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1.
The distribution and accumulation of heavy metals (Al, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Mo, Cd, Sn, Ba, Pb) in the water, sediments, plankton of Yeniça?a Lake, and its potential sources (creeks, sewage, artesian well, soil) were investigated during 1-year study period as monthly or seasonally. Element analyses were performed by ICP–MS. Results showed that the trace and toxic elements (Al, As, Mn, Pb, Fe) concentration in lake water and/or its feeding sources were above the recommended water standards (WHO, EC, EPA, TS-266). It was found that the maximum accumulation of the heavy metals iron, aluminum, manganese, zinc, and barium in the sediment of Yeniça?a Lake. The accumulation order of trace metals were Fe > Al > Mn > Zn > Ba > Ni > Cr > As > Cu > Pb > Co > Mo > Sn > Cd in the lake, creeks sediment, and soil samples. The similar results suggest that the accumulation of heavy metals in the sediment is a natural process. Metals accumulated in the lake are naturally mixed from the soil. However, the presence of heavy metals in the analysis of artesian well water and sewage reveals that the transportation occurs also from the groundwater to the lake. The results obtained in plankton in Yeniça?a Lake showed that aluminum, iron, manganese, zinc, and barium were most accumulated elements in the plankton. The lower averages of lead prevalent in the water and sediment during some months were seen to have a significant mean accumulation in the plankton.  相似文献   

2.
The increased pollution in ecosystems reinforces the importance of both chemical monitoring and biological monitoring of streams and rivers, as an effective water quality-based approach to assess aquatic ecosystem health. In this study, gudgeon (Gobio gobio) and mullet (Mugil cephalus) liver histopathology (biomarker) and some macroinvertebrate community indexes and metrics (bioindicator) were used to evaluate the effect of the wastewater treatment plant (WWTP) of Febros (Avintes) in Febros River water quality and ecosystem health. Regarding macroinvertebrate communities, the Belgian Biotic Index (BBI) and Iberian Biological Monitoring Working Party (IBMWP) indexes suggested that Febros water was slightly polluted, even though the worst situation was found downstream the WWTP discharge. Concerning community metrics, upstream percent of individuals in five numerically dominant taxa (80%) was slightly more superior than the downstream (78%). The presence of intolerant or sensible individuals, determined by percent of Ephemeroptera, Plecoptera, and Trichoptera individuals and number of Ephemeroptera, Plecoptera, and Trichoptera families metrics, was higher upstream WWTP, reflecting a better water quality. The histopathology shows the presence of hepatic lesions in gudgeon and mullet. The statistical analysis of the lesion gradation showed that only necrosis was significantly higher in gudgeon captured downstream the WWTP, while differences were not observed for mullet. The multivariate analysis of data confirmed the existence of differences in hepatic lesions between gudgeon and mullet and between sampling sites. Regarding macroinvertebrate community, this analysis showed that the organic contamination reflected by the BBI and IBMWP indexes values was a determinant factor in the spatial distribution of macroinvertebrates. This work showed that the study of different biological organization levels can be used for a better assessment of ecosystem ecological integrity and can be used as a tool to reveal anthropogenic activity effects in macroinvertebrate diversity and in fish liver pathology from Febros River.  相似文献   

3.
Ashtamudi estuary, situated on the southwest coast of India, is enormously affected by anthropogenic interventions. Physicochemical quality of water and sedimentological features of the estuary are evaluated during monsoon and nonmonsoon seasons to elucidate its quality variations and to link the same with existing environmental scenario. The whole data has been factorized using principal component analysis for extracting the total variability and linear relationships existing among a set of different physicochemical parameters of the backwater system. In PCA, high loadings were obtained for conductivity, salinity, fluoride, calcium, magnesium, sulfate, boron, and pH. The results were revealed that all the physicochemical processes depend upon seasonal fluctuation of freshwater input and seawater intrusion. Wide spatial concentration fluctuations of organic carbon and iron in bottom sediment have been noticed and both constituents reveal good correlation with sediment texture. The results showed high deterioration of the physicochemical quality of water during nonmonsoon season with respect to monsoon season.  相似文献   

4.
Accumulation dynamics and cellular locations of lead (Pb), zinc (Zn) and cadmium (Cd) were studied in Flavocetraria nivalis lichens near the former Black Angel Pb–Zn Mine in West Greenland. Natural resident thalli were collected from four dust-contaminated sites near the mine. In addition, thalli were taken from an uncontaminated reference site and transplanted to the contaminated sites followed by a collection 1 year after. Total thalli metal contents were determined, and thalli were subjected to a sequential extraction procedure. After 1 year of transplantation, total Pb thalli contents were significantly elevated compared with initial concentrations at all sites (for Zn and Cd contents only at the two sites closest to the mine). However, transplanted thalli contained significantly less Pb (26?±?12 %), Zn (64?±?13 %) and Cd (34?±?7 %) compared with resident thalli from these sites. Results from the sequential extraction procedure showed marked differences among Pb, Zn and Cd in the extracellular, intracellular and residual fraction. The lower total metal concentrations in transplanted compared with resident thalli at the contaminated sites were mostly due to a larger metal content bound in the residual fraction in resident thalli. In contrast, the metal content bound in the extracellular fraction were not significantly different in transplanted and resident thalli. The results indicate that extracellular-bound Pb, Zn and Cd in F. nivalis can be used as a proxy for recent (annual) atmospheric metal deposition whereas the large residual metal fraction in resident lichens indicate an accumulation of metal-containing particles in the thalli over time that includes several years of uptake.  相似文献   

5.
This study aimed at quantifying noise pollution from urban traffic in the city of Kahramanmara?, Turkey. A total of 114 measurements for the equivalent noise level (L Aeq) were made at 38 urban locations classified as “residential areas”, “residential and commercial areas” and “industrial areas” according to the national regulations, during morning, mid-day and evening hours. Our findings tabulated and mapped revealed that mean noise level in “residential and commercial areas” was highest relative to the other land-use types. Minimum and maximum values of noise pollution were recorded during the mid-day and evening hours, regardless of the land-use types. Noise limit values were exceeded at two locations only out of 38 based on the national regulation criteria and at over half of the locations based on the international criteria.  相似文献   

6.
A modified Streeter–Phelps equation and the Hydrological Engineering Centers River Analysis System (HEC-RAS) were combined to assess water quality of the Tan-Sui River and its tributaries. The Tan-Sui River is the main source of water supply for northern Taiwan, and the water quality of its stream is significantly affected by tides. In this study, HEC-RAS was employed to assess the impact of tides on water quality and to calculate reoxygenation coefficients. The modified Streeter–Phelps equation was used to calculate water quality in terms of contaminant degradation and reoxygenation. Biochemical oxygen demand (BOD) and ammonia nitrogen (NH3–N), the most important identified sources of water pollution in the rivers investigated, were evaluated. Dissolved oxygen (DO) was also simulated, since it is often used as a staple of water quality. Results showed that employing HEC-RAS for hydraulic calculations improves the modified Streeter–Phelps simulation. In river sections without tidal influence, water quality was sensitive to the BOD and NH3–N degradation constants. Downstream of Chin-Mei Creek, while the BOD degradation constant decreased by 80%, BOD and DO concentrations increased from 7.1?mg/L to 10.7?mg/L and 5.0?mg/L to 7.2?mg/L, respectively, indicating that water quality was not as sensitive to variations of the BOD degradation constant as expected. The concentrations of DO and BOD at the river mouth had a significant impact on water quality for the tidal sections of the investigated rivers due to mixing of tidal and river waters. The BOD and NH3–N degradation constants in the tidal sections had little impact on water quality simulations. This study demonstrated the innovative combination of the modified Streeter–Phelps equation and HEC-RAS to assess the impact of tidal variation and to simulate the water quality of a tidal river when available data is rather limited.  相似文献   

7.
The behaviour of arsenic and antimony in the Ría de Arousa (Galicia, north west of Spain) and the influence of the Prestige accident in the estuary is evaluated. As and Sb were simultaneously determined by HG-ICPOES in seawater samples after a preconcentration with La in a knotted reactor. The highest As concentration is in the inner and middle parts of the ría where the current is weaker and next to the main ports of the area. The largest Sb concentrations were found in the bay of the ría. Linear variation of concentration vs. salinity for As and As/Sb ratios indicated that there was no pollution in the waters of Arousa. The Prestige oil spillage had no serious influence and the values of arsenic (most of them <1.5 microg L(-1)) are similar to the average oceanic concentration, whereas concentrations for antimony (most of them <0.15 microg L(-1)) are less than the oceanic ones.  相似文献   

8.
For the health and safety of the public, it is essential to measure spatiotemporal distribution of air pollution in a region and thus monitor air quality in a fine-grain manner. While most of the sensing-based commercial applications available until today have been using fixed environmental sensors, the use of personal devices such as smartphones, smartwatches, and other wearable devices has not been explored in depth. These kinds of devices have an advantage of being with the user continuously, thus providing an ability to generate accurate and well-distributed spatiotemporal air pollution data. In this paper, we review the studies (especially in the last decade) done by various researchers using different kinds of environmental sensors highlighting related techniques and issues. We also present important studies of measuring impact and emission of air pollution on human beings and also discuss models using which air pollution inhalation can be associated to humans by quantifying personal exposure with the use of human activity detection. The overarching aim of this review is to provide novel and key ideas that have the potential to drive pervasive and individual centric and yet accurate pollution monitoring techniques which can scale up to the future needs.  相似文献   

9.
Concentrations of Ni, Cd, Pb, Cu, and Zn were measured in the surface sediments of Mejillones Bay at 32 sites ranging in depth from 10 to 95 m. A similarity dendrogram analysis separated the study area into two large sedimentary facies: a coastal zone with low metal concentrations and a deep zone with high metal concentrations. The abundances of Zn, Ni, and Pb increased between two sampling periods (5 years apart) in association with greater anthropogenic activity along the coastline of the bay at the present. The results were analyzed with the index of geoaccumulation and by applying the sediment quality guideline. Although similar to preindustrial levels, current Cu and Ni concentrations pose a likely threat to communities of benthic organisms. Concentrations of Zn and Pb are enriched, probably in connection with the industrial development of the zone, but do not reach dangerous levels for the benthic communities. Cd concentrations are toxic to benthic life, even though those measured herein are similar to preindustrial levels. Thus, these Cd levels are a result of the bay's natural characteristics (e.g., high biological productivity, the microxic water-sediment interface). The results of the Chilean aquatic sediment quality standards and the international standard (sediment quality guideline) were similar but differed from those found using the index of geoaccumulation, which suggests that the proposed reference values for Chilean aquatic sediment should be reviewed.  相似文献   

10.
Investments in power generation constitute a typical budget allocation problem in the context of multiple objectives, while all factors influencing investor’s decisions for power plants are subject to considerable uncertainties. The paper introduces a multi-objective stochastic model designed to optimize budget allocation decisions for power generation in the context of risk aversion taking into account several sources of uncertainty, especially with regard to volatility of fossil fuel and electricity prices, technological costs, and climate policy variability. Probability distributions for uncertain factors influencing investment decisions are directly derived from the stochastic global energy model PROMETHEUS and thus they take into account complex interactions between variables in the systemic context. In order to fully incorporate stochastic characteristics of the problem, the model is specified as an optimization problem in which the probability that an objective exceeds a given threshold is maximized (risk aversion) subject to a set of deterministic and probabilistic constraints. The model is formulated as a mixed integer program providing complete flexibility on the joint distributions of rates of return of technologies competing for investments, as it can handle non-symmetric distributions and take automatically into account complex covariance patterns as emerging from comprehensive PROMETHEUS stochastic results. The analysis shows that risk is a crucial factor for power generation investments with investors not opting for technologies subject to uncertainty related to climate policies and fossil fuel prices. On the other hand, combination of options with negative covariance tends to benefit in the context of risk-hedging behavior.  相似文献   

11.
A typical onsite wastewater treatment system consists of a septic tank and a soil treatment unit to treat wastewater before it is discharged through the vadose zone to an aquifer. A tool was developed for the purpose of predicting the fate and transport of nitrogen in soil treatment units (STUMOD or Soil Treatment Unit Model). STUMOD calculates nitrogen species concentrations and the fraction of total nitrogen reaching the aquifer or a specified soil depth. Input data include parameters for hydraulics and nutrient transport and transformation. An analytical solution is used to calculate the profile of pressure based on Darcy’s equation and the relationships between suction head, unsaturated hydraulic conductivity, and soil moisture. Chemical transport is based on simplification of the advection–dispersion equation. STUMOD is relatively simple to use but accounts for important processes such as ammonium sorption, nitrification, and denitrification. STUMOD accounts for the effect of soil moisture content (a surrogate for redox conditions) on nitrification and denitrification reactions. The model has provisions to handle the influence of temperature and organic carbon content on nitrogen transformation. Model outputs, generated based on input parameters obtained from extensive literature review, were compared to a numerical model and data from laboratory tests and field sites. Both measured data and STUMOD outputs show a relatively higher removal in clayey soils compared to sandy soils. Consistent with literature data for most soils, STUMOD predicted ammonium conversion to nitrate within the first foot below the trench infiltrative surface.  相似文献   

12.
While probability sampling has the advantage of permitting unbiased population estimates, many past and existing monitoring schemes do not employ probability sampling. We describe and demonstrate a general procedure for augmenting an existing probability sample with data from nonprobability-based surveys (found data). The procedure, first proposed by Overton (1990), uses sampling frame attributes to group the probability and found samples into similar subsets. Subsequently, this similarity is assumed to reflect the representativeness of the found sample for the matching subpopulation. Two methods of establishing similarity and producing estimates are described: pseudo-random and calibration. The pseudo-random method is used when the found sample can contribute additional information on variables already measured for the probability sample, thus increasing the effective sample size. The calibration method is used when the found sample contributes information that is unique to the found observations. For either approach, the found sample data yield observations that are treated as a probability sample, and population estimates are made according to a probability estimation protocol. To demonstrate these approaches, we applied them to found and probability samples of stream discharge data for the southeastern US.  相似文献   

13.
We propose a stochastic dynamic programming framework to model the management of a multi-stand forest under climate risk (strong wind occurrence). The preferences of the forest-owner are specified by a non-expected utility in order to separately analyze intertemporal substitution and risk aversion effects. A numerical method is developed to characterize the optimal forest management policies and the optimal consumption-saving strategy. The stochastic dynamic programming framework is applied to a non-industrial private forest-owner located in North-East of France. We show that the optimal decisions both depend upon risk and time preferences. The authors would like to thank participants at the international conference on Economics of Sustainable Forest Management in Toronto, at the PARIS 1 seminar on Environmental and Natural Resource Economics, at the 2004 Applied Microeconomics Conference in Lille and at the 13th annual conference of the European Association of Environmental and Resource Economists at Budapest.  相似文献   

14.
In order to optimize the processes of sampling, monitoring, and management, the initial aim of this paper was to develop a model for the definition and prediction of temporal changes of water quality. In the case of the Morava River Basin (Serbia), the patterns of temporal changes have been recognized by applying different multivariate statistical techniques. The results of the conducted cluster analysis are the indicators of the existence of the three monitoring periods: the low-water, transitional, and high-water periods, which is in accordance with changes in the water flow in the analyzed river basin. A possibility of reducing the initial data set and recognizing the main pollution sources was examined by carrying out the principal component/factor analysis. The results indicate that the natural factor has a dominant influence in temporal groups. In order to recognize the discriminatory water quality parameters, a discriminant analysis (DA) was carried out. Conducting the DA enabled a significant reduction in the data set by the extraction of two parameters (the water temperature and electrical conductivity). Furthermore, the artificial neural network technique was used for testing the possibility of predicting changes in the values of the discriminant factors in the monitoring periods. The reliability of this method for the prediction of temporal variations of both extracted parameters within all temporal clusters has been proven.  相似文献   

15.
Government and environmental entities are becoming increasingly concerned with qualifying and quantifying the erosion effects that are observed in sandy shores. Correspondingly, survey methodologies that gather data for such erosion studies are increasingly being demanded. The responsible entities are continually broadening their areas of interest, are concerned in the establishment of regular monitoring programmes and are demanding high accuracy from the geo-spatial data that is collected. The budget available for such monitoring activities, however, does not parallel the trend in the increasing demand for quality specifications. Survey methodologies need improvement to meet these requirements. We have developed a new land-based survey system--the INSHORE system--that is ideal for low cost, highly efficient and highly precise coastal surveys. The INSHORE system uses hi-tech hardware that is based on high-grade global positioning system (GPS) receivers and a laser distance sensor combined with advanced software algorithms. This system enables the determination of the ground coordinates of the surveyed areas with a precision of 1 to 2 cm, without having a sensor in contact with the ground surface. The absence of physical contact with the ground makes this system suitable for high-efficiency surveys. The accuracy of the positioning, which is based on advanced differential GPS processing, is enhanced by considering the estimated attitude of the GPS receiver holding structure and eliminates undesirable offsets. This paper describes the INSHORE survey system and presents the results of validation tests that were performed in a sandy shore environment.  相似文献   

16.
From February 15th to April 15th 2009, a period characterised by two episodes of Saharan dust outbreaks in Italy, particulate matter (PM) samples were collected at two stations (urban and suburban) in Rome. Some samples were selected and analysed using the SEM-EDS technique to characterise PM, focussing especially on the mineral contribution. Samples were representative both of days affected by Saharan dust episodes and days without this contribution. Cluster analysis allowed the attribution of each of about 67,000 analysed particles to one of the seven main statistical groups based on their composition. Characteristics of the particulate components identified using SEM-EDS analysis were verified by PIXE analysis carried out on filters collected in a suburban area. Ultimately, the contribution of crustal particles was revealed to be consistently high, highlighting the importance of local and regional mineral contributions, as well as those of Saharan origin. Therefore, quantifying all mineral contributions to resuspended particulate could lead to significant reductions of the PM level also on days not influenced by Saharan dust, thus limiting conditions when PM?? daily limit value (DLV) established by European legislation is exceeded.  相似文献   

17.
Coastal and estuarine areas are often polluted by heavy metals that result from industrial production and agricultural activities. In this study, we investigated the concentration trait and vertical pattern of trace elements, such as As, Cd, Ni, Zn, Pb, Cu, and Cr, and the relationship between those trace elements and the soil properties in coastal wetlands using 28 profiles that were surveyed across the Diaokouhe Nature Reserve (DKHNR). The goal of this study is to investigate profile distribution characteristics of heavy metals in different wetland types and their variations with the soil depth to assess heavy metal pollution using pollution indices and to identify the pollution sources using multivariate analysis and sediment quality guidelines. Principal component analysis, cluster analysis, and pollution level indices were applied to evaluate the contamination conditions due to wetland degradation. The findings indicated that the concentration of trace elements decreased with the soil depth, while Cd increases with soil depth. The As concentrations in reed swamps and Suaeda heteroptera surface layers were slightly higher than those in other land use types. All six heavy metals, i.e., Ni, Cu, As, Zn, Cr, and Pb, were strongly associated with PC1 (positive loading) and could reflect the contribution of natural geological sources of metals into the coastal sediments. PC2 is highly associated with Cd and could represent anthropogenic sources of metal pollution. Most of the heavy metals exhibited significant positive correlations with total concentrations; however, no significant correlations were observed between them and the soil salt and soil organic carbon. Soil organic carbon exhibited a positive linear relationship with Cu, Pb, and Zn in the first soil layer (0–20 cm); As, Cr, Cu, Ni, Pb, and Zn in the second layer (20–40 cm); and As, Cr, Cu, Ni, Pb, and Zn in the third layer (40–60 cm). Soil organic carbon exhibited only a negative correlation with Cd (P?I geo values), which averaged less than 0 in the three soil layers, this finding indicates that the soils have remained unpolluted by these heavy metals. The mean concentrations of these trace elements were lower than Class I criteria. The degradation wetland restoration suggestions have also been provided in such a way as to restore the reserved flow path of the Yellow River. The results that are associated with trace element contamination would be helpful in providing scientific directions to restore wetlands across the world.  相似文献   

18.
Data management is becoming increasingly simple and complex at the same time. The challenge is to effectively use the increasing number of tools available to manage increasing amounts of environmental information for purposes of data capture, analysis, display, sharing and storage. Government is no longer the main collector and provider of data. Community groups possess vast amounts of data collected through daily work of monitoring the environment in their local community. The chief concerns are data access, sharing, integrity and comparability. The capacity of groups to sustain data management is the key to making the sharing possible. The Southeast Environmental Association has been working with Environment Canada to develop a community, on-line database that will be linked to other geo-spatial data sets to allow instant access to geo-referenced data.  相似文献   

19.
This paper elucidates the basic approach of determining the path coefficients and its significance in the road traffic noise annoyance. Path model not only outline the direct effect of the traffic noise on the nearby residents but also indicate the indirect effect via other variables. In this study seven variables were considered for determining road traffic noise annoyance. However the same would be equally applicable for other situations like aircraft noise, rail noise, and industry noise with the different variables. At the outset a priori path model was designed and then on the basis of the partial regression coefficient values for the different paths, the revised path model was developed. The standardized partial regression coefficients known as path coefficients, determine the strength of the linkage among variables. Some of the paths in the model were not statistically significant. Revised path models were developed by deleting the insignificant paths whose values were found above 5% level. In the revised path model, thus the direct and indirect effect due to a particular variable causing the road traffic noise annoyance could be observed.  相似文献   

20.
Temporal variations of the ambient mixing ratio of greenhouse gas (CH(4) and N(2)O) in a riparian rice-based agro-ecosystem of tropical region were studied during 2005-2006 in coastal Odisha. The endeavour was made with the hypothesis that the ambient mixing ratio of CH(4) and N(2)O depends on the changes in the flux of CH(4) and N(2)O from the rice fields in the riparian rice ecosystems. A higher ambient mixing ratio of CH(4) was recorded during the tillering to grain filling stages of the rice crop, during both dry and wet seasons. The higher ambient mixing ratio of CH(4) during the wet season may attribute to the higher CH(4) emission from the rice field. The average mixing ratio of CH(4) was recorded as 1.84 ± 0.05 ppmv and 1.85 ± 0.06 ppmv during 2005 and 2006, respectively. The ambient CH(4) mixing ratio was recorded negatively correlated with the average ambient temperature. The N(2)O mixing ratio ranged from 261.57 to 399.44 ppbv with an average of 330.57 ppbv during 2005. However, the average mixing ratio of N(2)O was recorded as 318.83 ± 20.00 ppbv during 2006. The N(2)O mixing ratio was recorded to be negatively correlated with rainfall and average ambient temperature. Significant negative correlation (r = -0.209) of N(2)O with sunshine hours may attribute to the photochemical break down of N(2)O. The temporal variation of N(2)O flux from the rice field does not affect the ambient mixing ratio of N(2)O in the same way as in the case of the ambient mixing ratio of CH(4). However, the higher mixing ratio of N(2)O during the fallow period of the post monsoon period may attribute to the N(2)O flux from soil. Results indicate that intensively cultivated coastal ecosystems can be a major source of ambient greenhouse gas.  相似文献   

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