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1.
应用水葫芦去除电镀废水中重金属的研究   总被引:24,自引:1,他引:23  
应用水葫芦去除电镀废水中重金属的研究李卫平,王军,李文,王俊初(中国人民解放军总后节能环保中心武汉430033)ApplicationofWaterHyacinthtotheRemovalofHeavyMetalsfromElectroplateWa...  相似文献   

2.
Concentrations of Pb, Zn, Cd, Cu, Cr, Co, and Ni were determined in roadside topsoil collected from locations of varied vehicular traffic densities in the city of Ibadan, Nigeria, with a view to determining the level of contamination and the contribution of traffic density. Levels of Pb, Zn, Cd, and Cu were elevated above background concentrations measured in control areas. Average values (ppm) for all sample locations were Pb — 81±140; Zn — 48±37; Cd — 0.55±0.49; Cu — 17±17; Cr — 22.1±9.6; Co — 7.9±3.8; Ni — 10.5±9.7. Factors of accumulation of metals in roadsides relative to control sites were highest for Pb. Vehicular traffic was not an important source of chromium, cobalt and nickel, for which roadside concentrations were about those of the control sites. Metal concentrations were poorly correlated with traffic volumes. An average of about 60% of total soil concentration of the metals were determined to be held in bioavailable geochemical phases, of which the highest concentrations were mostly held in either the reducible or oxidizable phase. Levels of the metals in the topsoil were generally lower than the soil quality criteria of some developed countries.  相似文献   

3.
A survey was made of 168 specimens of the gastropod mollusk Nucella heyseanafrom 5 samples collected in Amurskii Bay and Vostok Bay (Peter the Great Bay and the Sea of Japan). The variability of Cu, Zn, Cd, Pb, Fe, and Mn contents in gastropod soft tissues was analyzed. The statistic concentrations of the six metals differed significantly among the samples; they were sometimes taken at a distance of a mere several tens of meters apart. N. heyseanacollected near Vladivostok generally had higher concentrations of heavy metals; however, the amount of Zn in the specimens of one sample from the Vostok Bay Reserve was 400 g/g, which is two times greater than that of mollusks from the urbanized zone. The canonical and discriminant analyses and the analysis of the variance indicate that the variation in heavy metal concentration within groups of mollusks (within bays) is comparable in magnitude with the variation among the groups.  相似文献   

4.
Soil distribution of heavy metals caused by municipal solid waste (MSW) deposition and its implications for MSW management system in emerging cities was investigated in Abeokuta, Nigeria. Results indicated that the highest concentrations of Cu, Cr, Mn, and Zn were observed at 0-40 cm while Pb, Fe, and Ni accumulated at depths below 40 cm. Soils affected by waste deposits from market and auto-mechanic sites showed high levels of Fe, Cr, Pb, Cu, Mn, and Zn. The accumulation of heavy metals in the soils was probably due to the formation of metal-organo-complexes. Therefore, source separation of MSW with proper management systems is proposed to improve the indiscriminate surface dumping practiced at present, while the use of wastes affected sites for cultivation should be discouraged.  相似文献   

5.
This article describes the removal of heavy metals from contaminated clayey soils by soil washing using various extractants. Two clayey soils, kaolin, a low buffering soil with pH of 5, and glacial till, a high buffering soil with pH of 8, were used to represent various soil conditions. These soils were spiked with chromium (Cr), nickel (Ni), and cadmium (Cd) to simulate improper disposal of typical electroplating waste constituents. The following extracting solutions were investigated for the removal of heavy metals from the soils: deionized water, distilled water, and tap water; acetic acid and phosphoric acid; chelating agents ethylenediaminetetraacetic acid (EDTA) and citric acid; and the oxidizing agents potassium permanganate and hydrogen peroxide. The effect of extractant concentration on removal of heavy metals was also investigated. Complete removal of Cr was achieved using 0.1?M potassium permanganate for kaolin, while a maximum of 54% was removed from glacial till. A maximum Ni removal of 80% was achieved using tapwater for kaolin, while a maximum removal of 48 to 52% was achieved using either 1?M acetic acid or 0.1?M citric acid for glacial till. A maximum Cd removal of 50% was achieved using any of the extractants for kaolin, while a maximum removal of 45 to 48% was obtained using either acids or chelating agents for glacial till. Overall, this study showed that complete removal of Cr, Ni, and Cd from clayey soils is difficult to achieve using the soil-washing process, and also the use of one extractant may not be effective in removing all metals. A sequential extraction using different extractants may be needed for the removal of multiple metal contaminants from clayey soils.  相似文献   

6.
Heavy metals and As in rice are of increasing concern in China. In this study, concentrations of Pb, Cd, Cu, Cr, Sb, Ni, and As in rice collected from markets in Fuzhou, China, were investigated by ICP-MS and AFS, and their potential health risk to inhabitants were estimated by target hazard quotient (THQ), hazard index (HI), and target cancer risk (TR). The results showed that the concentrations of the seven studied elements in rice grain were all below the permissible limits of China's national standards for foodstuffs (NY/T 419–2007 and GB 2726–2012). For non-carcinogenic risk, the THQ values of individual elements were within the safe interval. However, without considering the bio-accessibility and speciation of toxic elements, the HI values suggest inhabitants in Fuzhou may experience potential health effects due to rice consumption. Cadmium is the major contributor to HI, followed by As. The TR values of As for adults and children were both higher than the acceptable range. The results of this study suggest that more attention should be paid toward monitoring toxic substances (especially Cd and As) in rice in order to assure the food safety for consumers in Fuzhou, China.  相似文献   

7.
Several Lupinus species, for example, Lupinus albus, Lupinus luteus, Lupinus angustifolius, and Lupinus hispanicus were used to accumulate Mn(II), Cd(II), Pb(II), Cr(III), Cr(VI), Hg2+, and CH3Hg+ from waste waters. The influence of different species concentrations (50 and 100 mg L-1) and pH on growing behavior as well as the resulting distribution of metals in the plants were investigated. The results obtained showed that lupins were able to germinate and to grow in the presence of the metals mentioned above, even when they were present at levels as high as 50 mg L-1. Accumulation of Pb(II), Cr(III), and Cd(II) was higher in roots than in shoots. As far as mercury is concerned, the highest CH3Hg and Hg2+ accumulation was detected in roots, but fast transport toward the leaves was noticed. In contrast to mercury, the uptake of chromium seems to be influenced by the chemical form of the analyte, remaining Cr(VI) in solution. No differences in growing behavior and accumulation were observed for the four Lupinus species studied. Even though plants were exposed only a relatively short time to the metal solutions, metal concentrations of approximately 2 g/kg of dry matter were detected in the young lupins plants. The feasibility of utilizing Lupinus plants for the removal of heavy metals from wastewater was also investigated. Lupins were able to grow under extreme conditions (wastewater, pH lower than 2) and to remove 98% of the initial amount of toxic metals present in the sample.  相似文献   

8.
春玉米与生姜间作不同种植方式农田生态效应研究   总被引:4,自引:0,他引:4  
春玉米与生姜间作不同种植方式农田生态效应研究姚向高王爱玲(河南农业大学农学院,郑州450002)StudyoftheEcologicalEfcctsofDiferentTreatmentofIntercroppingofSpringMaizeand...  相似文献   

9.
Abstract: Various toxic, useful, and/or scarce metals in waste electric and electronic equipment (WEEE) have rarely been assessed due to low data availability, except for the four metals regulated by the European Union's Directive on the Restriction of Hazardous Substances (RoHS). This article describes the results of screening 36 metals in WEEE using simple assessment methods for cases where the decision makers do not know for which substances in a product countermeasures should be taken and where data cannot be easily obtained. First, this study examines the decision-making process and prerequisites for screening, classifies existing assessment methods, and presents three simple indices for screening (resource consumption, water pollution affecting human health, and aquatic biota conservation) so that screening can be readily started for many (20–36) metals. Following this, a case study is conducted for waste TV sets, revealing which metal in which product module or component should be targeted by environmental countermeasures. Finally, the screening results are compared with those of six other methods using diagrams devised to indicate the superiority of screening methods, and several screening techniques are discussed. The conclusions are that the EU RoHS Directive does not necessarily cover all of the toxic metals that could be of concern and the screening methods presented could help identify such metals; the selection of methods is critical; and a more detailed method does not necessarily provide more accurate results.  相似文献   

10.
目的:在生物浸出中,微生物群落结构分析有着重要意义,而群落分析的基础是提取纯度高、损失少的基因组DNA。为了解决这一问题,本实验通过比较两种较常用的DNA提取方法,煮沸裂解法和试剂盒法,寻找一种灵敏、快速、经济实用的制备浸矿细菌基因组DNA的方法。方法:分别用煮沸裂解法和试剂盒法提取6种浸矿菌的基因组DNA,从所提取的基因组DNA浓度、纯度、回收率和对PCR扩增反应的影响方面比较了两种方法的提取效果;用两种方法来处理不同浓度梯度的一种菌,通过实时定量PCR来比较两种方法的灵敏性。结果:相同处理量(108个)的革兰氏阳性菌(1株)、革兰氏阴性菌(4株)、古菌(1株)经两种方法提取的基因组DNA差异较大,煮沸裂解法所得的6组基因组DNA更纯,其OD260/OD280的值更接近1.8-2.0(纯DNA的OD260/OD280在1.8-2.0之间),前者所提DNA回收率最大可达后者的16.7倍;煮沸裂解法只需较少菌(102个)便能让实时定量PCR检测到所提DNA模板浓度,比试剂盒法灵敏。结论:两种方法提取的基因组DNA均可用于后续的PCR扩增,此外,前者提取的DNA浓度随细菌浓度增加而呈线性增大,而后者随菌浓度增大,所提DNA量增加有限,因此,在生物浸出中微生物基因组DNA的提取可直接采用简单快速的煮沸提取法,为实验节约成本和时间。  相似文献   

11.
微生物展示技术在重金属污染生物修复中的研究进展   总被引:2,自引:0,他引:2  
自然界对环境金属污染物的迁移和转化具有微妙而复杂的选择控制机理,生物修复技术以其投资少、效率高、可以原位处理低浓度有害污染物的特性而在环境治理中具有极大潜力。考虑传统的生物修复技术常常不能满足重金属治理的要求,基于重金属离子高效结合肽的微生物展示技术,有望在重金属生物修复中发挥重要作用。  相似文献   

12.
This study evaluated the effect of composted cow manure (CCM) on the chemical fractionation and retention degree of heavy metals (HMs) in mine tailings from Zimapán, México. In a greenhouse experiment, mine tailings from three deposits were incubated for 3 months; experimental units were placed in a PVC container, where increasing doses of CCM were applied. HM pseudo-total concentrations, HM extractions with ethylenediaminetetraacetic acid (EDTA, 0.05 M), and a sequential chemical extraction (SCE) were carried out. The HM concentrations were determined by atomic absorption spectrophotometry. The pseudo-total concentrations of Pb, Cu, Cd, and Ni found were up to 1506, 206, 27, and 23 mg kg?1, respectively; extractable Pb was up to 42%; 21% for Cu; 51% for Cd; and 16% of Ni of the pseudo-total concentrations of each metal. Treatment with 12% of CCM in mine tailing decreased EDTA-extractable HM concentrations, while the SCE revealed a decrease in exchangeable fraction and an increase in the organic fraction of HM. A positive correlation between CCM application and organic fractions of HMs was found, although the highest increasements were recorded in the organic fraction.  相似文献   

13.
The concentrations of iron, copper, zinc, manganese, cadmium, and mercury in tissues and organs of Pacific herring, Far Eastern navaga, and spotted flounder from Amurskii Bay, Sea of Japan, were determined using an atom-absorption method. The distribution of these elements has been studied in organisms of the fish. The greatest concentration of iron, copper, cadmium, and mercury is found in the liver of the fish, manganese is mostly accumulated in the bone tissue, and zinc is found in the skin. Some specific features of metal accumulation in the fish of Amurskii Bay have been revealed. For example, the concentration of iron in the liver of herring and flounder significantly increased the mean concentration known from other areas. A sanitary–hygienic evaluation is provided for the recent levels of metal concentrations in these three species of commercially important fish.  相似文献   

14.
Soils of the urban and suburban area of Belgrade have been hardly studied, especially concerning their concentrations of potentially toxic metals. The present paper is aimed at determining the possible pollution in soils. The total acid soluble concentrations of heavy metals and As in the samples were determined. It was found that they were arranged in the order Zn > Ni > Pb > Cr > Cu > As > Hg > Cd in samples collected in the examined area (the order of the elements is based on their arithmetic mean concentrations). In all the samples collected at 0–10 and 40–50 cm depths from 46 selected sites, the contents of Pb and Zn were lower at the depth 40-50 cm. Using target values given by the Dutch Ministry of Housing, Spatial Planning and Environment, it may be concluded that Belgrade soil can, for the most part, be regarded as unpolluted. Traffic seems to be one of the main sources of these metals, but the influence of other factors cannot be excluded.  相似文献   

15.
利用模拟池塘微生态系统开展长期暴露毒性实验,研究了铜矿尾矿砂中重金属在各个环境介质中的迁移及其生物有效性,实验结果较好地反映尾矿库湿地系统中重金属的生物毒性作用与生物可利用性,结果表明的重金属浓度会刺激生物生长与繁殖,而过高的重金属浓度则对生物的生长繁殖具有明显的毒性作用。微生态系统各组份间的重金属含量与尾矿砂中重金属含量具有良好的相关性,生物体内重金属累积与底泥尾矿砂中重金属浓度,种类和生物类属有关,试验研究为矿山生态修复过程的湿地利用提供重要的科学依据。  相似文献   

16.
In recent years forecasting soil cleaning efficiencies of polluted soil, especially those contaminated with heavy metals, has become an important issue. Failure of the methods to predict the right efficiency has resulted in financial losses and penalties. This article describes an addition to the traditional characterization methods for soils contaminated by heavy metals, improving the quality of the basic decisions to be made. The method is based on magnetic separation using a Frantz Isodynamic Separator (FIS) for this study. The FIS isolates soil particles containing heavy metals so that these particles, which are relevant for soil cleaning, can be studied in more detail. Four contaminated soils were tested, for example, soils that were a problem for the soil-cleaning industry. The experiments indicate that each soil has its own magnetic properties that should be regarded as a fingerprint. Density measurements of two soils show that densities approach the quartz density separated at moderate and high magnetic fields suggesting that some of the heavy metals cannot be removed by density separation techniques. A pilot plant scale test supports this conclusion. It also shows that a part of the heavy metals are found in particles lighter than quartz. Based on the results, a qualitative model is proposed to account for the presence of the heavy metals in soil.  相似文献   

17.
Heavy metals’ origin, accumulation, and distribution in soil have been the focus of much attention by many researchers. The objective of this study was to recognize the sources of heavy metals in surface soils in Hamadan Province in western Iran using multivariate geostatistical techniques. A total of 263 surface (0–10 cm) soil samples and 18 rock samples from major parent materials were collected. Cobalt (Co), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb), and zinc (Zn) contents of the samples were determined. Selected soil physical and chemical characteristics were also measured. A multivariate geostatistical analysis was performed to identify the common source of heavy metals. The quantities of Co, Cr, and Ni were found to be associated with parent rocks, corresponding to the first factor termed the “lithologic component.” The second factor was mainly attributed to Cu, which also comprised the first and third factors, indicating a mixed source both from lithologic and anthropogenic inputs. Zn and Pb contents were related to the anthropogenic activities and comprised the third factor. A significant correlation was found between metals from the lithogenic sources and selected soil properties such as soil organic matter, clay, CEC, and carbonate, indicating an interaction among them. Generally, Zn and Pb showed a less significant correlation with soil properties.  相似文献   

18.
This study assesses the contents of heavy metals in the four most commonly used indigenous medicinal plants in the Bannu District, Pakistan. The rapid appraisal approach was used along with semi-structured interviews with elderly people and herbalists for selection of indigenous plants. Heavy metals were determined via flame atomic absorption spectrometer by acid digestion of samples. Four medicinal plants were selected after interviews of 53 local residents and herbalists. Plant and soil samples were obtained for evaluations from a wastewater zone (WWZ) and a clean water zone (CWZ). Indigenous plants from the WWZ showed considerably higher metal contents compared to the CWZ. The trend of metals for indigenous medicinal plants grown in clean water was Mn > K > Na > Zn > Co > Fe > Cu while for wastewater the trend appeared as Co > K > Na > Zn > Fe > Mn > Cu. An alternative significant extent of research is needed to qualify the assessment of the human health insinuations of consumption of indigenous remedies. The heavy metal content of administering herbal medicine should be screened, as formulation and processing of medicine may affect heavy metal contents of the remedies.  相似文献   

19.
富营养化与污染物间的相互作用及其生态效应   总被引:11,自引:2,他引:11  
1 引 言进入 90年代 ,为了改善水环境条件 ,越来越多的国家认识到必须减少养分、稳定的有机物和金属元素的输入。富营养化和持续污染物 (Chronicpollutants)是当前全球水生态系统的两个主要问题[1 ,2 ]。尽管对富营养化和污染物已有很多研究 ,但很少调查二者之间的相互关系。有证据表明两者之间可能存在相互作用过程[5~ 7],但在自然的水生态系统中其作用的大小和关系尚不清楚。滇池是我国典型的遭受富营养化和重金属污染双重胁迫的高原湖泊 ,本研究以滇池富营养化和重金属污染为背景 ,通过室内模拟 ,初步探索富营养化和…  相似文献   

20.
Field and laboratory research has repeatedly shown that free-living soil nematodes differ in their sensitivity to soil pollution. In this paper, we analyze whether nematode genera proved sensitive or tolerant toward heavy metals and organic pollutants in six long-term field experiments. We discuss overlaps between nematode physiological responses to heavy metals and to organic pollutants, which may explain why nematodes can exhibit co-tolerance toward several contaminants. We propose a simple method for separating direct effects of soil contamination on nematode populations from indirect effects mediated through the food chain. Finally, we analyze the extent to which nematodes exhibited consistent responses across the experiments analyzed. Our results show that (a) indirect effects of pollution were generally strong; (b) fewer nematode genera were tolerant than sensitive; (c) many genera, including practically all Adenophorea, exhibited a common response pattern to contaminants; and (d) several genera of the Secernentea exhibited differential tolerance toward particular pollutants. We conclude that bioindication of soil contamination should preferentially be based on tolerant, and less on sensitive, nematodes. We provide a list of nematode genera that may potentially serve as differential bioindicators for specific soil contaminants.  相似文献   

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