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1.
典型重金属污染农田能源植物示范种植研究   总被引:8,自引:0,他引:8  
为探索安全经济利用重金属中度-重度污染农田的模式,在浙江某典型重金属复合污染农田开展了能源植物(甜高粱Sweet sorghum、甘蔗Saccharum sinensisRoxb.、香根草Vetiveria和盐肤木Rhus chinensis)种植示范研究.结果表明,经施加0.1%的石灰和0.2%的磷矿粉改良后,土壤p...  相似文献   

2.
Preliminary data are presented from a set of experiments designed to promote the use of pyrolysis-GC/MS in bioremediation. Studies were designed to aid researchers in developing a pyrolysis-GC/MS method and identifying how the method could help characterize bioremediation, particularly in organic soils. Since sample size affects the results of pyrolytic analyses, the first experiment demonstrated how an appropriate sample size might be selected for pyrolysis-GC/MS testing. In order to show how quantitative results can be obtained from pyrolysis-GC/MS, a second experiment determined the 'goodness of fit' for a standard curve relating the chromatographic area under a pyrogram to actual mass units. The third experiment investigated ways in which pyrolysis-GC/MS analyses could improve our understanding of bioremediation in organic soils contaminated with crude oil. Experimental results confirmed that differences in analyte mass affect the extent of pyrolytic cracking. In pyrograms of the test soil, the ratio of toluene to total product showed that for a sample mass between 1.8 and 2.0 mg, variability in the cracking pattern was minimized. Unlike deviations outside this range, small deviations within the range did not appreciably effect the toluene ratio. A standard curve was prepared for pyrolytic analyses by plotting the total chromatographic area of all pyrolysis products versus the mass of organic material pyrolyzed. These data were fit with a straight line having an 'R2' of 0.73. Based on a bench scale bioremediation experiment, preliminary pyrolysis-GC/MS results were used to predict that compounds derived from lignin and carbohydrates would be degraded faster in uncontaminated than contaminated soils. Appreciable degradation of both compounds, however, occurred in contaminated soils. In addition, results suggested that using pyrolysis-GC/MS to quantify the sum of all n-alkanes and the ratio of odd to even chain n-alkanes could help researchers distinguish between the degradation of petroleum and non-petroleum hydrocarbons in contaminated and uncontaminated soils.  相似文献   

3.
Mixtures of polycyclic aromatic hydrocarbons (PAHs) and heavy metals are of major concern in contaminated soil. Biodegradation of PAHs in metal-contaminated soils is complicated because metals are toxic and cannot be degraded by biological processes. This investigation considered the effects of Zn and Cu (50, 100, 500 and 1,000 mg/kg) on 14C-phenanthrene biodegradation in soil over 60-day contact time. The presence of Zn at all concentrations and low concentrations of Cu (50 and 100 mg/kg) had no significant effect (p?>?0.05) on the development of phenanthrene catabolism; however, at higher Cu concentrations, the development of phenanthrene catabolism and bacterial cell numbers were significantly reduced (p?<?0.05). This suggests that Cu is more toxic than Zn to soil microbial PAH catabolic activity. Metal/PAH-contaminated soils represent one of the most difficult remedial challenges and insights into PAH biodegradation in the presence of metals is necessary in order to assess the potential for bioremediation.  相似文献   

4.
This paper presents a study that aims at evaluating the leaching characteristics of petroleum contaminated soils as well as their application in hot mix asphalt concrete. Soil samples are environmentally characterized in terms of their total heavy metals and hydrocarbon compounds and leachability. The total petroleum hydrocarbon (TPH) present in the PCS before and after treatment was determined to be 6.8% and 5.3% by dry weight, indicating a reduction of 1% in the TPH of PCS due to the current treatment employed. Results of the total heavy metal analysis on soils indicate that the concentrations of heavy metals are lower when extraction of the soil samples is carried out using hexane in comparison to TCE. The results show that the clean soils present in the vicinity of contaminated sites contain heavy metals in the following decreasing order: nickel (Ni), followed by chromium (Cr), zinc (Zn), copper (Cu), lead (Pb), and vanadium (V). The current treatment practice employed for remediation of the contaminated soil reduces the concentrations of nickel and chromium, but increases the concentrations of all remaining heavy metals.  相似文献   

5.
In the past several years, industrial and agricultural activities have led to serious environmental pollution, resulting in a large number of contaminated sites. As a result, much recent research activity has focused on the application of bioremediation technologies as an environmentally friendly and economically feasible means for decontamination of polluted soil. In this study horse manure and Populus nigra (var. italica) (HM + P treatment) have been used, at real scale level, as an approach for bioremediation of a soil historically contaminated by metals (Pb, Cr, Cd, Zn, Cu and Ni) and organic contaminants, such as polychlorobiphenyls and petroleum hydrocarbon. After one year, the HM + P phytotreatment was effective in the reclamation of the polluted soil from both organic and inorganic contaminants. A reduction of about 80% in total petroleum hydrocarbon (TPH), and 60% in polychlorobiphenyls (PCBs) and total metals was observed in the HM + P treatment. In contrast, in the horse manure (HM) treatment, used as control, a reduction of only about 30% of TPH was obtained. In order to assess both effectiveness and evolution of the remediation system to a biologically active soil ecosystem, together with the pollution parameters, the parameters describing the evolution of the soil functionality (enzymatic activities and protein SDS-PAGE pattern) were investigated. A stimulation of the metabolic soil processes (increase in dehydrogenase activity) was observed in the HM + P compared to the HM treatment. Finally, preliminary protein SDS-PAGE results have permitted the identification of proteins that have been recovered in the HM + P soil with respect to the HM; this may become a basic tool for improving the biogeochemical status of soil during the decontamination through the identification of microbial populations that are active in soil decontamination.  相似文献   

6.
Soil vapor extraction (SVE) and bioremediation (BR) are two of the most common soil remediation technologies. Their application is widespread; however, both present limitations, namely related to the efficiencies of SVE on organic soils and to the remediation times of some BR processes. This work aimed to study the combination of these two technologies in order to verify the achievement of the legal clean-up goals in soil remediation projects involving seven different simulated soils separately contaminated with toluene and xylene. The remediations consisted of the application of SVE followed by biostimulation. The results show that the combination of these two technologies is effective and manages to achieve the clean-up goals imposed by the Spanish Legislation. Under the experimental conditions used in this work, SVE is sufficient for the remediation of soils, contaminated separately with toluene and xylene, with organic matter contents (OMC) below 4 %. In soils with higher OMC, the use of BR, as a complementary technology, and when the concentration of contaminant in the gas phase of the soil reaches values near 1 mg/L, allows the achievement of the clean-up goals. The OMC was a key parameter because it hindered SVE due to adsorption phenomena but enhanced the BR process because it acted as a microorganism and nutrient source.  相似文献   

7.
The pot experiments were conducted to evaluate the effect of different concentrations of arsenic, chromium and zinc contaminated soils, amended with biosludge and biofertilizer on the growth of Jatropha curcas which is a biodiesel crop. The results further showed that biosludge alone and in combination with biofertilizer significantly improved the survival rates and enhanced the growth of the plant. With the amendments, the plant was able to grow and survive upto 500, 250 and 4,000 mg kg(-1) of As, Cr and Zn contaminated soils, respectively. The results also showed that zinc enhanced the growth of J. curcas more as compared to other metals contaminated soils. The heavy metal accumulation in plant increased with increasing concentrations of heavy metals in soil, where as a significant reduction in the metal uptake in plant was observed, when amended with biosludge and biofertilizer and biosludge alone. It seems that the organic matter present in the biosludge acted as metal chelator thereby reducing the toxicity of metals to the plant. Findings suggest that plantation of J. curcas may be promoted in metal contaminated soils, degraded soils or wasteland suitably after amending with organic waste.  相似文献   

8.
The aims of this study were to characterize soils from industrial sites by combining physicochemical, microbiological, and ecotoxicological parameters and to assess the suitability of these assays for evaluation of contaminated sites and ecological risk assessment. The soil samples were taken from long-term contaminated sites containing high amounts of heavy metals (sites 1 and 2) or petroleum hydrocarbons (site 3) located in the upper Silesia Industrial Region in southern Poland. Due to soil heterogeneity, large differences between all investigated parameters were measured. Microbiological properties revealed the presence of high numbers of viable hetrotrophic microorganisms. Soil enzyme activities were considerably reduced or could not be detected in contaminated soils. Activities involved in N turnover (N mineralization and nitrification) were significantly (P?<?0.05) higher in samples from the metal-contaminated sites than in samples from the hydrocarbon-contaminated site, whereas the opposite was observed for phosphatase activity. The Microtox test system appeared to be the most appropriate to detect toxicity and significant differences in toxicity between the three sites. The Ostracodtoxkit test was the most appropriate test system to detect toxicity in the hydrocarbon-contaminated soil samples. Correlation analysis between principal components (obtained from factor analysis) determined for physicochemical, microbiological, and ecotoxicological soil properties demonstrated the impact of total and water-extractable contents of heavy metals on toxicity.  相似文献   

9.
Genotoxicity potential of soils taken from wastewater irrigation areas and bioremediation sites was assessed using the Vicia faba root tip micronucleus assay. Twenty five soils were tested, of which 8 were uncontaminated soils and taken as the control to examine the influence of soil properties; 6 soils were obtained from paddy rice fields with a history of long-term wastewater irrigation; 6 soils were obtained from bioremediation sites to examine effects of bioremediation; and 5 PAH-contaminated soils were used to examine methodological effects between direct soil exposure and exposure to aqueous soil extracts on micronuclei (MN) frequency ( per thousand) in the V. faba root tips. Results indicate that soil properties had no significant influences on MN frequencies (p > 0.05) when soil pH varied between 3.4 to 7.6 and organic carbon between 0.4% and 18.6%. The MN frequency measured in these control soils ranged from 1.6 per thousand to 5.8 per thousand. MN frequencies in soils from wastewater irrigation areas showed 2- to 48-fold increase as compared with the control. Soils from bioremediation sites showed a mixed picture: MN frequencies in some soils decreased after bioremediation, possibly due to detoxification; whereas in other cases remediated soils induced higher MN frequencies, suggesting that genotoxic substances might be produced during bioremediation. Exposure to aqueous soil extracts gave a higher MN frequency than direct exposure in 3 soils. However, the opposite was observed in the other two soils, suggesting that both exposure routes should be tested in case of negative results from one route. Data obtained from this study indicate that the MN assay is a sensitive assay suitable for evaluating genotoxicity of soils.  相似文献   

10.
Crude oil exploration and production has been the largest anthropogenic factor contributing to the degradation of Momoge Wetland, China. To study the effects of crude oil on wetland soils, we examined the total petroleum hydrocarbon (TPH), total organic carbon (TOC), total nitrogen (TN), and total phosphorus (TP), as well as pH and electricity conductivity (EC) from oil sites and uncontaminated areas in the Momoge Wetland. All contaminated areas had significantly higher (p < 0.05) contents of TPH and TOC, but significantly lower (p < 0.05) TN contents than those of the uncontaminated areas. Contaminated sites also exhibited significantly higher (p < 0.05) pH values, C/N and C/P ratios. For TP contents and EC, no significant changes were detected. The level of soil contamination and impact of oil residuals on soil quality greatly depended on the length of time the oil well was in production. Oil residuals had caused some major changes in the soils’ chemical properties in the Momoge Wetland.  相似文献   

11.
The present investigation studies the effects of cow and chicken manure and sewage sludge at different rates of addition and with two irrigation waters of different salinities on two major calcareous soils in Bahrain. The aim was to quantify potential improvements in soil quality, the accumulation of trace metals, and quality of leachates.From the pot experiments it was found that soil waterholding capacity did not change significantly after addition of organic amendments, except in the case of sewage sludge. Total organic carbon and total Kjeldhal nitrogen content increased in the 0–5 cm layer. Low salinity water and sewage applications improved aggregate stability. Extractable phosphorus was enhanced by the chicken manure treatment more than others. Addition of different organic amendments did not affect exchangeable cations. pH values did not show appreciable changes and soils were neutral. Trace metals studied were present at non-toxic levels in the 0–5 cm layer. Zinc and copper were the only metal showing a tendency to leach to the lower soil layer. In all cases metal levels in the surface layer were proportional to the quantities added in the amendments and their levels in the leachate were very low.  相似文献   

12.
An exploratory study of the area surrounding a historical Pb?CZn mining and smelting area in Zawar, India, detected significant contamination of the terrestrial environment by heavy metals. Soils (n?=?87) were analyzed for pH, EC, total organic matter (TOM), Pb, Zn, Mn, and Cd levels. The statistical analysis indicated that the frequency distribution of the analyzed parameters for these soils was not normal. The median concentrations of metals in surface soils were: Pb 420.21 ?? g/g, Zn 870.25 ?? g/g, Mn 696.70 ?? g/g, and Cd 2.09 ?? g/g. Zn concentrations were significantly correlated with Cd (r?=?0.867), indicating that levels of Cd are dependent on Zn. However, pH, electrical conductivity and total organic matter were not correlated significantly with Cd, Pb, Zn, and Mn. To assess the potential mobility of Cd, Pb, and Zn in soils, single (EDTA) as well as sequential extraction scheme (modified BCR) were applied to representative (n?=?23) soil samples. The amount of Cd, Pb, and Zn extracted by EDTA and their total concentrations showed linear positive correlation, which are statistically significant (r values for Cd, Pb, and Zn being 0.901, 0.971, and 0.795, respectively, and P values being <0.001). The correlation coefficients indicate a strong relation between EDTA-extractable metal and total metal. These results appear to justify the use of ??total?? metal contents as a useful preliminary indicator of areas where the risks of metal excess or deficiency are high. The EDTA extractability was maximum for Cd followed by Pb and Zn in soils from all the locations. As indicated by single extraction, the apparent mobility and potential bioavailability of metals in soils followed the order: Cd ?? Pb >?> Zn. Soil samples were sequentially extracted (modified BCR) so that solid pools of Cd, Zn, and Pb could be partitioned into four operationally defined fractions viz. acid-soluble, reducible, oxidizable, and residual. Cadmium was present appreciably (39.41%) in the acid-soluble fraction and zinc was predominantly associated (32.42%) with residual fraction. Pb (66.86%) and Zn (30.44%) were present mainly in the reducible fraction. Assuming that the mobility and bioavailability are related to solubility of geochemical forms of metals and decrease in the order of extraction, the apparent mobility and potential metal bioavailability for these contaminated soil samples is Cd > Zn > Pb.  相似文献   

13.
This study aimed to assess soil quality by chemical and ecotoxicological investigations and to check the correspondence between soil metal concentrations and ecotoxicity. For these purposes, surface soils collected at four adjacent roadside urban parks and at a former industrial area were characterized for C/N, organic matter content, texture, and pH. Cr, Cu, Ni and Pb, chosen among the most representative soil metal contaminants, were measured as total content and as available and water soluble fractions. In addition, the total concentrations of the investigated metals were used to calculate two chemical indices: the contamination and the potential ecological risk factors. The toxicity of the investigated soils was evaluated by an ecotoxicity test battery carried out on both soil samples (Vibrio fischeri, Heterocypris incongruens and Sinapis alba) and elutriates (Vibrio fischeri, Daphnia magna and Selenastrum capricornutum). The findings, both by the chemical and ecotoxicological approaches, would suggest that the soils with high metal contamination pose ecological risks. On the other hand, moderately metal contaminated soils did not exclude soil ecotoxicity. In fact, toxic effects were also highlighted in soils with low metal content, toxicity being affected by metal availability and soil characteristics. Moreover, the results suggest the importance of using a battery of tests to assess soil ecotoxicity.  相似文献   

14.
Biodegradation has been identified as a major loss process for organic contaminants in soils and, as a result, microbial strategies have been developed for the remediation of contaminated land. Prediction of the biodegradable fraction would be important for determining bioremediation end-points in the clean-up of contaminated land. The aim of this study was to investigate the ability of a cyclodextrin extraction to predict the extent to which polycyclic aromatic hydrocarbons (PAHs) would be degraded microbiologically in field contaminated soils; further testing the robustness and reproducibility of this extraction in chemically complex systems. Dichloromethane and hydroxypropyl-beta-cyclodextrin (HPCD) extractable fractions were measured together with the PAH biodegradable fraction in each of the six field contaminated soils. The amounts of PAHs degraded by the catabolic activity of the indigenous microflora in each of the soils were correlated with HPCD-extractable PAH concentrations. The regressions showed that the amounts of lower molecular weight PAHs extracted by the HPCD were not significantly (P > 0.05) different to the amounts that were degraded. However, higher molecular weight PAHs that were extracted by HPCD did differ significantly (P < 0.05) from the amounts degraded. Although the HPCD extraction did overestimate the microbially degradable fraction of the higher molecular weight PAHs, overall the correlations between the HPCD extractable fraction and the microbially degradable fraction were very close, with mean values of the slope of line for the six soils equalling 1. This study further describes the robust and reproducible nature of the aqueous-based soil extraction technique reliably measuring the extent to which PAHs will be microbially degraded in soil.  相似文献   

15.
The assessment of soil quality after a chemical or oil spill and/or remediation effort may be measured by evaluating the toxicity of soil organisms. To enhance our understanding of the soil quality resulting from laboratory and oil field spill remediation, we assessed toxicity levels by using earthworms and springtails testing and plant growth experiments. Total petroleum hydrocarbons (TPH)-contaminated soil samples were collected from an oilfield in Sfax, Tunisia. Two types of bioassays were performed. The first assessed the toxicity of spiked crude oil (API gravity 32) in Organization for Economic Co-operation and Development artificial soil. The second evaluated the habitat function through the avoidance responses of earthworms and springtails and the ability of Avena sativa to grow in TPH-contaminated soils diluted with farmland soil. The EC50 of petroleum-contaminated soil for earthworms was 644 mg of TPH/kg of soil at 14 days, with 67 % of the earthworms dying after 14 days when the TPH content reached 1,000 mg/kg. The average germination rate, calculated 8 days after sowing, varied between 64 and 74 % in low contaminated soils and less than 50 % in highly contaminated soils.  相似文献   

16.
Soil microbial ecosystems are responsive to environmental changes that underpin the biological functions of the soil. The present study was conducted to profile variations in the microbial ecological system of remediated soil (R) and petroleum contaminated soil (P) based on comparisons with soil that had not been contaminated (N), using a cloning library of taxonomic genes (16S rRNA gene for bacteria and 18S rRNA gene for eukaryotes) and functional genes (nifH, amoA and narG). The results showed that N and R had a similar distribution in both the taxonomic genes and functional genes for bacteria and eukaryotes, which were dominated by Proteobacteria and Arthropoda, respectively. Phylogenetic analysis based on the nifH gene showed that the sequences from the three soils were clustered into six taxonomic groups, Actinobacteridae, and Alpha-, Beta-, Gamma- and Delta-proteobacteria, as well as an unclassified group. Evaluation of the amoA gene revealed that all sequences derived from the three samples belonged to Betaproteobacteria. The R and N soil had similar Shannon-Wiener diversity index (H') values, both of which were significantly higher than that of the P soil. The most abundant bacterial phylotype identified in the N and R soils were the same and were related to an uncultured bacterial clone (GAN-SB17, FN423475). None of the narG genes were found in the P soil. Similar results in terms of distribution, composition and the related index were obtained for nifH and amoA. These parameters may comprise a biological ecology index that may be applied to aid the design, implementation and evaluation of soil bioremediation.  相似文献   

17.
The abilities of sorghum (Sorghum bicolor L.) and oat (Avena sativa L.) to take up heavy metals from soils amended with ethylenediaminetetraacetic acid (EDTA) were assessed under greenhouse conditions. Both plants were grown in two soils contaminated with heavy metals (Gujranwala—silty loam and Pacca—clay loam). The soils were treated with 0, 0.625, 1.25, and 2.5 mM EDTA kg?1 soil applied at both 45 and 60 days after sowing (DAS); the experiment was terminated at 75 DAS. Addition of EDTA significantly increased concentrations of Cd, Cr, and Pb in roots and shoots, and bio-concentration factors and phytoextraction rates were also increased. Post-harvest soil analysis showed that soluble fractions of metals were also increased significantly. The increase in Cd was ≈ 3-fold and Pb was ≈ 15-fold at the highest addition of EDTA in Gujranwala soil; in the Pacca soil, the increase was less. Similarly, other phytoremediation factors, such as metal translocation, bio-concentration factor, and phytoextraction, efficiency were also maximum when soils were treated with 2.5 mM EDTA kg?1 soil. The study demonstrated that sorghum was better than oat for phytoremediation.  相似文献   

18.
Biomarker responses and histopathological lesions have been documented in laboratory mammals exposed to elevated concentrations of lead and cadmium. The exposure of white-footed mice (Peromyscus leucopus) to these metals and the potential associated toxic effects were examined at three contaminated sites in the Southeast Missouri Lead Mining District and at a reference site in MO, USA. Mice from the contaminated sites showed evidence of oxidative stress and reduced activity of red blood cell δ-aminolevulinic acid dehydratase (ALAD). Histological examinations of the liver and kidney, cytologic examination of blood smears, and biomarkers of lipid peroxidation and DNA damage failed to show indications of toxic effects from lead. The biomagnification factor of cadmium (hepatic concentration/soil concentration) at a site with a strongly acid soil was 44 times the average of the biomagnification factors at two sites with slightly alkaline soils. The elevated concentrations of cadmium in the mice did not cause observable toxicity, but were associated with about a 50% decrease in expected tissue lead concentrations and greater ALAD activity compared to the activity at the reference site. Lead was associated with a decrease in concentrations of hepatic glutathione and thiols, whereas cadmium was associated with an increase. In addition, to support risk assessment efforts, we developed linear regression models relating both tissue lead dosages (based on a previously published a laboratory study) and tissue lead concentrations in Peromyscus to soil lead concentrations.  相似文献   

19.
This study describes the first attempt to validate a Portuguese natural soil (PTRS1) to be used as reference soil for ecotoxicological purposes, aimed to both: (i) obtain ecotoxicological data for the derivation of Soil Screening Values (SSVs) with regional relevance, acting as a substrate to be spiked with ranges of concentrations of the chemicals under evaluation and (ii) act as control and as substrate for the dilution of contaminated soils in ecotoxicological assays performed to evaluate the ecotoxicity of contaminated soils, in tier 2 of risk assessment frameworks, applied to contaminated lands. The PTRS1 is a cambisol from a granitic area integrated in the Central Iberian Zone. After chemical characterization of the soil in terms of pseudo-total metals, PAHs, PCBs and pesticide contents, it was possible to perceive that some metals (Ba, Be, Co, Cr and V) surpass the Dutch Target Values (Dtvs) corrected for the percentage of organic matter and clay of the PTRS1. Nevertheless, these metals displayed total concentrations below the background total concentrations described for Portuguese soils in general. The same was observed for aldrin, endosulfan I, endosulfan II, heptachlor epoxide, and heptachlor; however the Dtvs corrected become negligible. The performance of invertebrate and plant species, commonly used in standard ecotoxicological assays, was not compromised by both soil properties and soil metal contents. The results obtained suggest that the PTRS1 can be used as a natural reference soil in ecotoxicological assays carried out under the scope of ecological risk assessment.  相似文献   

20.
Nickel is a heavy metal which is a stable soil pollutant which is difficult to remediate. An attempt to reduce its impact on the environment can be made by changing its solubility. The right level of hydrogen ions and the content of mineral and organic colloids are crucial in this regard. Therefore, methods to neutralise heavy metals in soil are sought. There are no reports in the literature on the possibility of using minerals in the detoxication of a soil environment contaminated with metals. It is important to fill the gap in research on the effect of zeolites on the microbiological, biochemical and physicochemical properties of soils under pressure from heavy metals. Therefore, a pot experiment was conducted on two soils which examined the effect of various levels of contamination of soil with nickel on the activity of soil enzymes, physical and chemical properties and growth and development of plants. An alleviating effect of zeolite Bio.Zeo.S.01 on the negative impact of nickel on the soil and a plant (oats) was examined. The enzyme activity and the oat yield were found to be significantly and negatively affected by an excess of nickel in the soil, regardless of the soil type. The metal was accumulated more in the oat roots than in the above-ground parts. An addition of zeolite decreased the level of accumulation of nickel in oats grown only on sandy-silty loam. Zeolite Bio.Zeo.S.01 used in the study only slightly alleviated the negative effect of nickel on the biochemical properties of soil. Therefore, its usability in the remediation of soil contaminated with nickel is small.  相似文献   

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