought to originate from gaseous precursors (i.e., it is secondary in nature). It can therefore be difficult to infer aerosol sources, particularly of background (i.e., aged) aerosols, and of the relatively high-MW component of aerosols. The stable isotope ratios (δ13C) of organic aerosols have been used to distinguish between sources, with lighter values (-30‰ to -25‰) interpreted as having originated from fossil fuel combustion and C4 biogenic emission, and heavier values (-25‰ to - 20‰) indicating a marine or C3 biogenic source. Most published measurements were of either total suspended particulates or PM2.5, however, and it is unknown to what extent these fractions differ from submicron WSOC. We report δ13C for submicron WSOC collected at a variety of sites, ranging from marine to polluted to background continental. Bulk marine organic δ13C ranged from -30.4 to - 27.6‰, slightly lighter than previously published results. This could be due to the elimination of supermicron cellular material or other biogenic primary emissions from the sample. Continental WSOC δ13C ranged from -19.1 to -29.8‰, with heavier values (-19.8 ± 1.0‰) in Oklahoma and lighter values at Great Smoky Mountain National Park in Tennessee (-25.8 ± 2.6‰) and Illinois (-24.5 ± 1.0‰). This likely results from the greater proportional of C3 plant material in the Oklahoma samples. In addition to bulk samples, we used size exclusion chromatography (SEC) to report δ13C of organic aerosols as a function of hydrodynamic diameter. Variability and magnitude of hydrodynamic diameter was greatest at low SEC pH, indicative of the acidic character of submicron WSOC. Tennessee

  1. Structural composition of organic matter in particle-size fractions of soils along a climo-biosequence in the main range of Peninsular Malaysia

    Science.gov (United States)

    Jafarzadeh-Haghighi, Amir Hossein; Shamshuddin, Jusop; Hamdan, Jol; Zainuddin, Norhazlin

    2016-09-01

    Information on structural composition of organic matter (OM) in particle-size fractions of soils along a climo-biosequence is sparse. The objective of this study was to examine structural composition and morphological characteristics of OM in particle-size fractions of soils along a climo-biosequence in order to better understand the factors and processes affecting structural composition of soil organic matter. To explore changes in structural composition of OM in soils with different pedogenesis, the A-horizon was considered for further analyses including particle-size fractionation, solid-state 13C nuclear magnetic resonance (NMR) spectroscopy and scanning electron microscopy (SEM). Due to the increase in the thickness of organic layer with increasing elevation, the A-horizon was situated at greater depth in soils of higher elevation. The relationship between relative abundances of carbon (C) structures and particle-size fractions was examined using principal component analysis (PCA). It was found that alkyl C (20.1-73.4%) and O-alkyl C (16.8-67.7%) dominated particle-size fractions. The proportion of alkyl C increased with increasing elevation, while O-alkyl C showed an opposite trend. Results of PCA confirmed this finding and showed the relative enrichment of alkyl C in soils of higher elevation. Increase in the proportion of alkyl C in 250-2000 μm fraction is linked to selective preservation of aliphatic compounds derived from root litter. SEM results showed an increase in root contribution to the 250-2000 μm fraction with increasing elevation. For the <53 μm fraction, pedogenic process of podzolization is responsible for the relative enrichment of alkyl C. This study demonstrates that changes in structural composition of OM in particle-size fractions of soils along the studied climo-biosequence are attributed to site-specific differences in pedogenesis as a function of climate and vegetation.

  2. Stable (Cu, Mg) and radiogenic (Sr, Nd) isotope fractionation in colloids of boreal organic-rich waters

    International Nuclear Information System (INIS)

    uncertainty, isotopic signatures between truly dissolved and colloidal fractions. Despite the dramatically different structures of the metal-dissolved organic matter (DOM) complexes for Cu2+ and Mg2+, the results of the present work reveal a high homogeneity of stable isotope compositions between colloidal (1 kDa-0.22 μm) and ultra filtered (≤1 kDa) fractions, which is presumably due to the high rate of isotopic exchange between the colloidal and ionic forms of the metals. Variation of radiogenic isotopic composition of Sr among ultra filtered, colloidal and particulate fractions suggests that there is a contribution of atmospheric input to the chemical composition of surface waters and provides certain constraints on the isotopic composition of Sr carried by small organic-rich boreal rivers to the Arctic Ocean. (authors)

  3. Soft X-ray spectromicroscopy study of mineral-organic matter associations in pasture soil clay fractions.

    Science.gov (United States)

    Chen, Chunmei; Dynes, James J; Wang, Jian; Karunakaran, Chithra; Sparks, Donald L

    2014-06-17

    There is a growing acceptance that associations with soil minerals may be the most important overarching stabilization mechanism for soil organic matter. However, direct investigation of organo-mineral associations has been hampered by a lack of methods that can simultaneously characterize organic matter (OM) and soil minerals. In this study, STXM-NEXAFS spectroscopy at the C 1s, Ca 2p, Fe 2p, Al 1s, and Si 1s edges was used to investigate C associations with Ca, Fe, Al, and Si species in soil clay fractions from an upland pasture hillslope. Bulk techniques including C and N NEXAFS, Fe K-edge EXAFS spectroscopy, and XRD were applied to provide additional information. Results demonstrated that C was associated with Ca, Fe, Al, and Si with no separate phase in soil clay particles. In soil clay particles, the pervasive C forms were aromatic C, carboxyl C, and polysaccharides with the relative abundance of carboxyl C and polysaccharides varying spatially at the submicrometer scale. Only limited regions in the soil clay particles had aliphatic C. Good C-Ca spatial correlations were found for soil clay particles with no CaCO3, suggesting a strong role of Ca in organo-mineral assemblage formation. Fe EXAFS showed that about 50% of the total Fe in soils was contained in Fe oxides, whereas Fe-bearing aluminosilicates (vermiculite and Illite) accounted for another 50%. Fe oxides in the soil were mainly crystalline goethite and hematite, with lesser amounts of poorly crystalline ferrihydrite. XRD revealed that soil clay aluminosilicates were hydroxy-interlayered vermiculite, Illite, and kaolinite. C showed similar correlation with Fe to Al and Si, implying a similar association of Fe oxides and aluminosilicates with organic matter in organo-mineral associations. These direct microscopic determinations can help improve understanding of organo-mineral interactions in soils.

  4. Aquatic Therapy for Children

    Science.gov (United States)

    Kucher, Greta; Moore, Kelsey; Rodia, Rachel; Moser, Christy Szczech

    2015-01-01

    Aquatic therapy has long been highlighted in the literature as a potentially powerful therapeutic intervention. This review will highlight basic definitions of aquatic therapy, review salient research, and identify specific diagnoses that may benefit from aquatic therapy. Online resources, blogs, and books that occupational therapists may find…

  5. Phosphorous fractionation in mangrove sediments of Kerala, south west coast of India: the relative importance of inorganic and organic phosphorous fractions

    Digital Repository Service at National Institute of Oceanography (India)

    Resmi, P.; Manju, M.N.; Gireeshkumar, T.R.; Ratheeshkumar, C.S.; Movitha, M.; Shameem, K.; Chandramohanakumar, N.

    act as an efficient trap of organic phosphorous by acting as P sink. The dissolved inorganic phosphate displayed higher concentration in monsoon that could be correlated with higher P leaching from mangrove litter as well as terrigenous input during...

  6. Speciation of organic matter in sandy soil size fractions as revealed by analytical pyrolysis (Py-GC/MS) and FT-IR spectroscopy

    Science.gov (United States)

    Jiménez-Morillo, Nicasio T.; González-Vila, Francisco J.; Jordán, Antonio; Zavala, Lorena M.; de la Rosa, José M.; González-Pérez, José A.

    2015-04-01

    This research deals with the assessment of organic matter structural differences in soil physical fractions before and after lipid extractions. Soil samples were collected in sandy soils, Arenosols (WRB 2006) from the Doñana National Park (SW Spain) under different vegetation cover: cork oak (Quercus suber, QS), eagle fern (Pteridium aquilinum, PA), pine (Pinus pinea, PP) and rockrose (Halimium halimifolium, HH). Two size fractions; coarse (C: 1-2 mm) and fine (F: 0.05-0.25 mm) were studied from each soil. . In addition, the two fractions from each soil were exhaustively Soxhlet extracted with a Dichlorometane-Methanol (3:1) mixture to obtain the lipid-free fractions (LF) from each size fraction (LFC and LFF). The composition of the organic matter at a molecular level in the different soil fractions was approached by analytical pyrolysis (Py-GC/MS) and FT-IR spectroscopy. These techniques are complementary and have been found suitable for the structural characterization of complex organic matrices (Moldoveanu, 1998; Piccolo and Stevenson, 1982); whereas Py-GC/MS provides detailed structural information of individual compounds present and a finger-printing of soil organic matter, FT-IR is informative about major functional groups present. The advantages of these techniques are well known: no need for pretreatment are fast to perform, highly reproducible and only small amount of samples are needed. Soil size fractions show contrasting differences in organic matter content (C 4-7 % and F > 40 %) and conspicuous differences were found in the pyrolysis products released by the fractions studied. The main families of pyrolysis compounds have well defined macromolecular precursors, such as lignin, polypeptides, polysaccharides and lipids (González-Vila et al., 2001). The C fractions yield higher relative abundance of lignin and polysaccharide derived pyrolysis compounds. Regarding the differences in the soil organic matter as affected by the different vegetation covers

  7. [Effects of land cover change on soil organic carbon and light fraction organic carbon at river banks of Fuzhou urban area].

    Science.gov (United States)

    Zeng, Hong-Da; Du, Zi-Xian; Yang, Yu-Sheng; Li, Xi-Bo; Zhang, Ya-Chun; Yang, Zhi-Feng

    2010-03-01

    By using Vario EL III element analyzer, the vertical distribution characteristics of soil organic carbon (SOC) and light-fraction organic carbon (LFOC) in the lawn, patch plantation, and reed wetland at river banks of Fuzhou urban area were studied in July 2007. For all the three land cover types, the SOC and LFOC contents were the highest in surface soil layer, and declined gradually with soil depth. Compared with reed wetland, the lawn and patch plantation had higher SOC and LFOC contents in each layer of the soil profile (0-60 cm), and the lawn had significantly higher contents of SOC and LFOC in 0-20 cm soil layer, compared with the patch plantation. After the reed wetland was converted into lawn and patch plantation, the SOC stock in the soil profile was increased by 94.8% and 72.0%, and the LFOC stock was increased by 225% and 93%, respectively. Due to the changes of plant species, plant density, and management measure, the conversion from natural wetland into human-manipulated green spaces increased the SOC and LFOC stocks in the soil profile, and improved the soil quality. Compared with the SOC, soil LFOC was more sensitive to land use/cover change, especially for those in 0-20 cm soil layer.

  8. Effect of organic loading rate on the performance of two-stage anaerobic digestion of the organic fraction of municipal solid waste (OFMSW).

    Science.gov (United States)

    Rodríguez-Pimentel, Reyna I; Rodríguez-Pérez, Suyen; Monroy-Hermosillo, Oscar; Ramírez-Vives, Florina

    2015-01-01

    Two-stage anaerobic digestion of the organic fraction of municipal solid waste (OFMSW) was carried out: hydrolysis and acidogenesis in a continuous anaerobic hydrolytic leach bed (AHLB) reactor loaded at different rates (Bv = 3.8-7 gVSSL⁻¹d⁻¹) and methanogenesis of leachates, diluted with municipal wastewater in an upflow anaerobic sludge blanket (UASB) reactor at organic loading rates of 6.6-13 gCODLr⁻¹d⁻¹. In the AHLB reactor, 51-76% and 58-71% volatile solids and chemical oxygen demand (COD) removal efficiencies were obtained. During the hydrolysis and acidogenesis phases, the effluents were at pH 4.93, the leachate had a volatile fatty acids concentration of 35 g/L and the biogas was composed only of CO₂. The average methane production in the UASB in the load of 4.4 gVS L⁻¹ d⁻¹ in the AHLB was 3.32 LCH4Lr⁻¹d⁻¹ (yCH4 = 80%), with COD removal efficiency of 95% and methane yield 279 LCH4KgVS⁻¹OFMSW degraded. PMID:26204070

  9. Dissolved organic carbon reduces uranium bioavailability and toxicity. 1. Characterization of an aquatic fulvic acid and its complexation with uranium[VI].

    Science.gov (United States)

    Trenfield, Melanie A; McDonald, Suzanne; Kovacs, Krisztina; Lesher, Emily K; Pringle, Jennifer M; Markich, Scott J; Ng, Jack C; Noller, Barry; Brown, Paul L; van Dam, Rick A

    2011-04-01

    Fulvic acid (FA) from a tropical Australian billabong (lagoon) was isolated with XAD-8 resin and characterized using size exclusion chromatography, solid state cross-polarization magic angle spinning, 13C nuclear magnetic resonance spectroscopy, elemental analysis, and potentiometric acid-base titration. Physicochemical characteristics of the billabong FA were comparable with those of the Suwannee River Fulvic Acid (SRFA) standard. The greater negative charge density of the billabong FA suggested it contained protons that were more weakly bound than those of SRFA, with the potential for billabong water to complex less metal contaminants, such as uranium (U). This may subsequently influence the toxicity of metal contaminants to resident freshwater organisms. The complexation of U with dissolved organic carbon (DOC) (10 mg L(-1)) in billabong water was calculated using the HARPHRQ geochemical speciation model and also measured using flow field-flow fractionation combined with inductively coupled plasma mass-spectroscopy. Agreement between both methods was very good (within 4% as U-DOC). The results suggest that in billabong water at pH 6.0, containing an average DOC of 10 mg L(-1) and a U concentration of 90 μg L(-1), around 10% of U is complexed with DOC. PMID:21351802

  10. Modul.LES: a multi-compartment, multi-organism aquatic life support system as experimental platform for research in ∆g

    Science.gov (United States)

    Hilbig, Reinhard; Anken, Ralf; Grimm, Dennis

    In view of space exploration and long-term satellite missions, a new generation of multi-modular, multi-organism bioregenerative life support system with different experimental units (Modul.LES) is planned, and subunits are under construction. Modul.LES will be managed via telemetry and remote control and therefore is a fully automated experimental platform for different kinds of investigations. After several forerunner projects like AquaCells (2005), C.E.B.A.S. (1998, 2003) or Aquahab (OHB-System AG the Oreochromis Mossambicus Eu-glena Gracilis Aquatic Habitat (OmegaHab) was successfully flown in 2007 in course of the FOTON-M3 Mission. It was a 3 chamber controlled life support system (CLSS), compris-ing a bioreactor with the green algae Euglena gracilis, a fish chamber with larval cichlid fish Oreochromis mossambicus and a filter chamber with biodegrading bacteria. The sensory super-vision of housekeeping management was registered and controlled by telemetry. Additionally, all scientific data and videos of the organisms aboard were stored and sequentially transmitted to relay stations. Based on the effective performance of OmegaHab, this system was chosen for a reflight on Bion-M1 in 2012. As Bion-M1 is a long term mission (appr. 4 weeks), this CLSS (OmegaHab-XP) has to be redesigned and refurbished with enhanced performance. The number of chambers has been increased from 3 to 4: an algae bioreactor, a fish tank for adult and larval fish (hatchery inserted), a nutrition chamber with higher plants and crustaceans and a filter chamber. The OmegaHab-XP is a full automated system with an extended satellite downlink for video monitoring and housekeeping data acquisition, but no uplink for remote control. OmegaHab-XP provides numerous physical and chemical parameters which will be monitored regarding the state of the biological processes and thus enables the automated con-trol aboard. Besides the two basic parameters oxygen content and temperature, products of the

  11. Mutagenicity and in vivo toxicity of combined particulate and semivolatile organic fractions of gasoline and diesel engine emissions.

    Science.gov (United States)

    Seagrave, JeanClare; McDonald, Jacob D; Gigliotti, Andrew P; Nikula, Kristen J; Seilkop, Steven K; Gurevich, Michael; Mauderly, Joe L

    2002-12-01

    Exposure to engine emissions is associated with adverse health effects. However, little is known about the relative effects of emissions produced by different operating conditions, fuels, or technologies. Rapid screening techniques are needed to compare the biological effects of emissions with different characteristics. Here, we examined a set of engine emission samples using conventional bioassays. The samples included combined particulate material and semivolatile organic compound fractions of emissions collected from normal- and high-emitter gasoline and diesel vehicles collected at 72 degrees F, and from normal-emitter groups collected at 30 degrees F. The relative potency of the samples was determined by statistical analysis of the dose-response curves. All samples induced bacterial mutagenicity, with a 10-fold range of potency among the samples. Responses to intratracheal instillation in rats indicated generally parallel rankings of the samples by multiple endpoints reflecting cytotoxic, inflammatory, and lung parenchymal changes, allowing selection of a more limited set of parameters for future studies. The parameters selected to assess oxidative stress and macrophage function yielded little useful information. Responses to instillation indicated little difference in potency per unit of combined particulate material and semivolatile organic compound mass between normal-emitter gasoline and diesel vehicles, or between emissions collected at different temperatures. However, equivalent masses of emissions from high-emitter vehicles of both types were more potent than those from normal-emitters. While preliminary in terms of assessing contributions of different emissions to health hazards, the results indicate that a subset of this panel of assays will be useful in providing rapid, cost-effective feedback on the biological impact of modified technology.

  12. Long Term Effect of Manuring, Fertilization and Cropping on Soil Organic Carbon and Nitrogen fractions of rainfed Alfisols.

    Science.gov (United States)

    Ganapathi; A, Shankar, M.; N, Gajanana, G.; K, Ramachandrappa, B.; Somashekara., K.,

    2009-04-01

    Soil samples collected from different treatment of 30 years long term experiment located at GKVK, Bangalore, Karnataka, were analyzed for Soil Organic Carbon (SOC) content and distribution of N fractions. Results indicated that samples obtain from the treatments involving continuous use of FYM alone and FYM integrated with NPK fertilizers recorded higher values with respect to NH4+-N , NO3--N, fixed NH4+-N hydrolysable NH4+- N, hexosamine -N, amino acid N, available and total N content compared to the treatments involving only NPK fertilizers or without any fertilizer or organic (control). Similarly highest SOC (0.58 per cent) was recorded by the treatment involving application of FYM @ 10 t / ha followed by the treatments involving FYM @ 10 t / ha + RDF, FYM @ 10 t / ha + 50 %. RDF and only RDF which recorded the SOC of 0.54, 0.53 and 0.37 per cent respectively. In respect of Fulvic Acid (FA) and Humic acid (HA) in soil, the highest (0.23 per cent) Fulvic Acid (FA) was recorded in the treatments which receive FYM @ 10 t / ha compared to all other treatments and the lowest Fulvic Acid (0.14 per cent) was recorded in receiving only RDF. Similarly Humic Acid carbon was found to be highest (0.34 per cent) in the treatment receiving FYM @ 10 t / ha and lowest Humic Acid content (0.195 per cent) was recorded in recommended NPK fertilizers. In respect to per cent Humic Acid and Fulvic Acid in humus, highest Fulvic Acid (77.2 per cent) in humus was recorded in control and lowest Fulvic Acid (54.6 per cent) was noticed in treatment receiving FYM @ 10 t / ha + recommended NPK fertilizers, while highest (45.3 per cent) Humic Acid in humus was recorded in FYM @ 10 t / ha + recommended NPK and lowest (22.8 per cent) was noticed in control.

  13. Economic and environmental sustainability of an AnMBR treating urban wastewater and organic fraction of municipal solid waste.

    Science.gov (United States)

    Pretel, R; Moñino, P; Robles, A; Ruano, M V; Seco, A; Ferrer, J

    2016-09-01

    The objective of this study was to evaluate the economic and environmental sustainability of a submerged anaerobic membrane bioreactor (AnMBR) treating urban wastewater (UWW) and organic