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Bioanalytical and instrumental screening of the uptake of sediment-borne, dioxin-like compounds in roach (Rutilus rutilus) Full text
2016
Eichbaum, Kathrin | Brinkmann, Markus | Nuesser, Leonie | Buchinger, Sebastian | Reifferscheid, Georg | Codling, Garry | Jones, Paul | Giesy, John P. | Hecker, Markus | Hollert, Henner
To examine the uptake of dioxin-like compounds (DLCs), common roaches (Rutilus rutilus) were exposed for 28 days to differently contaminated sediments from two major European rivers in a purpose-built facility. Dietary transfer of DLCs was investigated by exposing fish to sediments inoculated or non-inoculated with black worms (Lumbriculus variegatus). Dioxin-like polychlorinated biphenyls (DL-PCBs), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), measured via high-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS) in sediments and whole fish, were used to calculate toxicity equivalent quotients (TEQs). TEQs were compared with biological toxicity equivalent quotients (BEQs) determined via the 7-ethoxyresorufin-O-deethylase (EROD) assay, performed with mammalian (H4IIE) and fish (RTL-W1) liver cell lines. TEQs and BEQs indicated an uptake of sediment-borne DLCs by roach, which was independent of sediment contamination levels, but rather reflected sediment-specific characteristics. For most sediment treatments, DLC uptake did not increase with time. Highest congener-specific uptake (DL-PCB 123) was 10-fold compared to control. Exposure to worm-inoculated sediment of highest overall DLC contamination caused a 2-fold (TEQ and H4IIE BEQ) greater uptake of DLCs by fish compared to the respective non-inoculated treatment. H4IIE cells showed the greatest sensitivity (0.37 ± 0.25 pM TCDD) and the strongest correlation with TEQs (r ² = 0.79), hence, they seem to be best suited for DLC screening of sediments and biota, amended by compound-specific instrumental analysis if required.
Show more [+] Less [-]Measurement of p-nitrophenyl acetate esterase activity (EA), total antioxidant capacity (TAC), total oxidant status (TOS) and acetylcholinesterase (AChE) in gills and digestive gland of Mytilus galloprovincialis exposed to binary mixtures of Pb, Cd and Cu Full text
2016
Franco-Martinez, Lorena | Romero, Diego | García-Navarro, José A. | Tecles, Fernando | Teles, Mariana | Tvarijonaviciute, Asta
The aims of the present work were (1) to evaluate oxidative stress biomarkers and AChE in two tissues of wild mussel (Mytilus galloprovincialis) of high biochemical activity and accumulation capacity (gills and digestive gland) and (2) to study the behaviour of these biomarkers in presence of heavy metals. For this, EA, TOS, TAC and AChE were measured in tissues of mussels exposed to binary combination of Pb, Cd and Cu. Mussels (n = 36) were exposed to one of the binary mixtures of Pb (1000 μg L⁻¹), Cd (100 μg L⁻¹) and Cu (100 μg L⁻¹) for 7 days, under controlled conditions. Gills and digestive gland were extracted and frozen at −80 °C until analysis. The automatic methods employed for the measurement of EA, TAC, TOS and AChE in M. galloprovincialis revealed higher levels of these biomarkers in digestive gland than gills. Study results suggest that gills would be the tissue of election for study oxidative stress markers, whereas digestive tissue should be selected for AChE measurements in case of evaluation of combined metal toxicity in mussels.
Show more [+] Less [-]Phosphorus adsorption on natural sediments with different pH incorporating surface morphology characterization Full text
2016
Huang, Lei | Fang, Hongwei | He, Guojian | Chen, Minghong
Sediment samples from University Lake (U.L.) and Anacostia River (A.R.) were collected to study the phosphorus (P) adsorption with pH at 3.65, 4.75, and 5.65. The surface micro-morphology and pore structures of sediment particles were obtained using a scanning electron microscopy and gas adsorption method, respectively. Fourier analysis was then applied to approximate the surface morphology, which was incorporated into the Langmuir isotherm to directly derive the model parameters for P adsorption simulation. Meanwhile, an empirical function of pH was introduced to represent the pH effect on P adsorption. A stronger P adsorption was observed for the A.R. sediment due to the more clay minerals, smaller median diameter, and a greater percentage of large pores, and the increasing pH resulted in a decrease of adsorption equilibrium constant as well as the P adsorption capacity, which was well reproduced by the adsorption isotherms. This study would benefit the mechanism study of the interactions between sediment particles and pollutants, providing references for understanding the pollutants’ transport in aqueous systems.
Show more [+] Less [-]Spatial and temporal trends of ozone distribution in the Jizerské hory Mountains of the Czech Republic Full text
2016
Hůnová, Iva | Stoklasová, Petra | Schovánková, Jana | Kulasová, Alena
We present results of the 5-year monitoring of ambient O₃ concentrations in a Central European medium altitude mountain forested area. O₃ levels were measured at 11 sites between 714 and 1000 m a.s.l. in 2006–2010 vegetation seasons using Ogawa diffusive samplers. Our results reveal that O₃ exposure in the Jizerské hory Mts. was relatively high and comparable with polluted sites in Southern Europe and in higher altitudes. O₃ concentrations differed significantly between individual sites and in individual years. O₃ concentrations showed clear dependence on altitude at sites with similar aspect. Its gradient for the entire 5-year period under review equaled 3.5 ppb/100 m of altitude, ranging between nearly 5 ppb/100 m of altitude in 2006 and nearly 3 ppb/100 m of altitude in 2010. O₃ concentrations at the site with northern aspect were consistently significantly lower than at the site at similar altitude with southern aspect. O₃ concentrations measured at the forest edge were consistently lower than those measured at the same site but at the forest clearing. It is evident that the macro-setting of the O₃ monitoring site is crucial for obtaining reliable results with high representativeness for the area.
Show more [+] Less [-]An integrated optimization method for river water quality management and risk analysis in a rural system Full text
2016
Liu, J. | Li, Y. P. | Huang, G. H. | Zeng, X. T. | Nie, S.
In this study, an interval-stochastic-based risk analysis (RSRA) method is developed for supporting river water quality management in a rural system under uncertainty (i.e., uncertainties exist in a number of system components as well as their interrelationships). The RSRA method is effective in risk management and policy analysis, particularly when the inputs (such as allowable pollutant discharge and pollutant discharge rate) are expressed as probability distributions and interval values. Moreover, decision-makers’ attitudes towards system risk can be reflected using a restricted resource measure by controlling the variability of the recourse cost. The RSRA method is then applied to a real case of water quality management in the Heshui River Basin (a rural area of China), where chemical oxygen demand (COD), total nitrogen (TN), total phosphorus (TP), and soil loss are selected as major indicators to identify the water pollution control strategies. Results reveal that uncertainties and risk attitudes have significant effects on both pollutant discharge and system benefit. A high risk measure level can lead to a reduced system benefit; however, this reduction also corresponds to raised system reliability. Results also disclose that (a) agriculture is the dominant contributor to soil loss, TN, and TP loads, and abatement actions should be mainly carried out for paddy and dry farms; (b) livestock husbandry is the main COD discharger, and abatement measures should be mainly conducted for poultry farm; (c) fishery accounts for a high percentage of TN, TP, and COD discharges but a has low percentage of overall net benefit, and it may be beneficial to cease fishery activities in the basin. The findings can facilitate the local authority in identifying desired pollution control strategies with the tradeoff between socioeconomic development and environmental sustainability.
Show more [+] Less [-]Do morphometric parameters and geological conditions determine chemistry of glacier surface ice? Spatial distribution of contaminants present in the surface ice of Spitsbergen glaciers (European Arctic) Full text
2016
Lehmann, Sara | Gajek, Grzegorz | Chmiel, Stanisław | Polkowska, Żaneta
The chemism of the glaciers is strongly determined by long-distance transport of chemical substances and their wet and dry deposition on the glacier surface. This paper concerns spatial distribution of metals, ions, and dissolved organic carbon, as well as the differentiation of physicochemical parameters (pH, electrical conductivity) determined in ice surface samples collected from four Arctic glaciers during the summer season in 2012. The studied glaciers represent three different morphological types: ground based (Blomlibreen and Scottbreen), tidewater which evolved to ground based (Renardbreen), and typical tidewater glacier (Recherchebreen). All of the glaciers are functioning as a glacial system and hence are subject to the same physical processes (melting, freezing) and the process of ice flowing resulting from the cross-impact force of gravity and topographic conditions. According to this hypothesis, the article discusses the correlation between morphometric parameters, changes in mass balance, geological characteristics of the glaciers and the spatial distribution of analytes on the surface of ice. A strong correlation (r = 0.63) is recorded between the aspect of glaciers and values of pH and ions, whereas dissolved organic carbon (DOC) depends on the minimum elevation of glaciers (r = 0.55) and most probably also on the development of the accumulation area. The obtained results suggest that although certain morphometric parameters largely determine the spatial distribution of analytes, also the geology of the bed of glaciers strongly affects the chemism of the surface ice of glaciers in the phase of strong recession.
Show more [+] Less [-]Serum concentrations of PCBs and OCPs among prepubertal Korean children Full text
2016
Park, Su Hyun | Hong, Young Sun | Ha, Eun-Hee | Park, Hyesook
Although children are more vulnerable than adults to environmental hazards, due to their physiological and behavioral characteristics, few studies have assessed their internal exposure to persistent organic pollutants (POPs). The objective of this study was to determine the serum levels of certain polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) among pre-pubertal children in Korea and examine their variation with age and gender. We analyzed a total of 51 POPs in 214 children (age range, 7–9 years), using data from the Ewha Birth and Growth Cohort Study. To examine change over time, POP concentrations were measured at both 7 and 9 years of age in a sub-cohort of 26 children. The median and interquartile range (IQR, 25th to 75th percentiles) data for the sum of PCB congeners was 26.44 ng/g lipid (18.27–37.63 ng/g lipid). The median (IQR) concentration for the sum of OCPs was 74.82 ng/g lipid (51.11–112.45 ng/g lipid). Our results showed significant increases in serum concentrations of total PCBs with age (p = 0.0001), no gender dependence of total PCBs (p = 0.38) and total OCPs (p = 0.12), and strong correlations between individual POPs. Childhood exposure to POPs was relatively low compared to other studies carried out in different countries. However, even though the use of POPs has been banned since 2001, our results indicated that children in the general population are still exposed to various POPs. Because long-term, low-level exposure to POPs in the general population remains a concern for human health, future research should examine major routes of exposure and identification of risk factors.
Show more [+] Less [-]Effect of freeze-thaw cycles and 4-nonylphenol on cellular energy allocation in the freeze-tolerant enchytraeid Enchytraeus albidus Full text
2016
Patrício-Silva, Ana L. | Amorim, Mónica J. B.
Due to climate change and intense anthropogenic activity, organisms from cold regions are often exposed to combined effects of temperature fluctuations and contaminants. In this investigation, we assessed the lipid, protein, and carbohydrate energy budgets; the energy available (Ea); consumed (Ec); and cellular energy allocation (CEA) of the freeze-tolerant Enchytraeus albidus, when exposed to sublethal concentrations of 4-nonylphenol (a lipophilic contaminant) for 7 days, followed by exposure to different temperature regimes (continuous 2 °C, continuous −4 °C, and daily freeze-thaw cycles (FTC) (2 to −4 °C) for additional 10 days. Results showed that a pre-exposure to 4-nonylphenol (4-NP) induced important changes in the worms’ energy budgets and CEA and increased mortality with most severe effects observed for the FTC events. For FTC, lipids were the most accumulated energy source, whereas during freezing (−4 °C), proteins were the most used. FTC caused the highest Ec, indicating the higher energy requirements for organisms when shifting between freezing and thawing events. This is also in line with the higher mortality observed in FTC compared to continuous −4 °C or 2 °C. Worms exposed to continuous freezing presented relatively stable and positive levels of Ea and low levels of Ec, possibly related with the decrease in metabolism.
Show more [+] Less [-]Effect of operation parameters on the flux stabilization of gravity-driven membrane (GDM) filtration system for decentralized water supply Full text
2016
Tang, Xiaobin | Ding, An | Qu, Fangshu | Jia, Ruibao | Chang, Haiqing | Cheng, Xiaoxiang | Liu, Bin | Li, Guibai | Liang, Heng
A pilot-scale gravity-driven membrane (GDM) filtration system under low gravitational pressure without any pre-treatment, backwash, flushing, or chemical cleaning was carried out to investigate the effect of operation parameters (including operation pressure, aeration mode, and intermittent filtration) on the effluent quality and permeability development. The results revealed that GDM system exhibited an efficient performance for the removal of suspended substances and organic compounds. The stabilization of flux occurred and the average values of stable flux were 6.6, 8.1, and 8.6 Lm⁻² h⁻¹ for pressures of 65, 120, and 200 mbar, respectively. In contrast, flux stabilization was not observed under continuous and intermittent aeration conditions. However, aeration (especially continuous aeration) was effective to improve flux and alleviate membrane fouling during 1-month operation. Moreover, intermittent filtration would influence the stabilization of permeate flux, resulting in a higher stable flux (ranging from 6 to 13 Lm⁻² h⁻¹). The stable flux significantly improved with the increase of intermittent period. Additionally, GDM systems exhibited an efficient recovery of flux after simple physical cleaning and the analyses of resistance reversibility demonstrated that most of the total resistance was hydraulic reversible resistance (50–75 %). Therefore, it is expected that the results of this study can develop strategies to increase membrane permeability and reduce energy consumption in GDM systems for decentralized water supply.
Show more [+] Less [-]Evaluation of the microbiological quality of reclaimed water produced from a lagooning system Full text
2016
Fernandez-Cassi, X. | Silvera, C. | Cervero-Aragó, S. | Rusiñol, M. | Latif-Eugeni, F. | Bruguera-Casamada, C. | Civit, S. | Araujo, R. M. | Figueras, M. J. | Girones, R. | Bofill-Mas, S.
The use of lagooning as a complementary natural method of treating secondary effluents of wastewater treatment plants has been employed as an affordable and easy means of producing reclaimed water. However, using reclaimed water for some purposes, for example, for food irrigation, presents some risks if the effluents contain microbial pathogens. Classical bacterial indicators that are used to assess faecal contamination in water do not always properly indicate the presence of bacterial or viral pathogens. In the current study, the presence of faecal indicator bacteria (FIB), heterotrophic bacterial counts (HBC), pathogens and opportunistic pathogens, such as Legionella spp., Aeromonas spp., Arcobacter spp., free-living amoeba (FLA), several viral indicators (human adenovirus and polyomavirus JC) and viral pathogens (noroviruses and hepatitis E virus) were analysed for 1 year in inlet and outlet water to assess the removal efficiency of a lagooning system. We observed 2.58 (1.17–4.59) and 1.65 (0.15–3.14) log reductions in Escherichia coli (EC) and intestinal enterococci (IE), respectively, between the inlet and outlet samples. Genomic copies of the viruses were log reduced by 1.18 (0.24–2.93), 0.64 (0.12–1.97), 0.45 (0.04–2.54) and 0.72 (0.22–2.50) for human adenovirus (HAdV), JC polyomavirus (JCPyV) and human noroviruses (NoV GI and GII), respectively. No regrowth of opportunistic pathogens was observed within the system. FLA, detected in all samples, did not show a clear trend. The reduction of faecal pathogens was irregular with 6 out of 12 samples and 4 out of 12 samples exceeding the EC and IE values, specified in the Spanish legislation for reclaimed water (RD 1620/2007). This data evidences that there is a need for more studies to evaluate the removal mechanisms of lagooning systems in order to optimize pathogen reduction. Moreover, surveillance of water used to irrigate raw edible vegetables should be conducted to ensure the fulfilment of the microbial requirements for the production of safe reclaimed water.
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