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321.
This work investigates the ecotoxicological evaluation of contaminated dredged sediments from French Mediterranean navy harbour (A), commercial port (B) and two composite specimens (C) and (D) coming from the mixture of A and B with other port sediments. The toxicity of elutriates from these sediments is estimated using embryo-toxicity test, Microtox® solid phase test, LuminoTox, phytotoxicity tests and genotoxicity test. Bioassay responses are not clearly correlated with chemical contamination in the whole sediment and vary as a function of tested organisms. The highest contaminated samples (A and C) are almost always more toxic than the less contaminated samples (B and D). Among composite sediments, the mixture effect with other sediments is not efficient to decrease toxicity in sample C, suggesting that other parameters influence toxicity level such as particle size or organic matter content. These parameters should be taken into consideration in order to improve the efficiency of the mixture process and produce composite sediments with low toxicity.  相似文献   
322.
323.
Here we present the methodology used for terrestrial biodiversity analysis and site selection in Phase B of the UNDP/GEF COAST project. The analysis was focused on the problem of biodiversity evaluation in four Croatian counties stretching from sea level to the highest mountain in Croatia. Data on habitats, vascular flora, and fauna (mammals, birds, reptiles, amphibians, butterflies, ground beetles, and underground invertebrates) were collected and analyzed for each of the four counties. Emphasis was given to the richness of endangered species and the rarity of endemic species. Based on the spatial analyses of habitat, fauna, and flora data, four to six areas were selected from each county and ranked according to their biodiversity importance. Overlap between areas important for richness and those important for rarity was highest for data on flora (65.5%) and lowest for data on fauna (16.7%). When different data sets were compared, the lowest overlap was between flora and fauna (17.1%) and largest between fauna and habitats (23.9%). Simultaneous overlap among all three data sets was found in just 6.5% of the overall selected areas. These results suggest that less specific data, with respect to taxa threat status, could better serve as surrogate data in estimating overall biodiversity. In summary, this analysis has demonstrated that Dalmatia is a region with a high overall biodiversity that is important in a broader European context.  相似文献   
324.
This work focused on anaerobic biodegradation of blends composed of glycerol-plasticized polyvinyl alcohol (PVA) and biopolymer (starch, gellan, xanthan) in an aqueous environment, after inoculation with digested activated sludge from a municipal wastewater treatment plant. Glycerol degradability is comparable to degradability of used modifying agents. Modifying agents added in the 20–40 wt% range proportionally increased biodegradation degree (Dt) calculated from balance of transformed carbon in the system. Biodegradation degree of polysaccharides and glycerol attained 95% and over. For PVA it was only 6.5% (in breakdown times up to 500 h). Content of polysaccharides favorably affects biodegradation degree of polyvinyl alcohol blends, but at the expense of reduced mechanical properties of resultant products.  相似文献   
325.
This study investigated the sorption characteristics and recovery of selected heavy metal Cd(II) from K-feldspar and sepiolite, representative soil components, using rhamnolipid biosurfactant. Although the proposed technique was classified as a soil bioremediation process, it can also be applied to treatment of waste waters containing Cd(II) ions with minor modifications. The effect of initial Cd(II) concentration on sorption capacity was characterized by determining the sorption isotherms. Of the four models examined, the Freundlich model showed the best fit for the sorption of Cd(II) on K-feldspar, whereas the Langmuir-model was used successfully to characterize the sorption of Cd(II) on sepiolite. Although a high Cd(II) uptake of 7.49 mmol/kg by K-feldspar was obtained, sepiolite was a superior Cd(II) accumulater, with a maximum Cd(II) uptake of 24.66 mmol Cd(II)/kg. The presence of Cd(II) in the sepiolite or K-feldspar prior to addition of the rhamnolipid generally resulted in less rhamnolipid sorption to sepiolite or K-feldspar. The maximum Cd(II) desorption efficiency by rhamnolipid from K-feldspar was substantially higher than that of sepiolite and determined to be 96% of the sorbed Cd(II), whereas only 10.1% of the sorbed Cd(II) from sepiolite was recovered by rhamnolipid solution.  相似文献   
326.
Cukrov N  Cmuk P  Mlakar M  Omanović D 《Chemosphere》2008,72(10):1559-1566
The spatial distribution of dissolved and total trace metals (Zn, Cd, Pb and Cu) in the Krka River (partly located in the Krka National Park) has been studied using a "clean" sampling, handling and analysis technique. Differential pulse anodic stripping voltammetry (DPASV) with a hanging mercury drop electrode (HMDE) has been used for trace metal analysis. The Krka River has been divided into the upper and lower flow region with respect to the metals concentration and main physico-chemical parameters. A significant increase in trace metal concentration as the result of the untreated waste water discharge downstream of Knin Town has been registered in the upper flow region. Due to a specific characteristic of the Krka, the so-called self-purification process, a decrease in the elevated trace metals concentration from the water column takes place at numerous small lakes formed by tufa barriers (at the end of the upper flow region). The clean groundwater input at the beginning of the lower flow region additionally contributes to the observed decrease in trace metals concentration in the Krka, maintaining them at a very low level in the remaining region of fresh-water flow. The determined median total concentrations were zinc 120-7400 ng l(-1), cadmium 3-8 ng l(-1), lead 11-250 ng l(-1) and copper 110-440 ng l(-1). Karst rivers, such as the Krka River, with extremely low natural concentrations of trace metals are highly sensitive to the anthropogenic influence. Therefore, such aquatic systems require implementation of strict protection regimes in the entire catchments area.  相似文献   
327.
In order to study the influence of microorganisms on the mercury biogeochemistry, the metal content and the structure of microbial communities were determined in sediments from stations along the Adour Estuary. The comparison of the bacterial communities and their distribution in function of the environmental parameters by Canonical Correspondence Analysis (CCA) revealed the influence of metals on the bacterial communities structure. Sediments where the bacterial communities are mostly influenced by methylmercury were incubated in slurries with or without mercury, under oxic and anoxic conditions. Methylmercury production was detected in the anoxic biotic slurries with a net methylation yield of 0.3% after 24 h. CCA based on T-RFLP profiles revealed the impact of mercury addition on the bacterial communities structure. In addition, 17 bacterial strains, mainly sulphate-reducing bacteria involved in mercury methylation, were isolated and identified.  相似文献   
328.
This paper explains briefly the conceptual framework of an ecosystem-based multiple-use forest management planning focusing on biodiversity conservation and participation. Some results from a case study were documented to realize the implementation of the concept. A strong liaison between the related institutions and major stakeholders and the effective use of Geographic Information System (GIS) and Remote Sensing (RS) are necessary. Effective participation is evident only with the involvement of enthusiastic and skillful stakeholders. A case study of ??neada, Turkey, supported the idea that participation as communication has better possibilities to promote multiple-use forest management than participation as information gathering. Primary challenges relate to the effectiveness of conservation program, availability of coherent biodiversity data, capacity building; awareness, training, and common understanding of biodiversity and protected area concept; coordination among the related institutions and stakeholders; and willingness and enthusiasm of authorities to accept and implement the concept.  相似文献   
329.
Changes in photosynthetic and antioxidant activities in maize (Zea mays L.) leaves of cultivars 3223 and 31G98 exposed to excess copper (Cu) were investigated. Cu treatment reduced the shoot and root length of both cultivars. No significant difference of Cu accumulation in the roots of both cultivars was observed while the cultivar 3223 accumulated significantly higher Cu in leaves than 31G98. The observed decreases in effective quantum efficiency of PSII, ETR and qP indicate an over excitation of photochemical system in 3223 compared to 31G98. The leaf chlorophyll and carotenoid contents of both cultivars decreased with increasing Cu concentration. A far higher production of anthocyanins in 31G98 has been observed than that of 3223. At 1.5 mM Cu concentration, all antioxidant enzyme activities increased in leaves of the cultivar 31G98 while there were no significant changes in SOD and GR activities in 3223 compared to the control except increased APX and POD activities. The lower Cu accumulation in leaves and higher antioxidant enzyme activities in 31G98 suggested an enhanced tolerance capacity of this cultivar to protect the plant from oxidative damage.  相似文献   
330.
Two country-wide surveys using epiphytic lichens as biomonitors of atmospheric pollution carried out during 2000 and 2001 in Slovenia were compared with surveys in 1991 and 1992. In the first survey, epiphytic lichen cover was studied in more than 500 plots of the 4 x 4 km national grid carried out within the framework of forest decline inventories. In the second survey, the epiphytic lichen Hypogymnia physodes (L.) Nyl., was collected on a 16 x 16 km bioindication grid and analysed for S, N, As, Br, Ce, Cd, Cr, K, La, Mo, Rb, Sb, Th, U and Zn contents. Only 'forested area' sampling points were included in the present study. Lichen cover was low, with about 70% of plots with less than 10% foliose lichen cover. No relationship was found between Hypogymnia trace element, N and S concentrations and foliose epiphytic lichen cover.  相似文献   
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