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1.
Abstract

Arsenic (As) contamination is widespread in the industrial areas of northwest Ohio. Plant species that both take up As and are appropriate for the climate and growth conditions of the region are needed for phytoremediation to be successfully employed. Actively growing plants from 22 species of native genera were exposed to As in hydroponics systems (either 0, 10, or 50 mg As L?1; 1 week) and commercially available potting mix (either 0, 10, 25, 100, or 250 mg As L?1; 2 weeks), depending on their growth conditions. Aboveground plant tissues were harvested and digested, and concentrations of As were determined by inductively coupled plasma–optical emission spectrometry. The highest tissue concentrations of As (mg As kg?1 dw) were recorded in seven plant species: Rudbeckia hirta (661), Helenium autumnale (363 in tissues formed after exposure to As), Lupinus perennis (333), Echinacea purpurea (298), Coreopsis lanceolata (258), Lepidium virginicum (214), and Linum lewisii (214). These seven species are ecologically diverse, which suggests that phytoremediation of As using diverse assemblages of plants may be an option for a variety of environments.  相似文献   

2.
A method that utilizes solid-phase microextraction (SPME) coupled with gas chromatography (GC) and chemical ionization tandem mass spectrometry (MS/MS) was developed for analyzing a group of emerging pollutants, N-nitrosamines, in water. The developed analytical method requires a water sample of less than 5 ml and only 1.5 h for complete analysis. The method detection limits for N-nitrosodimethylamine (NDMA), N-nitrosodiethylamine, and N-nitrosodi-n-propylamine were in the range of 3.2 to 3.5 ng/l; for N-nitrosomorpholine, it was 15.2 ng/l. The method was successfully employed to measure the N-nitrosamine concentration at trace levels of nanogram per liter in four water treatment plants (WTPs) and one water distribution system. In the WTPs, only NDMA was detected in the treatment processes. Within the treatment train, NDMA was observed after chlorination. The level of NDMA significantly declined after slow sand filtration due presumably to microbial degradation. The NDMA concentration collected from consumer tap water was about 40% higher on average than that in the finished water. The excellent performance of the SPME/GC/MS/MS method in various water matrices as well as the shorter analysis time and smaller sample volume compared to currently used extraction techniques makes it an alternative means for the analysis of N-nitrosamine in drinking water, wastewater, and laboratory research with small reactors.  相似文献   

3.
An ultrasonic method using two approaches, A and B, along with a reference Environmental Protection Agency (EPA) Method 3050B [i.e., a mixture of 30 mL of nitric acid–hydrochloric acid–hydrogen peroxide–water (HNO3-HCl-H2O2-H2O)] were contrasted for leaching of a plant matrix. The trace metals were arsenic, cadmium, cobalt, chromium, copper, mercury, manganese, nickel, lead, selenium, and zinc (As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, Se and Zn) and quantified by ICP-OES followed by an investigation into residue formation and the impact of digestion time. Approach B was the most accurate and precise with percent recoveries ranging between 99 and 120%, whereas ultrasonic approach A and the USEPA method 3050B gave similar results with poor accuracies and precisions. In the optimization of the digestion time using approach B, the total metal recovery was fairly the same over a period of 120 min except for Cr and Cu, which showed slight variations.  相似文献   

4.
Frequency of boron (B) deficiency is increasing in rainfed systems, and hence there is a need to diagnose the deficiency. Colorimetric methods are still widely used in soil-testing laboratories in India for measuring B. Little information is available on the comparative evaluation of the colorimetric and inductively coupled plasma (ICP) methods for determining extractable B in soils. We describe results of the comparative evaluation of these methods for measuring extractable B in 57 soil samples with pH values ranging from 5.3 to 9.5. There was a significant correlation between B values determined by the two methods, and the correlation coefficient was greater for soil samples with pH in the neutral to alkaline range. Interaction between soil samples and methods (ICP or colorimetric) was significant except for soil samples in the pH range of 8.0 to 9.5. Precision for B determination was greater with the ICP than with the colorimetric method.  相似文献   

5.
A long‐term (61 years) experimental field was used to examine the effect of acidification on the chemical composition of an allophanic Andisol in northeastern Japan. The pH values of the 1:10 water extract of the plow layer soils were 4.1, 4.7, and 6.2 for three fertilizer application treatments: chemical fertilizers only (CF), CF and compost (CFC), and CFC with liming, respectively. Three batch dissolution analyses were conducted to determine water‐soluble and exchangeable (D1), D1 plus, inorganically bound elements to noncrystalline clays and organically bound elements (D2), and total concentration of elements (TCE, 45 elements). The D1 fraction of 20 elements increased, and that of eight decreased with acidification. The D2 fraction of lithium increased, and that of eight elements decreased with acidification. Because the D2 fraction of many other elements and TCE were not strongly altered, present acidification of this soil can be restored with liming and other necessary amendments.  相似文献   

6.
A study was conducted for comparative evaluation of atomic absorption spectrophotometry (AAS) and inductively coupled plasma–optical emission spectroscopy (ICP-OES) for determining extractable zinc (Zn), copper (Cu), manganese (Mn), and iron (Fe) in sixty diverse soil samples having a wide range in pH and organic carbon (C). The results were significantly affected by the method of analysis and soil type but generally did not follow a definite trend. Results for extractable Fe in Alfisol samples were significantly greater when using ICP-OES than AAS; and the results for Zn, Cu, and Mn were not significantly different for the two methods. For Vertisol samples, the results for extractable Cu were significantly greater by ICP-OES than by AAS, whereas extractable Fe and Zn were significantly greater by AAS than by ICP-OES, and the results for Mn were not significantly different for the two methods. The results are discussed relative to soil type and differences in soil organic carbon and pH of the samples used in the study.  相似文献   

7.
Abstract

A previous study indicated that agricultural biosolid applications increased the concentration of EPA3050‐digestible trace elements in soils on Pennsylvania production farms but could not indicate potential trace‐element environmental availability. This study was conducted to determine if biosolid application had altered the distribution of trace‐elements among operationally defined soil fractions and the relationship of trace element concentrations in soil and crop tissues. Biosolid‐amended and unamended soils from production farms in Pennsylvania were extracted using a modified Bureau Communautaire de Référence (BCR) sequential fractionation technique and analyzed for chromium (Cr), copper (Cu), nickel (Ni), lead (Pb), and zinc (Zn). Trace‐element concentrations in crop tissues (soybean silage, sudangrass, corn grain, alfalfa hay, and orchardgrass hay) from the same farms were also determined. Fractionation results indicated that the proportion of Cr, Cu, Ni, Pb, and Zn that is potentially bioavailable is quite small in unamended soils. Biosolid applications significantly (P≤0.1) increased concentrations of Cu in all soil fractions (average increase over unamended soil=1.14, 8.27, 6.04, and 5.84 mg kg?1 for the exchangeable, reducible, oxidizable, and residual fractions, respectively), Ni (0.41, 1.65 mg kg?1 for the reducible and residual fractions, respectively), Pb (5.12 and 1.49 mg kg?1 for the reducible and residual fractions, respectively), and Zn (8.28, 7.12, 4.44, and 8.98 mg kg?1 for the exchangeable, reducible, oxidizable, and residual fractions, respectively) but did not significantly increase Cr in any soil fraction. Concentrations of Cu in all soil fractions were significantly (P≤0.01) correlated with concentrations of Cu in orchardgrass tissue (r=0.70, 0.66, 0.76, and 0.69 for the exchangeable, reducible, oxidizable, and residual soil fractions, respectively). Concentrations of exchangeable and reducible Zn were significantly correlated with Zn in sudangrass tissue (r=0.81 and 0.67), and reducible Zn was significantly correlated with Zn concentrations in orchardgrass tissue (r=0.65). Application of biosolids had little effect on bioavailability of Cr, Ni, or Pb, whereas higher loadings of Cu and Zn led to a shift toward the more labile soil fractions. Loadings of Cu and Zn were much smaller than cumulative loadings permitted under U.S. Environmental Protection Agency (USEPA) Part 503 regulations. Chemical soil fractionation was able to detect increases in labile soil Cu and Zn that relate to increased phytoavailability.  相似文献   

8.
A two-step digestion–ultraviolet (UV) spectrophotometry method for total nitrogen (N) determination in solid samples is described in this work. Three influencing factors (amount of hydrogen peroxide, amount of sulfuric acid, and digestion time) of the digestion are optimized, and for digestion of a 0.1-g solid sample, the optimal conditions are 0.5 mL of sulfuric acid, 0.2 mL of hydrogen peroxide, and 40 min of the digestion time. The results of ion chromatography show that under the optimal conditions the organic nitrogen almost quantitatively mineralizes into ammonium in the first digestion. The nitrogen content in six real samples has been analyzed under the optimal conditions, and the nitrogen recovery rates of standard compounds added in the real samples were between 88% and 99%. The results obtained by two-step digestion–UV spectrophotometry method are consistent with those by classical Kjeldahl method (correlation coefficient is 0.9999). The possible degradation pathways of three amino acids were also proposed.  相似文献   

9.
The spatial distribution of several air pollutants emitted from iron–steel industries in Hatay-Iskenderun industrial region in Turkey was investigated by measuring their concentrations in soil. Collected soil samples (n?=?20) were analyzed for persistent organic pollutants (POPs; i.e., polycyclic aromatic hydrocarbons, polychlorinated biphenyls, polybrominated diphenyl ethers, and polychlorinated naphthalenes), anions, and trace elements. Generally, all measured POP concentrations and marker trace elements for iron–steel industry (Zn, Pb, and Cu) were high relative to those reported previously for rural and urban areas around the world, and they were comparable to those measured recently in a similar industrial region (Aliaga, Izmir, Turkey). For all investigated POPs, elements, and anions, the highest concentrations were measured at points located north of the iron–steel industries where their emissions are transported by the prevailing southerly winds. The spatial distribution and levels of POPs, elemental, and anionic concentrations indicated that the iron–steel plants in Hatay-Iskenderun region are important sources for these pollutants. Statistically significant relationships between several organic and inorganic pollutants further confirmed that they are emitted by common sources (iron–steel plants).  相似文献   

10.
This study reports distribution of uranium (U) and thorium (Th) in soil samples and the roots and shoots of some plants grown around an abandoned lead (Pb)–zinc (Zn)–copper (Cu) mining area. The plants Euphorbia macroclada, Verbascum cheiranthifolium Boiss, and Astragalus gummifer were examined. The determinations of U and Th were carried out by inductively coupled plasma‐mass spectrometry (ICP‐MS). Uranium and Th levels of the studied soil samples were found to be in the range of 1.1–70.3 mg kg?1 and 2.1–62.1 mg kg?1, respectively. Some results obtained from this study were higher than the mean U and Th concentrations of soils reported around the world. Uranium and thorium concentrations in studied plant roots were in the range of 0.04–16 and 0.08–14.57 mg kg?1, whereas in plant shoots they were 0.02–2.76 and 0.07–12.3 mg kg?1, respectively. It was concluded that the shoots of Astragalus and roots of Euphorbia and Verbascum can be used as both a biomonitor for environmental pollution and biogeochemical indicator because of their higher U and Th concentrations.  相似文献   

11.
A method for simultaneously determining the levels of aniline, benzidine, microcystin variants (microcystin-LR, RR, and YR) and carbaryl in water was developed based on ultra-performance liquid chromatography–electrospray ionization tandem mass spectrometry (UPLC-MS/MS). The chromatographic conditions were optimized for the trace determination. Without sample enrichment, the method detection limit for all test compounds ranged from 0.040 to 0.155 μg/L; meanwhile, the recoveries for all test compounds were 83.1–114%. Precision, indicated by the relative standard deviation, was <12.9%. The results meet the requirements for the determination of these compounds. Without the need to clean up the samples, the results of the analysis of samples from wastewater and surface water demonstrated that the UPLC-MS/MS method has the capability to analyze complex matrices in the trace-level monitoring of wastewater samples.  相似文献   

12.
In a study on the behaviour of pesticides in a soil–plant–water system, the quick, easy, cheap, effective, rugged and safe (QuEChERS) method for analysing pesticide or metabolite residues in soil and maize (leaves, roots and kernels) was optimized and validated. The pesticides bentazone, chloridazon and terbuthylazine and their metabolites bentazone-methyl, chloridazon-desphenyl, chloridazon-methyl-desphenyl, terbuthylazine-desethyl and terbuthylazine-2-hydroxy were selected in this study. The QuEChERS extracts obtained from soil and maize matrices and the collected leachate were analysed by liquid chromatography–electrospray ionization–tandem mass spectrometry (LC–ESI–MS/MS) using a high-performance liquid chromatography and an ultra-high-performance liquid chromatography (UHPLC) analytical column. As expected, shorter run times and higher sensitivity were achieved with the UHPLC column. Validation studies focused on recovery, repeatability, matrix effects, limits of detection and quantification. Recoveries (and repeatability relative standard deviation (RSD)) of the spiked samples were in the range of 55 to 98 % (7.4–18) in soil, 23 to 101 % (1.7–20) in maize and 82 to 105 % (4.4–25) in leachate. Quantification limits were lower than 3.0 μg kg?1 in soil, 7.3 μg kg?1 in maize and 0.080 μg l?1 in leachate.  相似文献   

13.
The study on the behaviour of potassium,phosphate and trace elements,Fe,Mn,Cu and Zn,in the rhizosphere of different varieties of flue-cured tobacco (Nicotiana tabacum L.)with high and low potassium application rate with rhizobag technique showed that soil available K,soil available P,and slow available K was in depletion status,whereas DTPA extractable Fe,Mn,Zn and Cu accumulated obviously in rhizosphere.The depletion and accumulation rates of mineral nutrients differed in degree with K application rate,soil type,and tobacco variety.The content of available K in both rhizosphere and bulk soil and K concentration in tobacco leaf increased significantly,and the available P in rhizosphere dropped with more K application.The DTPA-Fe content of red soil much lower in pH was higher than that of calcareous soil in bulk soil.But the DTPA-Fe content of calcareous soil was much higher than that of red soil in rhizosphere,which was considered perhaps to be mainly related to releasing of Fe phytosiderophore.Nitrate coule increase depletion of a vailable K in rhizosphere and also soil pH in comparision with ammonium.  相似文献   

14.
We study the effect of plant growth–promoting rhizobacteria (PGPR) along with Mesorhizobium sp. BHURC02 on nodulation, plant growth, yield, and nutrient content of chickpea (Cicer arietinum L.) under field conditions. A similar study has been conducted for nodulation and plant growth of chickpea in pot experiment under glasshouse conditions. The treatment combination of Mesorhizobium sp. BHURC02 and Pseudomonas fluorescens BHUPSB06 statistically significantly increased nodule number plant–1, dry weight of nodule plant–1, and root and shoot dry weights plant–1 over the control under a glasshouse experiment. The maximum significant increase in nodule number, dry matter, and nutrient content were recorded in co-inoculation of Mesorhizobium sp. BHURC02 and P. fluorescens BHUPSB06 followed by co-inoculation of Mesorhizobium sp., Azotobacter chroococcum, and Bacillus megatrium BHUPSB14 over uninoculated control in a 2-year field study. Hence, co-inoculation of Mesorhizobium sp. and P. fluorescens may be effective indigenous PGPR for chickpea production.  相似文献   

15.
15-day old seedlings of wheat and rape were grown in a series of solutions with different concentrations of KNO3 for a definite period of time.The changes in NO3^- concentration of the solutions were determined by the double ion-selective electrode method,and then the amount of NO3^- taken up by the plants was estimated and values of Km and Imax of the Michealis-Mentan equation were calculated.Results show that both the method and conditions of determination affected the values of Km and Imax.For example,the Km value was appreciably reduced when the volume of culture solution was increased or when the duration of nutrient uptake was shortened;the Km value obtained with short-term depletion method was higher than that obtained with long-term one.Similar Variations were found for the values of Imax.There was a considerable difference in the characteristics of uptake kinetics between wheat and rape when determined under the same conditions of determination.The isotherm of NO3^- uptake by wheat could be separated into saturated and unsaturated parts,and when the concentration of NO3^- exceeded 180μM,the relationship between the rate of NO3^- uptake and NO3^- concentration tended to be linear.However,the isotherm of NO3^- uptake by rape was found to fit the Michealis-Menten equation and no linear relationship could be found.  相似文献   

16.
This paper has investigated the ratios of closely related elements such as Mn, Cr, V, Ni, Co, Cu, Pb, Cd, Ba, Sr, La and Ce in the major soils of China, and the factors affecting them, and explored their use as indicators in soil formation, material transport and environmental pollution. Results show that the effect of soil-forming processes on the ratios of closely related elements varied with different elements, and became greater in the sequence of Ce/La <V/Cr=Ni/Co<Zn/Cu=Zn/Pb<Zn/Cd <Mn/Cr <Ba/Sr. The magnitude of the variation in the ratios of closely related elements depended on the chemical properties of the elements themselves, on the one hand, and the parent material and climatic conditions on the other.  相似文献   

17.
In the present study, a method based on dispersive liquidliquid microextraction (DLLME) followed by graphite furnace atomic absorption spectrometry (GFAAS) determination was proposed for the determination of selenium by using ammonium pyrrolidine dithiocarbamate (APDC) as the chelating reagent. The main factors influencing the DLLME were investigated systematically. Under the optimal conditions, the limit of detection for Se(IV) was 0.02 ng mL?1. The relative standard deviation was 4.1% (CSe(IV) = 0.2 ng mL?1, = 8) with an enhancement factor of 135.8-fold from only 5 mL of the water sample. The proposed method was successfully applied to the determination of Se(IV) in anodic slime and electrolyte samples. In order to validate the proposed method, a Certified Reference Material (trace elements in water, 1643e, NIST) was analyzed, and the determined value obtained was in good agreement with the certified value.  相似文献   

18.
Eurasian Soil Science - Acid–base characteristics and composition of clay minerals were estimated in the rhizospheres of Norway maple (Acer platanoides) and common spruce (Picea abies) and in...  相似文献   

19.
Eurasian Soil Science - The paper focuses on the interactions among the components of urban natural complex (surface soil layer, rhizosphere, and aboveground phytomass of herbaceous plants)...  相似文献   

20.
Adsorption and desorption of exogenous rare earth elements (REE) in soils were studied.Results showed that soils had strong adsorbability for REE and the rate of adsorption of REE was over 95% of the added REE in these tests.The characteristics of adsorption isotherms corresponded well with the both Freundlich and Temkin equations,but deviated from the Langmuir equation.The adsorption of REE tended to increase with the rising of soil pH.A sequential extraction method used for studing the desorption and distribution of REE sorbed in soils are also discussed.  相似文献   

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