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991.
Meghann E. Jarchow Justin W. Rice Rebekah M. Ritson Sarah K. Hargreaves 《Sustainability Science》2011,6(2):253-254
Conference organizers are increasingly making efforts to reduce resource use at conferences, yet few responsibilities are
placed on attendees. We hosted an ecology conference and offered attendees a discount if they took a sustainability pledge
agreeing to reduce their resource use at the conference. In a post-conference survey, 83% of respondents reported fulfilling
the pledge, but 62% indicated that convenience was the biggest obstacle impeding their ability to continue the pledge during
and after the conference. We found great willingness by attendees to reduce resource use at and beyond our conference, and
facilitating their participation was an important part of our success. 相似文献
992.
The influence of mariculture on mercury distribution in sediments and fish around Hong Kong and adjacent mainland China waters 总被引:1,自引:0,他引:1
To study the influence of mariculture on mercury (Hg) speciation and distribution in sediments and cultured fish around Hong Kong and adjacent mainland China waters, sediment samples were collected from six mariculture sites and the corresponding reference sites, 200-300 m away from the mariculture sites. Mariculture activities increased total mercury, organic matter, carbon, nitrogen and sulfur concentrations in the surface sediments underneath mariculture sites, possibly due to the accumulation of unconsumed fish feed and fish excretion. However, methylmercury (MeHg) concentrations and the ratio of MeHg to THg (% MeHg) in sediments underneath mariculture sites were lower than the corresponding reference sites. The % MeHg in sediments was negatively correlated (r = −0.579, p < 0.05) with organic matter (OM) content among all sites, indicating that OM may have inhibited Hg methylation in surface sediments. Three mariculture fish species were collected from each mariculture site, including red snapper (Lutjanus campechanus), orange-spotted grouper (Epinephelus coioides) and snubnose pompano (Trachinotus blochii). The average MeHg concentration in fish muscle was 75 μg kg−1 (wet weight), and the dietary intake of MeHg through fish consumption for Hong Kong residents was 0.37 μg kg−1 week−1, which was lower than the corresponding WHO limits (500 μg kg−1 and 1.6 μg kg−1 week−1). 相似文献
993.
Wölz J Grosshans K Streck G Schulze T Rastall A Erdinger L Brack W Fleig M Kühlers D Braunbeck T Hollert H 《Chemosphere》2011,85(5):717-723
Bankside groundwater is widely used as drinking water resource and, therefore, contamination has to be avoided. In the European Union groundwater protection is explicit subject to Water Framework Directive. While groundwater pollution may originate from different sources, this study investigated on impacts via flood events.Groundwater was sampled with increasing distance to the river Rhine near Karlsruhe, Germany. Samples were HPLC-MS-MS analyzed for the river contaminant carbamazepine to indicate river water infiltration, giving permanent presence in 250 m distance to the river (14-47 μg L−1). Following a flood event, concentrations of about 16-20 μg L−1 could also be detected in a distance of 750 m to the river. Furthermore, estrogenic activity as determined with the Yeast Estrogen Screen assay was determined to increase up to a 17β-ethinylestradiol equivalent concentration (E-EQ) = 2.9 ng L−1 near the river, while activity was initially measured following the flood with up to E-EQ = 2.6 ng L−1 in 750 m distance. Detections were delayed with increasing distance to the river indicating river water expansion into the aquifer.Flood suspended matter and floodplain soil were fractionated and analyzed for estrogenic activity in parallel giving up to 1.4 ng g−1 and up to 0.7 ng g−1, respectively. Target analysis focusing on known estrogenic active substances only explained <1% of measured activities.Nevertheless, river water infiltration was shown deep into bankside groundwater, thus, impacting groundwater quality. Therefore, flood events have to be in the focus when aiming for groundwater and drinking water protection as well as for implementation of Water Framework Directive. 相似文献
994.
Partitioning of perfluorooctanoate (PFOA), perfluorooctane sulfonate (PFOS) and perfluorooctane sulfonamide (PFOSA) between water and sediment 总被引:4,自引:0,他引:4
Laboratory partitioning experiments were conducted to elucidate the sorption behaviour and partitioning of perfluoroalkyl compounds (PFCs). Three different sediment types were used and separately spiked with perfluorooctanoate (PFOA), perfluorooctane sulfonate (PFOS) and perfluorooctane sulfonamide (PFOSA) at low environmentally realistic concentrations. PFOA, PFOS and PFOSA were mainly distributed in the dissolved phase at low suspended solid concentrations, indicating their long-range transport potential in the marine environment. In all cases, the equilibrium isotherms were linear and the organic carbon normalised partition coefficients (KOC) decreased in the following order: PFOSA (log KOC = 4.1 ± 0.35 cm3 g−1) > PFOS (3.7 ± 0.56 cm3 g−1) > PFOA (2.4 ± 0.12 cm3 g−1). The level of organic content had a significant influence on the partitioning. For the sediment with negligible organic content the density of the sediment became the most important factor influencing the partitioning. Ultimately, data on the partitioning of PFCs between aqueous media and suspended solids are essential for modelling their transport and environmental fate. 相似文献
995.
To help improve the prediction of bacteria travel distances in aquifers laboratory experiments were conducted to measure the distant dependent sticking efficiencies of two low attaching Escherichia coli strains (UCFL-94 and UCFL-131). The experimental set up consisted of a 25 m long helical column with a diameter of 3.2 cm packed with 99.1% pure-quartz sand saturated with a solution of magnesium sulfate and calcium chloride. Bacteria mass breakthrough at sampling distances ranging from 6 to 25.65 m were observed to quantify bacteria attachment over total transport distances (α(L)) and sticking efficiencies at large intra-column segments (α(i)) (>5m). Fractions of cells retained (F(i)) in a column segment as a function of α(i) were fitted with a power-law distribution from which the minimum sticking efficiency defined as the sticking efficiency of 0.001% bacteria fraction of the total input mass retained that results in a 5 log removal were extrapolated. Low values of α(L) in the order 10(-4) and 10(-3) were obtained for UCFL-94 and UCFL-131 respectively, while α(i)-values ranged between 10(-6) to 10(-3) for UCFL-94 and 10(-5) to 10(-4) for UCFL-131. In addition, both α(L) and α(i) reduced with increasing transport distance, and high coefficients of determination (0.99) were obtained for power-law distributions ofα(i) for the two strains. Minimum sticking efficiencies extrapolated were 10(-7) and 10(-8) for UCFL-94 and UCFL-131, respectively. Fractions of cells exiting the column were 0.19 and 0.87 for UCFL-94 and UCL-131, respectively. We concluded that environmentally realistic sticking efficiency values in the order of 10(-4) and 10(-3) and much lower sticking efficiencies in the order 10(-5) are measurable in the laboratory, Also power-law distributions in sticking efficiencies commonly observed for limited intra-column distances (<2m) are applicable at large transport distances(>6m) in columns packed with quartz grains. High fractions of bacteria populations may possess the so-called minimum sticking efficiency, thus expressing their ability to be transported over distances longer than what might be predicted using measured sticking efficiencies from experiments with both short (<1m) and long columns (>25 m). Also variable values of sticking efficiencies within and among the strains show heterogeneities possibly due to variations in cell surface characteristics of the strains. The low sticking efficiency values measured express the importance of the long columns used in the experiments and the lower values of extrapolated minimum sticking efficiencies makes the method a valuable tool in delineating protection areas in real-world scenarios. 相似文献
996.
Fate of nitrogen for subsurface drip dispersal of effluent from small wastewater systems 总被引:1,自引:0,他引:1
Subsurface drip irrigation systems apply effluent from onsite wastewater systems in a more uniform manner at a lower rate than has been possible with other effluent dispersal methods. The effluent is dispersed in a biologically active part of the soil profile for optimal treatment and where the water and nutrients can be utilized by landscape plants. Container tests were performed to determine the fate of water and nitrogen compounds applied to packed loamy sand, sandy loam, and silt loam soils. Nitrogen removal rates measured in the container tests ranged from 63 to 95% despite relatively low levels of available carbon. A Hydrus 2D vadose zone model with nitrification and denitrification rate coefficients calculated as a function of soil moisture content fit the container test results reasonably well. Model results were sensitive to the denitrification rate moisture content function. Two-phase transport parameters were needed to model the preferential flow conditions in the finer soils. Applying the model to generic soil types, the greatest nitrogen losses (30 to 70%) were predicted for medium to fine texture soils and soils with restrictive layers or capillary breaks. The slow transport with subsurface drip irrigation enhanced total nitrogen losses and plant nitrogen uptake opportunity. 相似文献
997.
Floodplain soils containing elevated levels of polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs) were collected from several locations along the Tittabawassee River (Michigan, USA). The PCDD/F profiles of these soils exhibited distinct congener patterns consistent with byproducts from either chloralkali manufacturing or chlorophenols productions. Black carbon (BC) particles were isolated for the first time from floodplain soil impacted by PCDD/Fs. Petrographic analysis showed that BC particles, including coal, oxidized coal, metallurgical coke, depositional carbon, coal tar/pitch, cenosphere, and charcoal, comprised approximately 30% by volume of the organic fraction with size range of 250 μm-2000 μm from a typical floodplain soil. The BC particles with anthropogenic origin such as pitch and coke associated with the chloralkali production process served as both the source and subsequent transporter for the highly hydrophobic PCDD/Fs. These anthropogenic BC particles were enriched with high levels of PCDFs, containing approximately 1000-fold the concentration found in the bulk soil. The strong association of PCDD/Fs with anthropogenic BC directly impacts the physicochemical and biological availability thus the risk associated with these hydrophobic organochlorines in soils and sediments. 相似文献
998.
van der Ploeg MJ Baveco JM van der Hout A Bakker R Rietjens IM van den Brink NW 《Environmental pollution (Barking, Essex : 1987)》2011,159(1):198-203
Effects of C60 nanoparticles (nominal concentrations 0, 15.4 and 154 mg/kg soil) on mortality, growth and reproduction of Lumbricus rubellus earthworms were assessed. C60 exposure had a significant effect on cocoon production, juvenile growth rate and mortality. These endpoints were used to model effects on the population level. This demonstrated reduced population growth rate with increasing C60 concentrations. Furthermore, a shift in stage structure was shown for C60 exposed populations, i.e. a larger proportion of juveniles. This result implies that the lower juvenile growth rate due to exposure to C60 resulted in a larger proportion of juveniles, despite increased mortality among juveniles. Overall, this study indicates that C60 exposure may seriously affect earthworm populations. Furthermore, it was demonstrated that juveniles were more sensitive to C60 exposure than adults. 相似文献
999.
Plant communities in relation to flooding and soil contamination in a lowland Rhine River floodplain
Schipper AM Lotterman K Leuven RS Ragas AM de Kroon H Hendriks AJ 《Environmental pollution (Barking, Essex : 1987)》2011,159(1):182-189
Using canonical correspondence analysis (CCA), relationships were investigated between plant species composition and flooding characteristics, heavy metal contamination and soil properties in a lowland floodplain of the Rhine River. Floodplain elevation and yearly average flooding duration turned out to be more important for explaining variation in plant species composition than soil heavy metal contamination. Nevertheless, plant species richness and diversity showed a significant decrease with the level of contamination. As single heavy metal concentrations seemed mostly too low for causing phytotoxic effects in plants, this trend is possibly explained by additive effects of multiple contaminants or by the concomitant influences of contamination and non-chemical stressors like flooding. These results suggest that impacts of soil contamination on plants in floodplains could be larger than expected from mere soil concentrations. In general, these findings emphasize the relevance of analyzing effects of toxic substances in concert with the effects of other relevant stressors. 相似文献
1000.
Kros J Frumau KF Hensen A de Vries W 《Environmental pollution (Barking, Essex : 1987)》2011,159(11):3171-3182
The integrated modelling system INITIATOR was applied to a landscape in the northern part of the Netherlands to assess current nitrogen fluxes to air and water and the impact of various agricultural measures on these fluxes, using spatially explicit input data on animal numbers, land use, agricultural management, meteorology and soil. Average model results on NH3 deposition and N concentrations in surface water appear to be comparable to observations, but the deviation can be large at local scale, despite the use of high resolution data. Evaluated measures include: air scrubbers reducing NH3 emissions from poultry and pig housing systems, low protein feeding, reduced fertilizer amounts and low-emission stables for cattle. Low protein feeding and restrictive fertilizer application had the largest effect on both N inputs and N losses, resulting in N deposition reductions on Natura 2000 sites of 10% and 12%, respectively. 相似文献