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301.
The waste input and the process technology of waste incineration plants appear to have a great influence on bottom ash quality. To better understand how these parameters can affect the characteristics of residues, bottom ash from six plants were tested and compared in this study. Bottom ash physico-chemical characteristics were investigated by chemical analyses, and leaching tests. In order to understand their long-term behavior, accelerated ageing experiments and biodegradation tests were also performed. The whole analyses gave complementary information. It was shown that the six samples do have different properties. Waste inputs have a great influence on Cl and S content in bottom ash, as well as on the Ca/Si ratio. The importance of this ratio on the carbonation process has been demonstrated. Combustion parameters have an influence on the quantity and mobility of the residual organic matter.  相似文献   
302.
Ecological (biological and hydrochemical assessment) and hydrogeological (vulnerability and pollution risk mapping) tools have been combined to assess the ecological quality and hydrogeological vulnerability of an agricultural river basin. In addition, the applicability of the recently developed vulnerability assessment approach (COP method) in the particular environmental conditions was tested by comparing its results with hydroecological assessment tools (i.e., pollution metrics). Five sampling sites were selected and sampled for benthic macroinvertebrates and physicochemical variables during summer and spring. Overall, sites ranged from moderate to poor ecological quality. The results illustrated that 26% of the study area was of moderate pollution risk, while 65% was classified as of low and very low risk zones. However, the higher elevation zones where calcareous rock formations are encountered presented moderate to high pollution risk that was accredited by the ecological quality assessment. Pollution metrics facilitated from hydrochemical analysis indicated a significant association with groundwater vulnerability, thus validating vulnerability and risk estimations. This study indicated that the particular groundwater pollution risk mapping methodology and the water quality assessment indices can be well combined to provide an integrated evaluation tool at a catchment scale.  相似文献   
303.
Twenty-three soft drink samples (i.e., four pineapple-based fruit drinks, eight citrus-based fruit juices, one soya-based drink, three cola carbonated drinks, one apple-based fruit drink, and six cocktail fruit drinks) were randomly purchased from retail outlets in an urban market in Accra and analyzed for the concentrations of iron, cobalt, cadmium, zinc, lead, and copper using flame atomic absorption spectrometry. The mean concentration of iron and cadmium were 0.723?±?0.448 mg/L and 0.032?±?0.012 mg/L, respectively. The mean cobalt concentration was 0.071?±?0.049 mg/L, while the mean Zn concentration in the samples was 0.060?±?0.097 mg/L. The mean concentrations of Pb and Cu in the fruit juice samples were 0.178?±?0.091 mg/L and 0.053?±?0.063 mg/L respectively. About 78 % of the samples exceeded the United States Environmental Protection Agency (USEPA) maximum contaminant level of 0.3 mg/L prescribed for iron, whereas all the samples exceeded the USEPA maximum contaminant level of 0.005 mg/L prescribed for cadmium. About 91 % of the samples exceeded the EU maximum contaminant level prescribed for lead insoft drinks.  相似文献   
304.
Environmental Science and Pollution Research - The presence of pharmacologically active compounds (PhACs) in surface waters poses an environmental risk of chronic exposure to nontarget organisms,...  相似文献   
305.
Understanding whether assemblages of species respond more strongly to bottom-up (availability of trophic resources or habitats) or top-down (predation pressure) processes is important for effective management of resources and ecosystems. We determined the relative influence of environmental factors and predation by humans in shaping the density, biomass, and species richness of 4 medium-bodied (10–40 cm total length [TL]) coral reef fish groups targeted by fishers (mesopredators, planktivores, grazer and detritivores, and scrapers) and the density of 2 groups not targeted by fishers (invertivores, small fish ≤10 cm TL) in the central Philippines. Boosted regression trees were used to model the response of each fish group to 21 predictor variables: 13 habitat variables, 5 island variables, and 3 fishing variables (no-take marine reserve [NTMR] presence or absence, NTMR size, and NTMR age). Targeted and nontargeted fish groups responded most strongly to habitat variables, then island variables. Fishing (NTMR) variables generally had less influence on fish groups. Of the habitat variables, live hard coral cover, structural complexity or habitat complexity index, and depth had the greatest effects on density, biomass, and species richness of targeted fish groups and on the density of nontargeted fishes. Of the island variables, proximity to the nearest river and island elevation had the most influence on fish groups. The NTMRs affected only fishes targeted by fishers; NTMR size positively correlated with density, biomass, and species richness of targeted fishes, particularly mesopredatory, and grazing and detritivorous fishes. Importantly, NTMRs as small as 15 ha positively affected medium-bodied fishes. This finding provides reassurance for regions that have invested in small-scale community-managed NTMRs. However, management strategies that integrate sound coastal land-use practices to conserve adjacent reef fish habitat, strategic NTMR placement, and establishment of larger NTMRs will be crucial for maintaining biodiversity and fisheries.  相似文献   
306.
Mixing inside an anaerobic digester is often continuous and is not actively controlled. The selected mixing regime can however affect both gas production and the energy efficiency of the biogas plant. This study aims to evaluate these effects and compare three different mixing regimes, 150 RPM and 25 RPM continuous mixing and minimally intermittent mixing for both digestion of fresh substrate and post-digestion of the organic fraction of municipal solid waste. The results show that a lower mixing intensity leads to a higher biogas production rate and higher total biogas production in both cases. 25 RPM continuous mixing and minimally intermittent mixing resulted in similar biogas production after process stabilization, while 150 RPM continuous mixing resulted in lower production throughout the experiment. The lower gas production at 150 RPM could not be explained by the inhibition of volatile fatty acids. Cumulative biogas production until day 31 was 295 ± 2.9, 317 ± 1.9 and 304 ± 2.8 N ml/g VS added during digestion of fresh feed and 113 ± 1.3, 134 ± 1.1 and 130 ± 2.3 N ml/g VS added during post digestion for the 150 RPM, 25 RPM and minimally mixed intensities respectively. As well as increasing gas production, optimal mixing can improve the energy efficiency of the anaerobic digestion process.  相似文献   
307.
On October 12, 2012, the provincial public health directorate of Salzburg reported a suspected norovirus (NV) outbreak among guests of a wedding–reception. The investigation aimed to confirm the causative agent, to identify the mode of transmission and to implement appropriate preventive measures. A probable outbreak case was defined as a wedding guest with diarrhoea or vomiting with disease onset from 7 to 10 October 2012 and who consumed food at the wedding dinner prepared by a hotel in the province Salzburg on 6 October 2012. A confirmed outbreak case fulfilled the criteria of a probable outbreak case and had a laboratory-confirmed NV infection. We conducted a cohort-investigation among the wedding guests. The case definitions were fulfilled in 26 wedding guests (25 %) including 2 confirmed cases. Females were 3.2 times more likely to develop disease (95 % CI 1.4–7.2) as compared to males. A mushroom dish was found to be associated with disease risk among females (risk ratio 2.3, 95 % CI 1.2–4.3). Two of 2 tested case-patients and 6 of 14 kitchen workers tested were positive for NV GII.4 Sydney. One kitchen staff-member worked during the wedding dinner despite diarrhoea. No food safety training was documented for the employees and the kitchen staff’s restroom was lacking operational facilities for hand hygiene. We report the first investigated outbreak due to GII.4 Sydney, which was likely due to a symptomatic kitchen worker. Gender-specific eating behaviour may have posed female guests at higher risk of NV infection.  相似文献   
308.
Initial values and windows of competence together with a biological test system are introduced to identify soil contaminations. Theinitial values are defined as the amount of extract equivalent to a defined amount of soil (gramm soil equivalent) and the same amount of test medium. This is equivalent to a complete replacement of the test medium with the soil being tested. Theeffect limits should be at least the double standard deviation of the blank values. Based on the values found when testing uncontaminated soils, a higher threshold value has to be established for some test systems. Should no relationship be found to a standard test medium (e.g. agar as a matrix in the Ames assay), the so-calledwindow of competence is defined. Within this window no natural response is found when ex amining uncontaminated soil. For mutagenicity tests, the double spontaneous reversion rate (reversion coefficient of 2) as related o the blank sample is evaluated as the effect limit.  相似文献   
309.
Concentrations and air-water gas exchange of polychlorinated biphenyls (PCBs) and hexachlorocyclohexanes (HCHs) were determined in nine paired air and water samples. The samples were collected monthly in the Kattegat Sea between December 1998 and November 1999. Average fugacity and flux values indicated that PCBs were oversaturated in the water, while HCHs were net deposited. Variations were large over the year, especially during spring and summer. Air parcel back trajectories suggested that air concentrations over the Kattegat Sea are largely dependent of air mass origin. Seasonal trends were detected for airborne HCHs and for PCBs in water. The air and water enantiomeric compositions of alpha-HCH indicated that a larger portion of alpha-HCH in air originated from the underlying water during summer than during winter.  相似文献   
310.
Regional differences in chemical fate model outcome   总被引:3,自引:0,他引:3  
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