Lead (Pb) in Arctic Char (Salvelinus alpinus) from Oligotrophic Alpine Lakes: Gills versus Digestive Tract

We studied Arctic char (Salvelinus alpinus) from two oligotropic high mountain lakes in Northern Tyrol, Austria, that differed in pH (5.4 and 7.1) and alkalinity (1.3 and 100.3 µeq L^-1). Concentrations of Pb in gills, liver, kidney, gut and contents of stomach and gut were investigated during winter and summer to elucidate pathways for Pb uptake in these fish. Our study illustrates ratios of Pb concentrations of gills to stomach or gills to intestine (G/S and G/l ratios) to be a valuable tool for evaluating the relative contributions of different pathways of metal uptake in fish. In both sampling periods (winter, summer) the gills appear to represent a major route pf Pb uptake in fish from low alkalinity lakes. However, during the ice-covered period the diet becomes an increasingly important additional source of Pb contamination.     

The Role of Iron Bacteria on Weathering and Attenuation Processes at Acidic Environments

The present research reproduces the chemical and microbiological reactions that occur naturally when a metal sulfide is discharged onto a natural soil, with special emphasis on iron cycle. The role of indigenous microbiota from an extremely acidic site on both weathering and attenuation processes related to the iron mobilization has been studied and the iron cycle has been reproduced at laboratory scale. In the first stage, the weathering phase, a residual sulfide mineral was bioleached using a mixed culture of iron-oxidizing bacteria isolated from the own substrate. The acid liquor obtained (pH 2), with a high metal concentration (160 mM in total iron), was filtered and neutralized. Solids obtained from the two sources (from the weathering process and after the neutralization stage) were characterized by X-ray and scanning electron microscope/energy dispersive X-ray spectroscopy, resulting ferric iron precipitates such as jarosites, goethites, and ferrihydrites with different crystalline properties. The contribution of ferric iron-reducing bacteria on the attenuation of high-content iron effluents was also studied. Mixed cultures of ferric iron-reducing bacteria, isolated from those acidic substrates, were active in reducing soluble ferric iron (60 mM in concentration), and a 66% of bioreduction was reached after 15 days. Dissimilatory ferric iron reduction has been achieved with adapted cultures at pH values from 7 to 4.     

Sex pheromone in Tetrodontophora bielanesis (Waga, 1842) (Collembola: Onychiuridae): Indirect reproduction mediated by cuticular compounds

An olfactory sexual recognition signal was investigated in Tetrodontophora bielanensis (Collembola: Onychiuridae). A preliminary olfactometry experiment showed an unequivocal attraction of males by the odor of females. This led us to conduct male attraction tests using polar and apolar fractions of female cuticular extract. The polar fraction of the extract was shown to contain the component that plays an active role in sexual attraction in this Collembola species. The results of the present study are the first to show a direct relationship between an olfactory signal and sexual attraction in Collembola.     

多环芳烃长期污染土壤的微生物强化修复初步研究

本研究通过室内模拟试验,以急性毒性较强的菲(Phe)和遗传毒性较强的苯并[a]芘(B[a]P)为代表性多环芳烃(PAHs)污染物,以不同C源、通气状况和水分条件为调控因子,对PAHs长期污染土壤的土著微生物强化修复进行初步研究。结果表明,搅动处理使污染土壤中Phe和B[a]P的降解率分别达59.44%和26.14%,而淹水处理使两者降解率分别达46.48%和13.27%。添加C源(淀粉和葡萄糖)处理提高了土壤中PAHs的降解率,且随着C源的施用量而增加。同时也发现污染土壤中PAHs降解菌和微生物总量呈正相关,并随着PAHs降解菌数量的增加,土壤中PAHs降解率也随之提高。可见,土壤中PAHs降解速率主要决定于PAHs的降解菌数量。     

生物质炭修复有机物污染土壤的研究进展

生物质炭由于其特殊的多孔性结构、强的吸附性能,以及富含多种营养元素和特殊官能团等特点,成为近年来在农业应用和环境污染治理方面的热点。本文介绍了生物质炭的基本特性,提出生物质炭可能在今后成为活性炭的替代品;综述了生物质炭在修复有机物(石油烃、有机农药、PAHs、PCBs)污染土壤中的研究进展,并探讨了生物质炭应用于污染土壤修复的环境风险。生物质炭在修复有机物污染土壤方面有巨大的潜力,但在大规模应用之前还需要做长期深入的研究。     

Role of Humic Substances on Cr(VI) Removal from Groundwater with Pyrite

Groundwater composition may have a pronounced impact on long-term performance of permeable reactive barriers (PRBs). Here, batch and column experiments were conducted to investigate the effects of humic acid (HA) on Cr(VI) removal by pyrite in systems containing cations such as Ca²⁺ and Mg²⁺. HA was observed to have inhibitory effect on Cr(VI) uptake by pyrite under the experimental conditions studied (e.g., pH 3 to 8). HA sorbed onto pyrite surface and thus (1) competed against Cr(VI) for pyritic surface sites and/or (2) increased electrostatic repulsion between Cr(VI) and pyrite. In systems with HA and Ca²⁺/Mg²⁺, the Cr(VI) uptake by pyrite decreased drastically relative to HA alone due to the aggregation of HA with Ca²⁺/Mg²⁺. The formation of such HA aggregates/precipitates blocked Cr(VI) ions to reach its binding sites, thereby resulting in a substantial decrease in Cr(VI) uptake. Overall, the results have major implications for proper design and operation of PRBs with pyrite as the reactive material.     

Role of carbonyl compounds in SO(2) binding phenomena in musts and wines from botrytized grapes

Carbonyl compounds play an important role in musts from botrytized grapes. Some of them, such as glyoxal and methylglyoxal, may explain a considerable part of bindable SO(2). Others, such as 2- and 5-oxogluconic acids, produced by gluconic acid oxidation in proportions respectively from 2.5 per 1 play an interesting role as SO(2) binding indicator. Finally, the levels of some compounds such as dihydroxyacetone, 5-oxofructose, and delta-gluconolactone in balance with gluconic acid are well correlated with SO(2) binding powers and also explain a large part of the bindable SO(2) in musts. During alcoholic fermentation, only dihydroxyacetone among these three compounds is metabolized by yeast. Thus, two compounds present in grapes, delta-gluconolactone and 5-oxofructose, with three yeast SO(2)-binding byproducts, ethanal, pyruvic, and 2-oxoglutaric acids, explain much of the SO(2) binding power in wines from botrytized grapes.     

Characterization and Sources of PAHs and Potentially Toxic Metals in Urban Environments of Sevilla (Southern Spain)

The purpose of this study was to determine the degree of PAH contamination and the association of PAHs with metals in urban soil samples from Sevilla (Spain). Fifteen polycyclic aromatic hydrocarbons-PAHs (naphthalene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, dibenzo[a,h]anthracene, benzo[g,h,i]perylene, indeno[1,2,3-c,d]pyrene) and seven metals (Cd, Cr, Cu, Mn, Ni, Pb, Zn) have been evaluated in representative urban soil samples. Forty-one top soils (0–10 cm) under different land use (garden, roadside, riverbank and agricultural allotment) were selected. PAHs from soil samples were extracted by sonication using dichloromethane. The simultaneous quantification of 15 different PAH compounds were carried out by HPLC using multiple wavelength shift in the fluorescence detector. For qualitative analysis a photo diode-array detector was used. Metal (pseudo-total) analysis was carried out by digestion of the soils with aqua regia in microwave oven. The mean concentration of each PAH in urban soils of Sevilla showed a wide range, they are not considered highly contaminated. The results of the sum of 15 PAHs in Sevilla soils are in the range 89.5–4004.2 μg kg^?1, but there seems not to be a correlation between the concentration of PAHs and the land use. Of the 15 PAHs examined, phenanthrene, fluoranthene and pyrene were present at the highest concentrations, being the sum of these PAHs about 40% of the total content. Although metal content were not especially high in most soils, there are significant hints of moderate pollution in some particular spots. Such spots are mainly related with some gardens within the historic quarters of the city. The associations among metals and PAHs content in the soil samples was checked by principal components analysis (PCA). The largest values both for ‘urban’ metals (Pb, Cu and Zn) and for PAHs were mainly found in sites close to the historic quarters of the city in which a heavy traffic of motor vehicles is suffered from years.     

Performance of Common Bean (Phaseolus vulgaris L.) Landraces from Spain in the Atlantic and Mediterranean Environments

Ninety-five common bean (Phaseolus vulgaris L.) landraces from Spain were evaluated in three different environments in northern Spain for their agronomic performance and seed quality. Significant differences among landraces were found for 14 quantitative traits related to phenology, yield and its components, and seed quality traits. Environmental effects were significant for all traits evaluated except for seeds pod^?1, seed width/thickness, seed weight, and seed water absorption. Landrace by environment interactions were significant for all traits except for seeds pod^?1 and seed water absorption. Selection of new breeding lines for agronomic performance and seed quality within landraces should be reliable because many of them are mixture of lines. Some heirloom varieties belonging to the types faba, caparrón,riñón,ganxet and tolosana had the best performances regarding to seed quality and yield. Principal component analysis revealed differences among environments affecting the performance of the bean landraces. Variation in the landraces seems to be organized in a different way in each one of the test environments, therefore, low plasticity and specific adaptation of Spanish bean landraces to different environments is derived from this study. Some landraces, especially those large and white seeded should be an useful resource for sustainable farming systems in different biogeographical areas and a worthy germplasm for the genetic improvement of agronomic value and seed quality.     

石油污染土壤中细菌的分离筛选

从辽河油田石油污染土壤中分离筛选得到59株细菌,并对其石油降解能力进行了研究。结果表明,大多数细菌具有较高的石油降解能力及脂酶活性,其中B-4、B-5、B-46、B-47四株细菌的石油降解率分别达到52.1%、55.4%、51.6%、59.3%。经初步鉴定B-5、B-46、B-47均属于微球菌属(Micrococcusspp.),B-4属于节杆菌属(Arthrobactersp.)。     

Assessment of Highly Polluted Fluvisol in the Spittelwasser Floodplain Based on National Guideline Values and MNA-Criteria (11 pages)

Background, Goal and Scope

Nearly all large European rivers have been used as disposal pathways for several unwanted substances. Deposition of the contaminated solids occurs in regions of slack water and also during floods in adjacent floodplains. As a result of the recurrent input, most of the floodplains in central Europe are contaminated by manifold inorganic and organic pollutants, representing a risk for both plants and groundwater at the site, and for areas downstream. The aim of the present paper is to demonstrate and assess the sink and source functions of a highly contaminated 'fluvisol' (= alluvial soil) for inorganic and persistent organic pollutants. The extent of contamination is described on the basis of national guidelines. These results are further discussed on the basis of the 'monitored natural attenuation' (MNA) potential, i.e., with respect to the requirements for the cheapest problem solution for large scale contamination of floodplains. The MNA potential is assessed according to several lines of evidence such as contaminant burial, mechanical and chemical mobility, transformation to less toxic forms, and dilution due to dispersion.

Methods

The existing inorganic and organic pollutant status and the ecotoxicological potential of the Spittelwasser floodplain near Jeßnitz was documented by analysing several element and compound depth profiles of a typical alluvial soil site. Geochemical analyses were performed on solid material and soil solution according to standard procedures. In laboratory experiments monoliths were continuously irrigated with deionised water and the leachate was analysed weekly. In addition to the geochemical, the ecotoxicological status of the samples was studied using different biotests for the dissolved and the solid phase.

Results

The measured alluvial soil profile is severely contaminated with numerous inorganic and organic pollutants. Highest enrichment factors according to the catchment based, element specific geological background were found for Hg (402), Pb (8.9), Cr (7.1) and Cd (6.3). Assessment was made of the hazard potential of both the solid material and the soil solution according to the German Federal Soil Protection and Contaminated Sites Ordinance (BBodSchV). Relating to the respective maximum contents in the soil profile, the overstepping of BBodSchV trigger values is highest for Hg with a coefficient of 49.0 followed by Cd (14.3), Pb (12.2), Zn (7.3), Cr (5.9) and Cu (3.6). Pollutant concentrations in the soil solution exceed the threshold values for Cd, Cu and Zn by factors of 6.3 to 12. While DDT is retained in the topsoil, there is a considerable translocation of HCH towards deeper horizons.

Discussion

The algae test confirms a strong toxicity in the top layer of the soil profile. In contrast, no such toxic reactions were indicated by the luminescent bacteria test and the Daphnia test at this depth. However, the deeper layers (10 - 100 cm) show a toxic reaction by the Daphnia test, thus indicating a relevant translocation of contaminants.

Conclusions and Perspectives

The Spittelwasser floodplain represents a significant sink for inorganic and persistent organic pollutants. Simultaneously, the area is a relevant secondary source of dissolving contaminants like heavy metals and HCH. Although strict criteria in the lines of evidence for applying MNA are not fulfilled, it can be stated that the alluvial soil offers a high natural retention potential for As, Hg, DDT, and PCDD/F. These pollutants are firmly retained and are not found in the soil leachate. This meets the demands of the EC-WFD for pollutant retention close to their primary source. But for agricultural use and groundwater recharge the natural attenuation potential of the soils in the Spittelwasser area will not be sufficient to achieve acceptable conditions medium-term. The main problem for the dissemination of pollutants is not chemical stability but mechanical dispersion. This is particularly the case for PCDD/F, with concentrations of more than 10,000 ng/kg I-TEQ in the upper Spittelwasser soil layers. Dispersion processes can result in a wide spatial contamination of downstream floodplains.     

淀粉对无芒雀麦修复煤矿区多环芳烃长期污染土壤的影响

采用温室盆栽试验,以无芒雀麦(W)为修复植物,研究淀粉(D)不同剂量与无芒雀麦组合对煤矿区多环芳烃(PAHs)长期污染农田土壤修复的影响。结果表明,在土壤中添加淀粉剂量D1、D2培养3个月后,显著促进了土著微生物对煤矿区长期污染农田土壤PAHs的降解。D1、D2处理土壤中16种PAHs总量降解率(16.82%,19.06%)分别比对照CK(11.12%)提高了51.26%和71.40%,尤其对6环PAHs的降解增效最为突出。D2处理对6环PAHs的降解达最高,为37.05%,比CK处理提高了241.01%,且为D1处理的1.77倍。在污染土壤中添加淀粉并种植无芒雀麦(D1+W,D2+W)后,与对照CK、淀粉(D)和种植无芒雀麦单一处理(W)相比,土壤中16种PAHs总量降解率有了明显增加,D1+W与D2+W处理下16种PAHs降解率分别为26.26%和28.39%;在PAHs不同环数中对5,6环PAHs的修复效果提升最为明显,对其它环数PAHs降解效果提升不显著,其中5环和6环PAHs降解率在D2+W组合处理下达到最高,为48.63%和58.32%,比CK处理提高了110.36%和436.82%,比无芒雀麦单一处理提高了27.50%和47.77%。从土壤酶活性角度,淀粉、无芒雀麦单一处理及其组合下的土壤过氧化氢酶活性差异不明显,但均显著高于对照CK处理;无芒雀麦对多酚氧化酶活性有明显的激活作用,且与淀粉组合进一步显著提升了该酶的活性,与D1+W与D2+W组合下的5,6环PAHs降解率达最高相一致。综上,利用淀粉与无芒雀麦的优化组合形式能明显提升煤矿区5,6环PAHs长期污染农田土壤的修复效果,可以作为该区污染土壤修复治理的一种选择。     

纳米羟基磷灰石对铅污染土壤中小白菜铅吸收特性和生理生化特征的影响

通过盆栽试验探讨施用纳米羟基磷灰石(NHAP)对铅污染土壤中小白菜生长及品质的影响。研究表明,施用NHAP能有效提高铅污染土壤中小白菜的生物量,并能减少小白菜地上部和地下部对铅的吸收。施用NHAP还能缓解铅对小白菜的胁迫作用,表现为叶片叶绿素含量和维生素C含量升高,丙二醛(MDA)含量下降;NHAP还能增加小白菜抗氧化酶含量水平,提高过氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)的含量,提高小白菜清除活性氧的水平,抑制脂质过氧化作用,从而保护细胞膜的结构,维护其正常的生理生化功能。结果表明,施用纳米羟基磷灰石能有效促进铅污染土壤中小白菜的生长,并且提高其品质,这对于改善铅污染土壤质量,提高小白菜产量及品质具有很好的作用。     

Immobilization of Zn and Pb in Polluted Soil by In Situ Crystallization Zeolites from Fly Ash

In the last few years, a great deal of research on soil has been carried out in order to develop a low-cost remediation method for reducing the environmental risks due to the pollution caused by heavy metals. In the light of this, the zeolitization achieved in soils mixed with coal fly ash could be a useful answer to reduce the amount and the mobility of metals in polluted areas. In this study, a selected soil treated with coal fly ash and artificially contaminated with Zn or Pb was used to synthesize zeolite at low temperature in laboratory and on a bench-scale experiments. Mineralogical data showed that the synthesis of zeolite X took place readily after the first month, and the amount of the newly formed mineral increased during the entire 1-year-long incubation period. The presence of toxic elements does not interfere with zeolite crystallization, whereas the chemical analysis indicated that a reduction in heavy metal availability takes place in the samples characterized by the presence of zeolite.     

图书馆从自动化向数字化跨越过程中馆员角色的变化

通过对图书馆从自动化时期向数字化时期跨越过程中图书馆各个部门职能的变化,探讨了图书馆员的角色变化,并对来自出版商竞争的影响进行了分析。     

Effectiveness of Natural Compounds on DNA Damage in <Emphasis Type="Italic">Coris julis</Emphasis> (Linneaus 1758) from a Polluted Marine Area

The evaluation of DNA damage in aquatic organisms represents one of the most widely used biomarkers in the assessment and monitoring of marine pollution. Our previous research highlighted the presence of DNA damage in hepatic nuclei and blood cells of Coris julis specimens collected from Augusta harbor (Syracuse, Italy), a site highly polluted. In this work, we investigated on the ability of different natural compounds with antioxidant and immunostimulating properties, such as resveratrol (50 μM, 100 μM), amygdalin (100 μM, 200 μM), and Urtica dioica roots extract (50 and/or 100 μg/ml), in reducing DNA damage of C. julis. Blood cells were analyzed by atypical cellular comet assay. The results confirmed that Augusta specimens are the most damaged and showed that resveratrol, followed by amygdalin and U. dioica roots extract, drastically reduced DNA damage. This finding evidences the effectiveness of three natural compounds for DNA protection suggesting the possible use of feed enriched with antioxidant compounds in aquaculture practices for organisms damaged by natural and anthropic insults.     

Role of dissolved organic nitrogen (DON) in soil N cycling in grassland soils

Dissolved organic nitrogen (DON) represents a significant pool of soluble N in many soils and freshwaters. Further, the low molecular weight (LMW) component of DON represents an important source of N for microorganisms and can also be utilized directly by some plants. Our purpose was to determine which of the pathways in the decomposition and subsequent ammonification and nitrification of organic N represented a significant block in soil N supply in three agricultural grassland soils. The results indicate that the conversion of insoluble organic N to LMW-DON and not LMW-DON to NH₄⁺ or NH₄⁺ to NO₃⁻ represents a major constraint to N supply. We hypothesize that there are two distinct DON pools in soil. The first pool comprises mainly free amino acids and proteins and is turned over very rapidly by the microbial community, so it does not accumulate in soil. The second pool is a high molecular weight pool rich in humic substances, which turns over slowly and represents the major DON loss to freshwaters. The results also suggest that in NO₃⁻ rich soils the uptake of LMW-DON by soil microorganisms may primarily provide them with C to fuel respiration, rather than to satisfy their internal N demand.     

Quantitative Variation of HMW Glutenin Subunits from Hard Red Spring Wheats Grown in Different Environments

The objective of this study was to investigate the quantitative variation of HMW glutenin subunits in relation to glutenin polymers and hence breadmaking quality across different environments. Six genotypes of hard red spring (HRS) wheat were grown at seven locations in North Dakota in 1998 in a randomized complete‐block experimental design with three replicates at each location. Unreduced SDS‐soluble glutenins of flour were fractionated by multistacking SDS‐PAGE into different sized glutenin polymers, followed by SDS‐PAGE and imaging densitometry to determine the quantitative variation of HMW glutenin subunits. SDS‐insoluble glutenin polymers also were examined for their quantitative composition of HMW glutenin subunits. The results showed that the percentage of HMW glutenin subunits was significantly affected by growing locations. The quantity of HMW glutenin subunits in SDS‐insoluble glutenins was significantly and positively correlated with loaf volume. SDS‐insoluble glutenin polymers had a higher percentage of HMW glutenin subunits than did SDS‐soluble glutenins. SDS‐insoluble glutenin polymers in flour were positively and significantly correlated in proportions of both total and individual HMW glutenin subunits in total SDS glutenins. SDS‐insoluble glutenin polymers also were positively and significantly correlated with the combined proportion of HMW glutenin subunits 2* + 5. The results of this study indicated that either subunit 2* or 5 might be more important in forming a greater quantity of larger SDS‐insoluble glutenin polymers than other subunits. SDS‐insoluble glutenin polymers from different cultivars or locations could have different quantities of HMW glutenin subunits in their composition. SDS‐insoluble glutenin polymers with more HMW glutenin subunits might be larger sized than those with less HMW glutenin subunits. Environment significantly influenced the quantitative variation of HMW glutenin subunits, which in turn affected the size distribution of glutenin polymers, and hence breadmaking quality.