共查询到20条相似文献，搜索用时 15 毫秒
1.
R. Devesa-Rey R. Paradelo F. Díaz-Fierros M. T. Barral 《Water, air, and soil pollution》2008,195(1-4):189-199
The arsenic bioavailability in the bed sediments from the Anllóns River (NW Spain) has been assessed by using several analytical approaches. A six-step sequential fractionation was compared to three general availability tests: the Toxicity Characteristic Leaching Procedure (TCLP) extraction, which estimates the leaching potential of As and its effect on the survival of microorganisms (Vibrio fischeri), an extraction with 1 M HCl extraction, which estimates the bioavailability to higher plants, and a physiologically based extraction test (PBET), which estimates the bioavailability to superior animals. Arsenic was found to be mainly associated to the least mobile fractions: bound to Fe-Al oxides and in the residual phase. Among the three single extractants considered, the PBET extracted the highest As concentrations (1–11% of the total As). The TCLP extracts showed toxicity to Vibrio fischeri whereas for the plants evaluated, aqueous extracts did not show adverse effects. 相似文献
2.
Effect of 2(N‐morpholino)ethane)sulfonic acid (MES) on the growth and tissue composition of cucumber
The effect of 2(N‐morpholino)ethane)sulfonic acid (MES) on the growth of cucumber (Cucumis sativa L. var. Marketer) in hydroponic culture was determined at 0, 1, 5, and 10 mM concentrations. The effect of adding the MES to the solution at the time of transfer to hydroponic culture or waiting one week was also determined. MES was observed to strongly affect plant growth with increasing concentration in nutrient solution. Tissue and nutrient solution analysis determined that MES affects manganese (Mn) uptake. MES appears to be reduced by Mn, precipitating the Mn out of solution. The suitability of MES as a pH buffer in hydroponic culture is discussed in terms of this effect. 相似文献
3.
Data on the morphology and radiocarbon ages of humus of dark vertic quasigley nonsaline clayey soils with alternating bowl-shaped (Pellic Vertisols (Humic, Stagnic)) and diapiric (Haplic Vertisols (Stagnic, Protocalcic)) structures are discussed, and the genetic concept for these soils is suggested. The studied soils develop on loesslike medium clay in the bottom of a large closed depression on the Eisk Peninsula in the lowest western part of the Kuban–Azov Lowland. The lateral and vertical distribution of humus in the studied gilgai catena displays a lateral transition of a relatively short humus profile of the accumulative type with a maximum near the surface and with a sharp increase in 14C dates of humus in the deeper layers within the diapiric structure to the extremely deep humus profile with a maximum at the depth of 40–80 cm, with similar mean residence time of carbon within this maximum, and with a three times slower increase in 14C dates of humus down the profile within the bowl-shaped structure. The development of the gilgai soil combination is specified by the joint action of the lateral–upward squeezing of the material of the lower horizons from the nodes with an increased horizontal stress toward the zones a decreased horizontal stress, local erosional loss of soil material from the microhighs and its accumulation in the adjacent microlows, leaching of carbonates from the humus horizons in the microlows, and the vertical and lateral ascending capillary migration of the soil solutions with precipitation of calcium carbonates in the soils of microhighs. 相似文献
4.
Lago-Vanzela ES Da-Silva R Gomes E García-Romero E Hermosín-Gutiérrez I 《Journal of agricultural and food chemistry》2011,59(24):13136-13146
The aim of this study was the detailed characterization of the phenolic composition and the determination of the antioxidant activity of the Bord? grape (Vitis labrusca) cultivated in South Brazil. The edible parts of Bord? grapes (flesh and skin) contained 1130 mg/kg of total phenolic compounds (as gallic acid), mainly located in the skins. Anthocyanin content in the skins was high, largely as 3,5-diglucosides (1359 mg/kg, as malvidin 3,5-diglucoside). Total flavonols accounted for 154 μmol/kg, mainly located in the skins and with myricetin 3-glucoside as the principal flavonol in both grape parts. Very low amounts of flavan-3-ol monomers and dimers and low amounts of polymeric proanthocyanidins, with a composition similar to that reported for V. vinifera grape varieties, were found in Bord? grape skins. Hydroxycinnamic acid derivatives mainly derived from caffeic acid and were found in the skins in high amounts, ten times higher than in the flesh (total amount: 483 μmol/kg). Finally, the Bord? grape cultivar can be considered a high resveratrol producer (10.91 mg/kg) and also exhibited a high value of total antioxidant capacity (37.6 ± 1.0 mmol/kg, as Trolox). 相似文献
5.
Oliver Bajt 《Journal of Soils and Sediments》2017,17(7):1948-1960
Purpose
A medium-term study of sedimentary aliphatic hydrocarbons in the Gulf of Trieste was performed. The content of the aliphatic hydrocarbons, including their spatial and temporal distributions and origins, was determined. The collected data on the content of these compounds for the period of 2004–2013 were then processed using different evaluation indices and statistical analyses.Materials and methods
Sediment samples were collected using a gravity core sampler. Hydrocarbons were extracted with hexane and dichloromethane (1:1), and their concentrations were determined by gas chromatography (using an FID detector). Principal component analysis (PCA) was performed to establish the differences between the different sampling sites.Results and discussion
The study’s results reveal spatial and temporal variabilities in the aliphatic hydrocarbons within the investigated area. The mean concentrations of total aliphatic hydrocarbons were in the range of 17.9–84.6 μg g?1 d.w., while the concentrations of n-alkanes from C12 to C34 were 934–5232 ng g?1 d.w. The results of the analyses show higher concentrations of hydrocarbons in the coastal areas, with a decrease toward the central part of the Gulf of Trieste. The interannual differences in hydrocarbon concentrations were generally larger close to river estuaries and pollution sources, where degradation processes are more intensive. Different evaluation indices revealed the hydrocarbons to have different origins. The temporal distribution of aliphatic hydrocarbons shows a decrease in concentrations over the past few years at certain sites. Important changes in the concentration and composition of the aliphatic fraction were observed in and after 2010, characterised by intensive fluvial input and long-lasting decreased salinity.Conclusions
The content and distribution of aliphatic hydrocarbons are largely dependent on coastal sources of these compounds. Although the investigated area could be considered only slightly to moderately contaminated by hydrocarbons, the recently applied measures for pollution reduction should be continued and intensified.6.
Ioannis Massas Constantinos Ehaliotis Dionisios Kalivas Georgia Panagopoulou 《Water, air, and soil pollution》2010,212(1-4):51-63
This study reports on the concentrations, distribution, and availability of heavy metals in the children’s playground soils of Athens. Playgrounds were chosen because they are open city areas; they show relatively even spatial distribution within the district of Athens and are used by a great number of young children and their escorts on a regular basis. Samples were collected from 70 playground surface soils, representing more than 70% of the city’s playgrounds. Cu, Zn, Pb, Cr, Ni, Co, Mn, and Fe were extracted by aqua regia and by diethylene triamine pentaacetic acid (DTPA) to estimate total and available metal forms, respectively. Their mean total concentrations were 43, 174, 110, 80, 82, 22, 312, and 17?×?103?mg kg?1, respectively. The DTPA-extracted fraction showed much lower values, with means of 2.5, 7.8, 5.8, 1.5, 1.3, 0.4, 8.4, and 2.0 mg kg?1 respectively, which, however, should be carefully monitored since they relate directly to the bioavailable fraction of heavy metals. Though mean values of metal concentrations are not particularly high, the calculated enrichment factors indicate site-specific cases of high enrichment with heavy metals. Considering that the bioavailable fraction of a metal is possibly a more appropriate indicator for the recent soil pollution history, availability ratios were calculated and their distribution was visualized over the entire city profile using the appropriate GIS software. It was shown that recent metal pollution events appear to have affected mostly playground sites in the southern and eastern part of the municipality. 相似文献
7.
Ruzicka Joana Berger-Büter Karin Esslinger Nils Novak Johannes 《Genetic Resources and Crop Evolution》2021,68(7):2813-2825
Genetic Resources and Crop Evolution - Comfrey Symphytum officinale L. (true comfrey) and S.?×?uplandicum Nyman (a hybrid between S. asperum Lepech?×?S. officinale... 相似文献
8.
Yu. N. Vodyanitskii N. A. Avetov A. T. Savichev S. Ya. Trofimov E. A. Shishkonakova 《Eurasian Soil Science》2013,46(10):1032-1041
The mineral contamination of peat soils in the oil-production area differs considerably in the places of oil or stratal water spills. The time elapsed since the spill occurred is also an important factor of the changes in the chemical composition of the peat ash. The ash content rises drastically in the oil-contaminated peat, and the peat ash becomes rich in heavy metals (Mn, Ni, and Sr) and lanthanides (La and Ce). The content of K and Fe decreases, and that of P, S, Mg, Ca, Ni, and Pb increases with time at the site of old oil contamination. In the course of the self-rehabilitation of oil-contaminated peat, the content of Cl decreases more intensely than that of the heavier halogen Br. The ash content rises to a lesser extent in the peat contaminated with stratal water. The ash of the salinized peat is enriched in heavy alkaline-earth elements, i.e., Ba and Sr. Although most of the elements are leached with time, the content of Ba and Sr still remains 4–6 times higher than the background one even after long-term (more than 10 years) leaching. The concentrations of halogens rise considerably in the salinized peat, that of Cl in the peat ash decreases by 10 times, and the content of Ba virtually remains the same. 相似文献
9.
A battery of eight biomarkers was used on the freshwater bivalve Dreissena polymorpha in order to evaluate potential sub-lethal effects of the nonsteroidal anti-inflammatory drug diclofenac (DCF; 2-[(2,6-dichlorophenyl)amino]phenylacetic acid). By an in vivo approach, mussels were exposed for 96 h to increasing concentrations (0.3, 1, and 2 nM) of DCF perfectly comparable with current surface water levels. We determined the single cell gel electrophoresis assay, the apoptotic frequency (DNA Diffusion assay), the micronucleus test (MN test), and the lysosomal membrane stability (Neutral Red Retention Assay) in mussel hemocytes. Moreover, the activity of catalase, superoxide dismutase, glutathione peroxidase, and the phase II detoxifying enzyme glutathione S-transferase was measured in the cytosolic fraction extracted from a pool of entire bivalves to reveal possible alterations of the oxidative status of exposed specimens. The biomarker battery pointed out a negligible cyto- and genotoxicity on zebra mussel hemocytes since only a slight decrease of lysosomal membrane stability from baseline levels was measured at the end of exposures at the highest concentration (2 nM). In addition, environmental concentrations of DCF seem to have a negligible effect on the activities of antioxidant and detoxifying enzymes. 相似文献
10.
S. N. Lesovaya M. P. Lebedeva-Verba N. P. Chizhikova O. V. Romanov 《Eurasian Soil Science》2008,41(11):1137-1147
Soils developed from the red-brown Neogene clay and the Quaternary loesslike loams have been studied in the south of the forest-steppe zone on the Central Russian Upland. A polygenetic nature of the soil profile on the loesslike loams is shown. The modern pedogenetic processes in this soil ensure its eluvial-illuvial differentiation with the development of multilayered coatings in the illuvial horizon. The soil developed from the Neogene clay has a lower degree of differentiation despite the more acid reaction. The micromorphological study of the coatings and the mineralogical analysis of the clay fraction separated from the coatings and from the intraped mass disclose differences in the geneses of B horizons of the two soils. In the soil developed from the loesslike loam, hydromica predominates among clay minerals of the coatings; in the soil developed from the red-brown clay, smectitic minerals predominate in the clay fraction. Differences in the properties of these two parent materials predetermined differences in the major directions of soil formation: the metamorphic pedogenesis predominates on the red-brown clay, whereas the textural differentiation develops in the soil on the loesslike loam. The middle horizons in the studied soil profiles are referred to as the structural-metamorphic and textural (clay-illuvial) horizons, respectively. 相似文献
11.
Inmaculada Riba Enrique García-Luque Alejandra Maz-Courrau María Luisa González de Canales Tomás Ángel DelValls 《Water, air, and soil pollution》2010,212(1-4):329-336
This study assesses the effect of salinity in bioavailability and toxicity of Zn by means of laboratory bioassays by observing contamination in both sediment and water, accumulation of Zn in biological tissues, and histopathological damage in the gills and guts tissues of Ruditapes philippinarum clams, which were exposed to different types of sediments from the Gulf of Cádiz (SW Spain) as well as two dilutions of toxic mud coming from an accidental mining spill. With this objective, the coefficients of distribution (K D) for Zn between overlying water and sediments were calculated, the histopathological frequencies in the tissues of the gills and guts of clams were determined, and the biota-sediment bioaccumulation factors as well as the bioaccumulation factors were quantified in the different stations. Results showed that the greatest histopathological damages appeared when the salinity values decreased. Statistical results showed that salinity was inversely correlated with histopathological damage (p?<?0.01) for the lesion index for gills. The most outstanding results were observed in the two dilutions of toxic mud (0.3% and 7.9%) at a salinity value of 10. Salinity was inversely correlated with the concentration of Zn in biological tissues (p?<?0.05) and inversely correlated with the concentration of Zn in water and sediment. Zn mobilization to the overlying water is produced when salinity values decrease. 相似文献
12.
Purpose
Kutná Hora was a centre of medieval mining and remains an important contamination source in the present day. Surprisingly, very little attention has been paid to the associated contamination. Although some studies have been performed, the majority of information regarding contamination is only accessible in the archives and no overview has been published. The purpose of this study is to perform a meta-analysis of all accessible data and to shed light on this topic.Materials and methods
The data mainly come from analyses of HNO3 solutions of sediments. We used statistical analyses (exploratory data analysis, PCA). The results were visualised and evaluated in the GIS environment.Results and discussion
The complex of heavy metals As, Be, Cd, Co, Cr, Cu, Hg, Pb, V, and Zn can be divided into three main groups of different interpretation: (1) uninfluenced by mining activities—Be, Co, Cr, Hg, and V; (2) smelting processes—Cu, Pb, and Zn; and (3) mining—As and Cd. These groups also show different spatial distribution patterns, absolute concentration values and binding with different environmental types—landscape features.Conclusions
The contamination of Kutná Hora can be characterised by element grouping and also by spatial diversification. This could be used in future research as a bearer of proxy information. Surprisingly, it also seems that the spatial range of contamination of sediments could be shorter than is generally presumed.13.
14.
Eurasian Soil Science - Clay minerals are regarded as the most critical chemical and weathering components in ground. To establish the origin and distribution of the clay mineral associations of... 相似文献
15.
N. G. Minashina 《Eurasian Soil Science》2009,42(7):807-815
Experience in irrigation of chernozems in the steppe zone of Russia for a period from 1950 to 1990 is analyzed. By the end of this period and in the subsequent years, the areas under irrigation reduced considerably, and the soil productivity worsened. This was caused by the improper design of irrigation systems, on the one hand, and by the low tolerance of chernozems toward increased moistening upon irrigation, on the other hand. The analysis of the factors and regimes of soil formation under irrigation conditions shows that irrigation-induced changes in the soil hydrology also lead to changes in the soil physicochemical, biochemical, and other properties. In particular, changes in the composition of exchangeable cations lead to the development of solonetzic process. In many areas, irrigation of chernozems was accompanied by the appearance of solonetzic, vertic, saline, and eroded soils. The development of soil degradation processes is described. In general, the deterioration of irrigated chernozems was related to the absence of adequate experience in irrigation of steppe soils, unskilled personnel, improper regime of irrigation, and excessively high rates of watering. In some cases, the poor quality of irrigation water resulted in the development of soil salinization and alkalization. To improve the situation, the training of personnel is necessary; the strategy of continuous irrigation should be replaced by the strategy of supplementary irrigation in the critical periods of crop development. 相似文献
16.
《Communications in Soil Science and Plant Analysis》2012,43(6):655-664
Abstract Field trials were established on a loamy fine sand and a silt loam using snapbeans and soybeans as test crops, respectively. Row fertilizer was placed with the seed (seed‐placed). Treatments were arranged in a 3×3×3 factorial experiment, and N, P, and K were applied in all combinations at three rates (0, 3.4, and 6.8 kg/ha). Ammonium nitrate (AN), monoammonium phosphate (MAP), concentrated superphosphate (CSP) and potassium chloride (KCl) were used as sources of N, P and K. Additional treatments compared MAP with diammonium phosphate (DAP) and KCl with potassium nitrate (KNO3). The salt index of each treatment was inversely related to emergence, i.e. as the salt index increased, the emergence decreased. Level of N was more important than level of P or K in regards to reduction in emergence. Snapbeans grown on a loamy fine sand were extremely sensitive to damage from seed‐placed fertilizer, even at rates as low as 3.4 kg/ha of N, P or K. Soybeans planted on a silt loam soil were less sensitive than snapbeans planted on a loamy sand. The soybeans were able to tolerate up to 10.2 kg/ha of seed‐placed P plus K or 6.8 kg/ha of seed‐placed N plus P or N plus K without causing a significant delay in emergence. 相似文献
17.
Gosling A Stevens GW Barber AR Kentish SE Gras SL 《Journal of agricultural and food chemistry》2011,59(7):3366-3372
Prebiotic galactosyl oligosaccharides (GOS) are produced from lactose by the enzyme β-galactosidase. It is widely reported that the highest GOS levels are achieved when the initial lactose concentration is as high as possible; however, little evidence has been presented to explain this phenomenon. Using a system composed of the commercial β-galactosidase derived from Bacillus circulans known as Biolacta FN5, lactose and sucrose, the relative contribution of water activity, and substrate availability were assessed. Oligosaccharide levels did not appear to be affected by changes in water activity between 1.0 and 0.77 at a constant lactose concentration. The maximum oligosaccharide concentration increased at higher initial concentrations of lactose and sucrose, while initial reaction rates for transfer increased but remained constant for hydrolysis. This suggests that the high oligosaccharide levels achieved at the raised initial saccharide concentration are due to increases in reactions that form oligosaccharides rather than decreases in concurrent reactions, which degrade oligosaccharides. There were different effects from changing the initial concentration of lactose compared to sucrose, suggesting that the ability of lactose to act as a donor saccharide may be more important for increasing maximum oligosaccharide concentrations than the combined ability of both saccharides to act as galactosyl acceptors. 相似文献
18.
Kogut B. M. Artemyeva Z. S. Kirillova N. P. Yashin M. A. Soshnikova E. I. 《Eurasian Soil Science》2019,52(2):141-149
Eurasian Soil Science - The content and the composition of soil structural units of different hierarchical levels were studied for Haplic Chernozems (Loamic, Pachic) of Kursk region under... 相似文献
19.
Masanori Mitsuchi 《Soil Science and Plant Nutrition》2013,59(4):141-146
On the high terrace to the north of Akashi City, Sanyo District. th ere is a heavy text ured soil which is charac te rized by the presence of altern ate red and gray bands in lower hor izons (photo.) . This soil is called "Tora-han" Soil as a local name by reason of its morph ological resemblance to “tora” (tiger*). Heavy textured soils which have tiger-like (or zebra-like) mot tlings in lower hor izons are also found in other parts of Japan alm ost excl usively on high ter races , and hav e long attracted th e attent ion of Japanese pedologists. 相似文献
20.