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461.
PM10-bound polycyclic aromatic hydrocarbons (PAHs) in the Greater Area of Athens, Greece 总被引:2,自引:0,他引:2
Polycyclic aromatic hydrocarbons (PAHs) associated to ambient PM10 were determined at four sites within the Greater Athens Area (GAA), Greece, during the period May 2001-June 2002. Daily average PM10 samples were collected using reference samplers installed in two urban locations (Maroussi, MAR and Aristotelous, ARI), a mixed urban-industrial location (Elefsina, ELE), and a background location (Thracomacedones, THR). Spatial and temporal variation of ambient PAH levels and possible relationships with conventional air pollutants and meteorological parameters were investigated. Moreover, source identification was attempted using diagnostic ratios. The PAH concentrations observed in this study, even in downtown Athens, were towards the lowest end of the range of values reported for other European urban locations. The mean concentration of the well known carcinogen B[alpha]Py was at all four sites below the proposed value of 1 ng m-3 (annual average assessment threshold). Automobile traffic was identified as the major PAH source in the GAA exhibiting greatest contribution in the urban sites. 相似文献
462.
The evaluation of electrical energy per order (E(Eo)) for photooxidative decolorization of four textile dye solutions by the kinetic model 总被引:1,自引:0,他引:1
Photooxidative decolorization of four textile dyestuffs, C.I. Acid Orange 7 (AO7), C.I. Acid Orange 8 (AO8), C.I. Acid Orange 52 (AO52) and C.I. Acid Blue 74 (AB74), by UV/H2O2 was investigated in a laboratory scale photoreactor equipped with a 15 W low pressure mercury vapour lamp. The decolorization of the dyes was found to follow pseudo-first-order kinetics, and hence the figure-of-merit electrical energy per order (E(Eo)) is appropriate for estimating the electrical energy efficiency. The E(Eo) values were found to depend on the concentration of H2O2, concentration and basic structure of the dye. This study shows that these textile dyes can be treated easily and effectively with the UV/H2O2 process with E(Eo) values between 0.4 and 5 kW h m-3 order-1, depending on the initial concentrations of dyes and H2O2. The kinetic model, based on the initial rates of degradation, provided good prediction of the E(Eo) values for a variety of conditions. 相似文献
463.
van Straalen NM Donker MH Vijver MG van Gestel CA 《Environmental pollution (Barking, Essex : 1987)》2005,136(3):409-417
It is often argued that the concentration of a pollutant inside an organism is a good indicator of its bioavailability, however, we show that the rate of uptake, not the concentration itself, is the superior predictor. In a study on zinc accumulation and toxicity to isopods (Porcellio scaber) the dietary EC(50) for the effect on body growth was rather constant and reproducible, while the internal EC(50) varied depending on the accumulation history of the animals. From the data a critical value for zinc accumulation in P. scaber was estimated as 53 microg/g/wk. We review toxicokinetic models applicable to time-series measurements of concentrations in invertebrates. The initial slope of the uptake curve is proposed as an indicator of bioavailability. To apply the dynamic concept of bioavailability in risk assessment, a set of representative organisms should be chosen and standardized protocols developed for exposure assays by which suspect soils can be evaluated. 相似文献
464.
Spinelli LF Schnaid F Selbach PA Bento FM Oliveira JR 《Journal of the Air & Waste Management Association (1995)》2005,55(4):421-429
This paper presents a study of the bioremediation of diesel oil and gasoline by a series of controlled laboratory tests. Sludge from an agroindustry was used to enhance bioremediation of both gasoline and diesel oil mixed with a soil mass to compare its efficiency with that of a mineral fertilizer. Effects of soil microbiology and soil mixtures were investigated by means of evolution of CO2, microorganism populations at 90 days, pH at 65 and 95 days, mineral nitrogen, and gas chromatographic analysis of the benzene, toluene, methyl tertiary butyl ether, C8, and C9+total aromatics at the end of the experiments. Treatments containing sludge showed better soil conditions after 170 days of treatment (inorganic nitrogen and microbiota activity) compared with gasoline and diesel oil without amendments. Samples had no detectable traces of the measured hydrocarbons at 170 days of treatment. 相似文献
465.
Monitoring and toxicity of sulfonated derivatives of benzene and naphthalene in municipal sewage treatment plants 总被引:1,自引:0,他引:1
Alonso MC Tirapu L Ginebreda A Barceló D 《Environmental pollution (Barking, Essex : 1987)》2005,137(2):253-262
Monitoring benzenesulfonates (BS) and naphthalenesulfonates (NS) took place in five municipal sewage treatment plants (STP). A previously optimized method based on solid phase extraction with polymeric cartridges followed by ion-pair liquid chromatography-electrospray-mass spectrometry (SPE-IPC-ESI-MS) was used. This work confirmed the little or no effect of primary settlement on total organic carbon (TOC) and monosulfonated compounds removal, whereas the main reduction is obtained at the biological stage. However, the most polar compounds, such as naphthalenedisulfonates (NDS), were not effectively removed using the biological treatment. An aromatic sulfonated compound is suggested to be used as a tracer of the origin of industrial pollutants discharged into STPs. A bioluminescence inhibition test, Microtox assay, allowed toxicity determination of the most relevant aromatic sulfonated compounds detected and toxicity comparison between primary and secondary effluents. 相似文献
466.
Temporal variation of trace metal geochemistry in floodplain lake sediment subject to dynamic hydrological conditions 总被引:1,自引:0,他引:1
van Griethuysen C Luitwieler M Joziasse J Koelmans AA 《Environmental pollution (Barking, Essex : 1987)》2005,137(2):281-294
Climate change and land use may significantly influence metal cycling in dynamic river systems. We studied temporal variation of sediment characteristics in a floodplain lake, including concentrations of dissolved organic carbon, acid volatile sulfide and trace metals. The sampling period included a severe winter inundation and a dramatic water level drop during summer. Temporal changes were interpreted using multivariate analysis and chemical equilibrium calculations. Metal concentrations in sediment increased with depth, indicating a gradual improvement of sediment quality. In contrast, dissolved metal concentrations were highest in top layers due to mobilization from oxyhydroxides and precipitation with sulfides in deeper layers. Inundation had a mobilizing effect as it stimulated resuspension and oxygenation of sediment top layers. Water table lowering combined with organic matter decomposition led to immobilization due to sulfide formation. The chemistry of the sediments was consistent with model calculations, especially for macro-elements. The results illustrate the importance of seasonality for metal risk assessment. 相似文献
467.
Ambrose RB Tsiros IX Wool TA 《Journal of the Air & Waste Management Association (1995)》2005,55(5):547-558
This paper presents a modeling analysis of airborne mercury (Hg) deposited on the Ochlockonee River watershed located in Georgia. Atmospheric deposition monitoring and source attribution data were used along with simulation models to calculate Hg buildup in the subwatershed soils, its subsequent runoff loading and delivery through the tributaries, and its ultimate fate in the mainstem river. The terrestrial model calculated annual watershed yields for total Hg ranging from 0.7 to 1.1 microg/m2. Results suggest that approximately two-thirds of the atmospherically deposited Hg to the watershed is returned to the atmosphere, 10% is delivered to the river, and the rest is retained in the watershed. A check of the aquatic model results against survey data showed a reasonable agreement. Comparing observed and simulated total and methylmercury concentrations gave root mean square error values of 0.26 and 0.10 ng/L, respectively, in the water column, and 5.9 and 1 ng/g, respectively, in the upper sediment layer. Sensitivity analysis results imply that mercury in the Ochlockonee River is dominated by watershed runoff inputs and not by direct atmospheric deposition, and that methylmercury concentrations in the river are determined mainly by net methylation rates in the watershed, presumably in wetted soils and in the wetlands feeding the river. 相似文献
468.
Blubber from bottle-nose dolphins, spinner dolphins, humpback dolphin (Tursiops truncatus, Stenella longirostris and Sousa chinensis) were collected from the Bay of Bengal (southeast coast of India) and analyzed for the organochlorine pesticides hexachlorocyclohexane (HCHs), p,p'-dichlorodiphenyl trichloroethane (DDTs), and polychlorinated biphenyls (PCBs). All nine specimens analyzed contained considerable levels of all the three chemical classes where DDT was in the range of 3330-23330 ng/g; HCHs in the range of 95-765 ng/g; and PCBs in the range of 210-1220 ng/g (wet weight basis). The reasons for this and the variations in the isomer pattern of HCHs and DDT and its metabolites in marine mammal tissues are discussed. 相似文献
469.
The degradation of p-Coumaric acid present in olive oil mill wastewater was investigated as a pretreatment stage to obtain more easily biodegradable molecules, with lower toxicity that facilitates subsequent anaerobic digestion. Thus, photo-Fenton-assisted ozonation has been studied and compared with ozonation at alkaline pH and conventional single ultraviolet (UV) and acid ozonation treatments. In the combined process, the overall kinetic rate constant was split into various components: direct oxidation by UV light, direct oxidation by ozone and oxidation by hydroxyl radicals. Molecular and/or radical ozone reaction was studied by conducting the reaction in the presence and absence of tert-butylalcohol at pHs 2, 7 and 9. Ozone oxidation rate increases with pH or by the addition of Fenton reagent and/or UV radiation due to generation of hydroxyl radicals, *OH. Hydrogen peroxide and ferrous ion play a double role during oxidation since at low concentrations they act as initiators of hydroxyl radicals but at high concentrations they act as radical scavengers. Finally, the additional levels of degradation by formation of hydroxyl radicals have been quantified in comparison to the conventional single processes and an equation is proposed for the reaction rate as a function of studied operating variables. 相似文献
470.
Although quarrying is often cited as a potential threat to wetland systems, there is a lack of relevant, quantitative case studies in the literature. The impact of pumped groundwater discharged from a quarry into a wetland area was assessed relative to reference conditions in an adjacent fen wetland that receives only natural runoff. Analysis of vegetation patterns at the quarry wetland site, using Detrended Correspondence Analysis and the species indicator values of Ellenberg, revealed a clear disparity between community transitions in the quarry wetland and the reference site. Limited establishment of moisture-sensitive taxa, the preferential proliferation of robust wetland species and an overall shift towards lower species diversity in the quarry wetland were explicable primarily by the physico-chemical environment created by quarry dewatering. This encompassed high pH (up to 12.8), sediment-rich effluent creating a nutrient-poor substrate with poor moisture retention in the quarry wetland, and large fluctuations in water levels. 相似文献