首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
Heavy metal pollution of soils along North Shuna-Aqaba Highway, Jordan   总被引:1,自引:0,他引:1  
Attention to heavy metal contamination associated with highways or motorways has risen in the last decades because of the associated health hazards and risks. The present study analysed the metal content in soil samples of one of the main highways along the western part of the Jordanian border, the North Shuna–Dead Sea–Aqaba Highway. The metals analysed were Pb, Zn, Cd, Co and Ni. In the samples collected, the recorded average concentrations were as follows: 40 ppm for Ni, 5 ppm for Cd, 79 ppm for Zn, 79 ppm for Pb, and 25 ppm for Co. The average concentrations of Cd, Pb, and Co are higher than the average natural background values of heavy metals. The geo-accumulation index of these metals in the soils under study indicated that they are uncontaminated with Ni, Zn, and Co and moderately contaminated with Cd and Pb. In all of the investigated locations, the study found that concentrations decreased with depth. The cluster statistical analyses and pollution load index were used to relate pollution to land use or highway conditions. Two main trends were identified: (i) higher concentrations were located near intersections close to the urban areas in the Jordan Valley, in association with junctions controlled by traffic lights and check points; and (ii) lower concentrations were found to the southwest in areas of mainly barren landscape close to the Dead Sea and Aqaba.  相似文献   

2.
Landfill leachate samples were collected anaerobically at six locations at the El-Akader landfill site in North Jordan. The collected leachate samples were separated into size fractions with special attention to the distribution of colloids and associated heavy metals. The fraction sizes were 1.2 μm. The maximum concentrations of heavy metals in the analysed leachate samples were Cd 0.6 μg/l, Ni 25 μg/l, Zn 245 μg/l, Cu 15 μg/l and Pb 2.50 μg/l. In the dissolved particular matter the heavy metals concentration ranges were Cd 0.1–1.1 μg/l, Ni 0.35–1.5 μg/l, Zn 85–105 μg/l, Cu 0–0.95 μg/l and Pb 0.5–2.5 μg/l.  相似文献   

3.
Atmospheric total suspended particulate concentrations and metallic element concentrations were measured at three locations, characteristic of urban, suburban and rural sites. The sampling period was from July 2000 to August 2000. The results indicated that the urban sampling site had the highest total suspended particulate concentrations (average 108.61μ1m3), followed by the suburban site (average 60.11μ1m3) and the rural site (average 53.31μ1m3). The average PM2.5 concentrations (24.11μ1m3) were higher than the PM2.5-10 concentrations (12.81μ1m3) at the urban site. The average distributed ratios for PM2.5/PM2.5-10 were about 1.29, 1.53, 0.12, 1.12 and 2.31 for Pb, Zn, Fe, Ni and Cr, respectively. The average total suspended particulate mass ratios for daytime and nighttime were about 1.72. As for the elements Cu, Pb, Zn, Fe, Ni and Cr, these ratios were about 0.63, 0.97, 0.54, 1.66, 0.53 and 1.12, respectively. The total suspended particulate daytime concentrations of Pb and Zn were positively correlated (R = 0.925) at the urban sampling site. The elements Ni and Cr were positively correlated both during the daytime (R = 0.648) and the nighttime (R = 0.511), revealing that they came from the same emission source during daytime and nighttime, at the urban sampling site.  相似文献   

4.
Gallipoli is a small town on the European side of the Dardanelles Strait, in Turkey. More than 450,000 soldiers gave their lives on the Gallipoli Peninsula (Gallipoli Campaign) over a nine-month period during World War I. In that war, many naval and landing bombs were exploded. The ingredients of these bombs may cause heavy metal contamination in soils. An environmental geochemical investigation has been carried out around Gallipoli Peninsula in order to determine the extent of chemical pollution in the soil. The preliminary data reveal that soils in the area are, in general, not contaminated. The concentrations of many heavy metals, such as arsenic (As), cadmium (Cd), copper (Cu), chromium (Cr), cobalt (Co), manganese (Mn), nickel (Ni), lead (Pb), strontium (Sr), vanadium (V) and zinc (Zn) are in the range of those of average agricultural soils. These low concentrations are explained by the good leaching characteristics of Oligocene–Miocene rocks, Pleistocene terrace material, alluvium sandy-silty soils, and surface run-off.  相似文献   

5.
The first heavy metal deposition survey using biological indicators in the forest belt of Ghana was carried out in the year 2002–2003. The selected sampling areas included two mining centres, industrial areas and farming communities. Levels of ten chemical elements namely, Al, As, Cr, Fe, Hg, Mn, Sb, Th, Ti and V present in the lichens at high concentrations that are suspected to be resulting from anthropogenic activities were reported in these areas. The result shows that, the farming communities are relatively clean with the gold mining areas being the most polluted areas with respect to As, Sb and Cr. The industrial areas were found to be relatively polluted with Al, Fe and Ti.  相似文献   

6.
This study reports total levels of chromium, cadmium, nickel and lead in the agricultural land adjacent a factory producing chromate compounds in Kazanli-Mersin. Surface soil samples were collected from fields around the factory as well as from fields farther away to measure contamination due to aerial transportation and deposition of dust produced in the industrial process. Heavy metals in soil were extracted using wet digestion, and concentrations were measured by atomic absorption spectrophotometry. The concentrations were compared with Turkish maximum allowable concentration values. The metal concentrations averaged 80, 0.14, 228 and 431mg1kg-1 for chromium, cadmium, nickel and lead, respectively. Soil samples contaminated with chromium were mainly found 500–20001m from the factory and decreased with increasing distance from the factory. Elevated chromium and nickel concentrations were determined in the soils around the factory, especially to the northwest (prevailing wind) and west. Lead concentrations exceeded the limit in only roadside soils (4000 and 50001m to the west), but tended to increase in the vicinity of industrial activity (especially in the west, the northwest and the north). The cadmium concentration did not exceed the limit and was within the normal range for soils.  相似文献   

7.
This paper aims to evaluate the impact of a polluted site on property values by using the hedonic price method. The case study concerns a lead foundry in a previously industrialised area in northern France. The results are fairly convincing. The impact is confirmed, but appears to be especially apparent at relatively close distances. More than one mile away, the impact is much weaker. Moreover, a chronological analysis, which includes interaction terms, allows one to demonstrate a significant variability in results, depending upon the years being examined. The results obtained are compared with those derived from US studies. It appears that more than one mile away, the calculated impact values are fairly similar, about 1–2% of the average value of a house. In contrast, bearing in mind the higher average property values in the USA, gradient prices in absolute values are, in general, higher in that country.  相似文献   

8.
9.
Public-private partnership efforts are working towards creating green landscapes from abandoned industrial sites. Fabricated soils, potentially an essential element of such landscapes, are designed to substitute for top-soil on the areas free from ground cover and plant community. The aluminosilicate matrix and humus form the soil micelle – the primary unit of any soil complex. Humus formation is a process based on carbon–nitrogen interaction. Sources of carbon can be materials rich in easily composted products like cellulose and polyphenols (plant leaves) or aged lignin polymers (saw dust from different woody plants). The pathways of carbon–nitrogen complexes are discussed. Properties of the fabricated soil components were examined by bio-tests and plant models.  相似文献   

10.
The total suspended particle (TSP) concentration, dry deposition and wind speed were measured with a PS-1 sampler, a dry deposition plate and a Weather Monitor II (#7440), respectively, at the Experimental Farm of Thunghai University in Taiwan. Taiching Industrial Park, Taichung Cong Road (traffic) and a hospital incinerator are close to the sampling site. The sampling time was from August 2001 to December 2001. The average dry deposition flux, the TSP concentration, dry deposition velocities, average wind speed and maximum wind speed were recorded as 617.7 ± 281.4 mg/day/m2, 117.5 ± 17.6 μg/m3, 5.9 ± 2.2 cm/s, 2.7 ± 1.3 m/s and 7.6 ± 2.3 m/s, respectively, at this sampling site. Good correlation coefficients (R) of the TSP concentration and the dry deposition flux with wind speed were found, with values of 0.46 and 0.50, respectively. The concentrations and dry deposition of the total metallic elements were also obtained. The results indicated that the concentrations of anthropogenic elements (Pb, Mn, Cd, Ni, Cr and Zn) were mostly higher than those obtained in other studies around the world. The average dry deposition fluxes and TSP concentrations for Zn and Pb were 0.45 and 0.42, respectively. The same phenomenon was also observed for Fe and Mg (R = 0.59 and 0.65). The results indicate that these elements were all coming from the same emission sources at the farm sampling site.  相似文献   

11.
Bio-remediation of pendimethalin contaminated soil (500 μg/g) was studied in a bio-slurry phase reactor operated in the sequencing batch mode under anoxic–aerobic–anoxic micro-environment. The effect of augmentation with ETP micro-flora on the process performance of the reactor was also evaluated. The reactor was operated with a total cycle period of 120 hours comprising 3 hours of fill, 114 hours of react and 3 hours of decant phases. The Control reactor (without ETP micro-flora) showed 23% of substrate removal efficiency, which may be attributed to the volatile nature of the substrate. The Reactor operated with native soil micro-flora showed more or less equal degradation compared to the control reactor indicating the toxic and inhibitory nature of the substrate over the slurry micro-flora. The reactor augmented with mixed ETP micro-flora showed enhanced performance with more than 90% of substrate removal efficiency within 72 hours of the cycle period. Due to augmentation, the CFU values in the slurry phase system showed a two-fold increase. Process performance during reactor operation was assessed by monitoring pendimethalin concentration and bio-chemical process parameters viz. pH, dissolved oxygen (DO), colony forming units (CFU) and oxygen consumption rate (OCR), during sequence phase operation.  相似文献   

12.
A survey on the concentration of particulate matter in the urban atmosphere was carried out in the city of Sao Carlos, Brazil. Five sites were selected for data collection one in the city centre (high concentration of people and automotive vehicles), three in industrial areas, and one at the interface with the countryside. The particle size distribution and mass concentration, temperature, humidity and wind velocity were measured at each site. In the city centre, the concentration of the particles smaller than 10 μm (PM10) was also measured. The particle size distribution was obtained with a laser scattering particle counter. The total and PM10 concentrations were obtained with high volume samplers. The tests were performed for 75 consecutive weeks. The results show that the particle concentration is sensitive to seasonal conditions. During autumn and winter, which is the drier and windy period of the year, larger particles were dispersed, leading to higher concentrations, both total and PM10. The relative humidity varied with the schedule of sampling and with the season the autumn and winter weeks were much drier than the other periods. Higher rainfall levels coincided with lower particle concentrations. All these results are statistically significant.  相似文献   

13.
Biotic and abiotic transformations of methyl tertiary butyl ether (MTBE)   总被引:1,自引:0,他引:1  
Background Methyl tertiary butyl ether (MTBE) is a fuel additive which is used all over the world. In recent years it has often been found in groundwater, mainly in the USA, but also in Europe. Although MTBE seems to be a minor toxic, it affects the taste and odour of water at concentrations of < 30 μg/L. Although MTBE is often a recalcitrant compound, it is known that many ethers can be degraded by abiotic means. The aim of this study was to examine biotic and abiotic transformations of MTBE with respect to the particular conditions of a contaminated site (former refinery) in Leuna, Germany. Methods Groundwater samples from wells of a contaminated site were used for aerobic and anaerobic degradation experiments. The abiotic degradation experiment (hydrolysis) was conducted employing an ion-exchange resin and MTBE solutions in distilled water. MTBE, tertiary butyl formate (TBF) and tertiary butyl alcohol (TBA) were measured by a gas chromatograph with flame ionisation detector (FID). Aldehydes and organic acids were respectively analysed by a gas chromatograph with electron capture detector (ECD) and high-performance ion chromatography (HPIC). Results and Discussion Under aerobic conditions, MTBE was degraded in laboratory experiments. Only 4 of a total of 30 anaerobic experiments exhibited degradation, and the process was very slow. In no cases were metabolites detected, but a few degradation products (TBF, TBA and formic acid) were found on the site, possibly due to the lower temperatures in groundwater. The abiotic degradation of MTBE with an ion-exchange resin as a catalyst at pH 3.5 was much faster than hydrolysis in diluted hydrochloric acid (pH 1.0). Conclusion Although the aerobic degradation of MTBE in the environment seems to be possible, the specific conditions responsible are widely unknown. Successful aerobic degradation only seems to take place if there is a lack of other utilisable compounds. However, MTBE is often accompanied by other fuel compounds on contaminated sites and anaerobic conditions prevail. MTBE is often recalcitrant under anaerobic conditions, at least in the presence of other carbon sources. The abiotic hydrolysis of MTBE seems to be of secondary importance (on site), but it might be possible to enhance it with catalysts. Recommendation and Outlook MTBE only seems to be recalcitrant under particular conditions. In some cases, the degradation of MTBE on contaminated sites could be supported by oxygen. Enhanced hydrolysis could also be an alternative. - * The basis of this peer-reviewed paper is a presentation at the 9th FECS Conference on 'Chemistry and Environment', 29 August to 1 September 2004, Bordeaux, France.  相似文献   

14.
The scaling behaviour in acid deposition dynamics of 184 monitoring sites under the National Atmospheric Deposition Program (NADP) is analysed for the 1978–2001 period. The results show that: the distribution of weekly hydrogen deposition (WHD) is consistent with a power law in two different regimes separated by a crossover WHD (CWHD), and both the CWHD and its probability density increase as the power law commensurate with the mean of WHD series; the distribution of pH values shows a series behaviour similar to that of WHD and can be depicted as a log–linear model with the same form of Gutenberg–Richter model of earthquake occurrence; and the successive time-duration (weeks) of both acid and non-acid rain also obeys a power law, with the average duration of acid rain scaling as a positive power law and that of non-acid rain as a negative power law of average WHD. The power laws in the acid deposition dynamics are considered to be indicators of self-organisation of the atmosphere under environmental pollution stress.  相似文献   

15.
The CMB8 model was applied for source apportionment of particulate matter in Bangkok area. The 24 h of ambient data were collected and analysed for elemental composition during December 1996 to January 1997 by high volume air samplers at a station in Bangkok, Thailand. Seven source profiles and the average mass concentrations of 42 ambient data were used to run the chemical mass balance (CMB8) model. The source apportionment by CMB8 gave similar results comparing with factor analysis – multiple regression (FA–MR) model of the same data. The results revealed that major sources of particulate matter in Bangkok were: soil (33%), road dust (33%) and automobile (15%). The minor source contributions were: sea salt (4.34%), refuse incineration and biomass burning (0.84%), steel mill (0.62%) and fuel oil combustion (0.35%). The lack of source profile for biomass or open burning in Bangkok resulted in much lower predicted contribution of this source when compared to that from FA–MR. When apply this CMB8 model with daily ambient data, the result revealed that one fourth of daily CMB8 source apportionment had high value of 2 (>4). These exceedance values of Chi2 also point out that one of the selected sources (biomass burning) may not be the true contributing sources. Presumably, accurate biomass burning source profile is needed to improve the CMB calculation of source contributions for particulate matter in Bangkok metropolitan area.  相似文献   

16.
Atmospheric particulate matter was collected at two sites: an Abies boressi forest in central Greece and in Giesta, a coastal-rural site in the centre of Portugal. The extractable organic material consisted primarily of aliphatic hydrocarbons, acids, alcohols, and ketones, with a predominance of molecular weights >C20, derived from vascular plant waxes. Biomarkers for vegetation sources such as phytosterols, triterpenic compounds and essential oils were also detected. Microbial components (>C20), pyrogenic aromatic hydrocarbons and petroleum residues, including hopanes, steranes and cyclic and branched hydrocarbons, were present in the various aerosol extracts. In the apportionment of the various organic fractions to sources, vegetation waxes dominated, contributing to 50–60% of the solvent-extractable material in the aerosols. Petroleum residues and microbial components comprise 25–30% and 15–25% of the organic matter, respectively.  相似文献   

17.
Water quality in terms of nutrient concentrations, turbidity, suspended solids, and chlorophyll a, was studied during 2000–2001 at a total of 27 beaches in the Kihei and West Maui–Lahaina districts of Maui, Hawaiian Islands. Nitrate concentrations varied widely and averaged as much as 15–20 μM at some beaches. Most turbidities fell in the range 1–10 nephelometric turbidity units. Resuspension of bottom sediments on shallow reef flats appeared to be a cause of some of the highest turbidity. Onshore-offshore transect studies showed that turbidity and concentrations of nitrate and chlorophyll a declined dramatically with distance from the shoreline. The dramatic gradients in water quality within the first 100 m from the shoreline and the fact that some violations of water quality criteria within that zone appear to be the result of natural phenomena, underscore the difficulty of assessing the quality of coastal waters based on traditional parameters.  相似文献   

18.
- DOI: http://dx.doi.org/10.1065/espr2006.01.014 Background, Aims and Scope Triazole-derivatives are potent antifungal agents used as systemic agricultural fungicides and against fungal diseases in humans and domestic animals. They act by inhibiting the cytochrome P-450 conversion of lanosterol to ergosterol, thus resulting in faulty fungal cell wall synthesis. Some data have been published about the teratogenic activity of triazoles on rodent embryos: Hypoplasias, abnormal shape, agenesis of the branchial arches, for example, were reported as typical induced malformations. Unfortunately, no data are available on the embryotoxicity of these compounds in amphibians, despite the increasing concern among the scientific community about the phenomenon of global amphibian population declines. The aim of the present work is to evaluate the embryo-lethal and teratogenic potentials of Triadimefon (FON), a triazolederivative widely used as an antimycotic in agriculture, by the test FETAX (Frog Embryos Teratogenic Assay, Xenopus) with particular attention being paid to the analysis of branchial arch malformations. Methods Xenopus laevis embryos were exposed continuously from stage 9 to increasing concentrations of FON and analyzed at stage 47 for mortality and teratogenicity (group I) to determine the median lethal (LC50) and teratogenic (TC50) concentrations. Another two pools of larvae were exposed to FON for a 2 hour period at early gastrula (Group II) or neurula (Group III) stages to verify which period of development is the most sensitive to FON. The malformations observed were further investigated by histological section and cartilage staining with Alcian blue. Results and Discussion The assay has estimated LC50 and TC50 values of 63.8 μM and 2.73 μM, respectively; the resulting TI (Teratogenic Index = LC50/TC50) value of 23.4 has underlined the very high teratogenic risk associated with this compound. Neurulation was more sensitive to FON exposure than gastrulation, since the TC50 estimated values for group III (neurula exposed) specimens was 7.6 times lower than those of group II (gastrula exposed). Interestingly, for each group analyzed, 100% of malformed embryos showed alterations at branchial arch derived cartilages: Anterior cartilages were reduced, missing, fused or incorrectly positioned while gill cartilages were altered only in the most severely affected specimens. In some cases these malformations were associated with hyperpigmentation. Our results support the hypothesis that FON can interfere with Neural Crest Cell (NCC) migration, since craniofacial components and melanophores are derived from neural crest material. Conclusion In conclusion, our data show Triadimefon to be a potent teratogen able to induce specific craniofacial malformation in Xenopus laevis embryos, probably interfering with the NCC migration into the branchial mesenchyme. These results are also interesting for ecotoxicological reasons as FON, as well as other pesticides, are likely to be present in water systems near agricultural or urban areas which may serve as habitats for developing amphibians and fishes. Recommendation and Outlook Our results are in agreement with the data obtained on in vitro cultured rat embryos suggesting that the FON mechanism of action involves strongly conserved molecules. The choice of Xenopus laevis as the model organism allows us to extend the toxicological and teratological observations to a molecular level, in order to search for novel genes regulated by FON exposure.  相似文献   

19.
A study of the air pollution in the Greek coastal town Volos was performed using the available data of the last ten years. Quantile analysis showed that ozone concentrations during weekends were higher by 5–10% in comparison to those on weekdays, while the inverse was observed for the other pollutants, indicating the occurrence of the so called 'weekend effect'. Analysis of the maximum values of the high ozone period showed even higher differences. The pollutants NO, NO2, CO, and SO2 were lower during weekends compared to weekdays, by about 30%, 20%, 25% and 10% respectively.  相似文献   

20.
In this paper, we show the implementation of a modified version of MM5-CMAQ for carrying out an air quality impact analysis for installing an incinerator in the Basque Country model domain (Spain). The modified CMAQ model (EPA USA, 2004) includes Poly-Chlorinated Dibenzop-Dioxins and Dibenzo-Furans (dioxins and furans). This model represents their congeners as divided between gaseous and aerosol forms that exchange mass based on theoretical coefficients for gas to particle portioning. The emission model EMIMO – developed by UPM – has been adapted to incorporate the three metals and the benzo(a)pyrene according to the EMEP annual emission inventory. In addition, the PCDD/F EMEP emission inventory has been incorporated into the EMIMO model to produce proper 1 hr and 1 km × 1 km emission PCDD/F estimation. The emissions of the projected incinerator are incorporated by using the chimney technical parameters and the limit emission values (worst-case scenario) prescribed in the Directive/2000/76/CE.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号