Journal of Material Cycles and Waste Management - Globally, there is rising awareness of the severity of the plastic waste problem, and the implications of plastics accumulation in the environment.... 相似文献
Journal of Material Cycles and Waste Management - The recovery of Pd from spent catalysts has been gaining attention due to its high economic value and limited availability in nature. To recover... 相似文献
Environmental epidemiology and health risk and impact assessment have long grappled with problems of uncertainty in data and
their relationships. These uncertainties have become more challenging because of the complex, systemic nature of many of the
risks. A clear framework defining and quantifying uncertainty is needed. Three dimensions characterise uncertainty: its nature,
its location and its level. In terms of its nature, uncertainty can be both intrinsic and extrinsic. The former reflects the
effects of complexity, sparseness and nonlinearity; the latter arises through inadequacies in available observational data,
measurement methods, sampling regimes and models. Uncertainty occurs in three locations: conceptualising the problem, analysis
and communicating the results. Most attention has been devoted to characterising and quantifying the analysis—a wide range
of statistical methods has been developed to estimate analytical uncertainties and model their propagation through the analysis.
In complex systemic risks, larger uncertainties may be associated with conceptualisation of the problem and communication
of the analytical results, both of which depend on the perspective and viewpoint of the observer. These imply using more participatory
approaches to investigation, and more qualitative measures of uncertainty, not only to define uncertainty more inclusively
and completely, but also to help those involved better understand the nature of the uncertainties and their practical implications. 相似文献
To aid air quality model development and assess air quality forecasts, the Meteorological Development Laboratory (MDL) provided
categorical verification metrics for developmental aerosol predictions. The National Air Quality Forecasting Capability (NAQFC)
generated 48 h (of) gridded hourly developmental predictions for the lower 48 states (CONUS) domain in 12 km horizontal spacing.
The NAQFC uses the North American Mesoscale (NAM) model with EPA’s Community Multiscale Air Quality (CMAQ) model to produce
predictions of ground level aerosol concentrations. We used bilinear interpolation to calculate predicted daily maximum values
at the location of the observation sites. We compared these interpolated predicted values to the observed daily maximum to
produce 2 × 2 contingency tables, with a threshold of 40 μg/m3 during the months of March–August, 2007. The model showed some degree of skill in predicting aerosol exceedances. These results
are preliminary as the NAQFC model for aerosol prediction is in the developmental stage. A more comprehensive performance
evaluation will be accomplished in 2008, when more data become available. Our verification metrics included categorical analyses
for Fraction Correct (FC) or percent correct (FC × 100), Threat Score (TS) or Critical Success Index (CSI), Probability of
Detection (POD), and the False Alarm Rate (FAR), Mean Absolute Error (MAE) and mean algebraic error or bias, where bias is
forecast minus observation. Graphic products included weekly statistics for the CONUS displayed in the form of bar charts,
scatterplots, and graphs. In addition, we split the CONUS into six geographic regions and provided regional statistics on
a monthly basis. MDL produced spatial maps of daily 1-h maximum predicted aerosol values overlaid with the corresponding point
observations. MDL also provided spatial maps of the daily maximum of the 24-h running average. We derived the 24-h running
average from the 1-h average predicted aerosol values and observations. 相似文献
Wind-tunnel simulations were employed to evaluate the wind environment around a tested residential area located near industrial
complexes. The scaled-down geomorphological model of the test area was placed in the test section of a boundary layer wind
tunnel. Particle image velocimetry (PIV) measurements were made in five vertical planes and one horizontal plane around the
test area for two prevailing wind directions. The results showed that the wind speed decreased in the near surface layer and
the velocity fluctuations increased in the upper region due to the presence of hills and high-rise buildings around the test
area. Regions of flow separation and low-speed flow were found inside the test area for both the wind directions. The result
suggests that the high-rise buildings should be well arranged with respect to the main wind directions to increase the natural
ventilation inside the residential complex at the initial design stage. 相似文献
• Submerged arc plasma was introduced in terms of wastewater treatment.• Ozone oxidation was coupled with submerged arc plasma system.• Ozone was converted into O and O2 by submerged arc plasma.• Decomposition rate was accelerated by submerged arc plasma.• Introduction of ozone led to significant increase in mineralization. Submerged arc plasma technology was assessed for the removal of phenols from wastewater. The OH radicals generated from the boundary between the plasma and waste solution were considered as a significant factor on the degradation reaction. In this study, the effects of highly energetic electrons released from the submerged arc plasma were mainly studied. The highly energetic electrons directly broke the strong chemical bond and locally increased the reaction temperatures in solution. The effects of the submerged-arc plasma on the decomposition of phenol are discussed in terms of the input energy and initial concentration. The single use of submerged arc plasma easily decomposed the phenol but did not increase the mineralization efficiency. Therefore, the submerged arc plasma, coupled with the ozone injection, was investigated. The submerged arc plasma combined with ozone injection had a synergic effect, which led to significant improvements in mineralization with only a small increase in input energy. The decomposition mechanism of phenol by the submerged arc plasma with the ozone was analyzed. 相似文献
Environmental Geochemistry and Health - In this study, soil washing is applied for the remediation of heavy-metal (Pb, Cu and Zn) contaminated paddy soil located near an abandoned mine area. FeCl3... 相似文献
Biochar derived from food waste was modified with Fe to enhance its adsorption capacity for As(III), which is the most toxic form of As. The synthesis of Fe-impregnated food waste biochar (Fe-FWB) was optimized using response surface methodology (RSM), and the pyrolysis time (1.0, 2.5, and 4.0 h), temperature (300, 450, and 600 °C), and Fe concentration (0.1, 0.3, and 0.5 M) were set as independent variables. The pyrolysis temperature and Fe concentration significantly influenced the As(III) removal, but the effect of pyrolysis time was insignificant. The optimum conditions for the synthesis of Fe-FWB were 1 h and 300 °C with a 0.42-M Fe concentration. Both physical and chemical properties of the optimized Fe-FWB were studied. They were also used for kinetic, equilibrium, thermodynamic, pH, and competing anion studies. Kinetic adsorption experiments demonstrated that the pseudo-second-order model had a superior fit for As(III) adsorption than the pseudo-first-order model. The maximum adsorption capacity derived from the Langmuir model was 119.5 mg/g, which surpassed that of other adsorbents published in the literature. Maximum As(III) adsorption occurred at an elevated pH in the range from 3 to 11 owing to the presence of As(III) as H2AsO3? above a pH of 9.2. A slight reduction in As(III) adsorption was observed in the existence of bicarbonate, hydrogen phosphate, nitrate, and sulfate even at a high concentration of 10 mM. This study demonstrates that aqueous solutions can be treated using Fe-FWB, which is an affordable and readily available resource for As(III) removal.
Environmental Geochemistry and Health - Paddy fields near metalliferous mining area are sometimes contaminated by tailings or mine water. In the contaminated paddy fields around the abandoned... 相似文献
Environmental Science and Pollution Research - A simple oxidation method for preparing CuO nanodisks on a flexible Cu sheet is presented. The crystal structure of as-prepared CuO nanodisks was... 相似文献