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21.
Acid Mine Drainages (AMDs) from Hane? and Valea Vinului (Romania) closed mines were considered for characterization and treatment using a local zeolitic volcanic tuff, ZVT, (M?cica?, Cluj County, Romania). Water samples were collected from two locations, before and after discharging point in case of Hane? mine, and on three horizons in case of Valea Vinului mine. Physico-chemical (pH, total solid, heavy metal ions concentration) analyses showed that the environment is strongly affected by these AMD discharges even if the mines were closed years ago. Iron, manganese and zinc were the main pollutants identified in Hane? mine AMD, while zinc is the one mainly present in case of Valea Vinului AMD. A batch technique (no stirring) in which the ZVT was put in contact with the AMD sample was proposed as a passive remediation technique. ZVT successfully remove heavy metal ion from AMD. According to heavy metal ion concentrations, removal efficiencies are reaching 100%, varying as follows, Fe2+ > Zn2+ > Mn2+. When the ZVT was compared with two cationic resins (strong, SAR and weak acid, WAR) the following series was depicted, SAR > ZVT > WAR.  相似文献   
22.
Christen V  Fent K 《Chemosphere》2012,87(4):423-434
Engineered silica nanoparticles (SiO2-NPs) find widespread application and may lead to exposure of humans and the environment. Here we compare the effects of SiO2-NPs and SiO2-NPs doped with silver (SiO2-Ag-NPs) on survival and cellular function of human liver cells (Huh7) and Pimephales promelas (fathead minnow) fibroblast cells (FMH). In Huh7 cells we investigate effects on the endoplasmatic reticulum (ER), including ER stress, and interactions of nanoparticles (NPs) with metabolizing enzymes and efflux transporters. The NPs formed agglomerates/aggregates in cell culture media as revealed by SEM and TEM. SiO2 and SiO2-1% Ag-NPs were taken up into cells as demonstrated by agglomerates occurring in vesicular-like structures or freely dispersed in the cytosol. Cytotoxicity was more pronounced in Huh7 than in FMH cells, and increased with silver content in silver-doped NPs. Dissolved silver was the most significant factor for cytotoxicity. At toxic and non-cytotoxic concentrations SiO2-NPs and SiO2-1% Ag-NPs induced perturbations in the function of ER. In Huh7 cells NPs induced the unfolded protein response (UPR), or ER stress response, as demonstrated in induced expression of BiP and splicing of XBP1 mRNA, two selective markers of ER stress. Additionally, SiO2-1% Ag-NPs and AgNO3 induced reactive oxygen species. Pre-treatment of Huh7 cells with SiO2-1% Ag-NPs followed by exposure to the inducer benzo(a)pyrene caused a significant reduced induction of CYP1A activity. NPs did not alter the activity of ABC transporters. These data demonstrate for the first time that SiO2-NPs and SiO2-1% Ag-NPs result in perturbations of the ER leading to the ER stress response. This represents a novel and significant cellular signalling pathway contributing to the cytotoxicity of NPs.  相似文献   
23.
We introduce a methodology to infer zones of high potential for the habitat of a species, useful for management of biodiversity, conservation, biogeography, ecology, or sustainable use. Inference is based on a set of sites where the presence of the species has been reported. Each site is associated with covariate values, measured on discrete scales. We compute the predictive probability that the species is present at each node of a regular grid. Possible spatial bias for sites of presence is accounted for. Since the resulting posterior distribution does not have a closed form, a Markov chain Monte Carlo (MCMC) algorithm is implemented. However, we also describe an approximation to the posterior distribution, which avoids MCMC. Relevant features of the approach are that specific notions of data acquisition such as sampling intensity and detectability are accounted for, and that available a priori information regarding areas of distribution of the species is incorporated in a clear-cut way. These concepts, arising in the presence-only context, are not addressed in alternative methods. We also consider an uncertainty map, which measures the variability for the predictive probability at each node on the grid. A simulation study is carried out to test and compare our approach with other standard methods. Two case studies are also presented.  相似文献   
24.
Prions are the etiological agents of transmissible spongiform encephalopathies (TSSEs), a class of fatal neurodegenerative diseases affecting humans and other mammals. The pathogenic prion protein is a misfolded form of the host-encoded prion protein and represents the predominant, if not sole, component of the infectious agent. Environmental routes of TSE transmission areimplicated in epizootics of sheep scrapie and chronic wasting disease (CWD) of deer, elk, and moose. Soil represents a plausible environmental reservoir of scrapie and CWD agents, which can persist in the environment for years. Attachment to soil particles likely influences the persistence and infectivity of prions in the environment. Effective methods to inactivate TSE agents in soil are currently lacking, and the effects of natural degradation mechanisms on TSE infectivity are largely unknown. An improved understanding of the processes affecting the mobility, persistence, and bioaviailability of prions in soil is needed for the management of TSE-contaminated environments.  相似文献   
25.
The empirical literature reports conflicting findings on the relation between environmental policy and environmental innovation: environmental policy both encourages and impedes environmental innovation, resulting in competing theoretical explanations. To find a way out of this counterproductive debate requires new and complementary insights into the effects of different policy instruments. This research therefore advances an approach in which a set of specific policy instruments as well as firms’ behavior regarding CHP (cogeneration of heat and power) adoption are considered as two distinct factors explaining environmental innovation in the Dutch paper and board industry. Using a longitudinal research design, the focus was not on any single policy instrument but on the accumulation of policy instruments. In addition, we studied intra-organizational factors influencing the adoption decision.Overall, we can conclude that paper and board factories perceive governmental environmental policies to be relevant, but that this constitutes just one of the factors influencing adoption processes, next to intra-organizational factors. The relative importance of such policies varies over time and per adoption process. The role of top-down regulation appears to be limited, whereas interactive regulation turned out to be important for several factories in the latest period of adoption. Positive economic instruments were important in almost all adoption processes, but were not and will never be the most important reason for adoption. The most important reason for CHP adoption appears to be high energy prices in combination with cost price reduction or the threat of additional regulation. For future policies, we recommend the implementation of a specific mixture of policy instruments, attuned to the specific industry and reinforcing each other. Moreover, goals should be consistent over time to avoid risk-averse behavior.  相似文献   
26.
This paper explores policy choices made in the governance of forest resources in Lithuania during the period of 1990–2005. The present system of governance of forest resources in Lithuania is compared with a theoretical framework for good governance. In addition, the reforms in the governance model in Lithuania are placed in the context of forest governance in other countries of the region.The results of the study indicate that Lithuanian forestry has evolved from hierarchical and extreme state interventionist governance to relatively transparent and accountable governance that respects private ownership, is sensitive to the public needs and interests as well as demand and supply in the market. The results of our work have indicated that the privatization has served as the main impetus for change.On a larger scale, the reforms of the forest sector in the three Baltic States seem to have progressed in a more similar manner than compared to those in Poland, Russia, and Ukraine.  相似文献   
27.
This study outlines a new approach to the treatment of winery wastewater by application to a land FILTER (Filtration and Irrigated cropping for Land Treatment and Effluent Reuse) system. The land FILTER system was tested at a medium size rural winery crushing ~20,000 tonnes of grapes. The approach consisted of a preliminary treatment through a coarse screening and settling in treatment ponds, followed by application to the land FILTER planted to pasture. The land FILTER system efficiently dealt with variable volumes and nutrient loads in the wastewater. It was operated to minimize pollutant loads in the treated water (subsurface drainage) and provide adequate leaching to manage salt in the soil profile. The land FILTER system was effective in neutralizing the pH of the wastewater and removing nutrient pollutants to meet EPA discharge limits. However, suspended solids (SS) and biological oxygen demand (BOD) levels in the subsurface drainage waters slightly exceeded EPA limits for discharge. The high organic content in the wastewater initially caused some soil blockage and impeded drainage in the land FILTER site. This was addressed by reducing the hydraulic loading rate to allow increased soil drying between wastewater irrigations. The analysis of soil characteristics after the application of wastewater found that there was some potassium accumulation in the profile but sodium and nutrients decreased after wastewater application. Thus, the wastewater application and provision of subsurface drainage ensured adequate leaching, and so was adequate to avoid the risk of soil salinisation.  相似文献   
28.
29.
苏维埃体系解体之后,原苏维埃共和国之间森林管理的分歧变得明显.在波罗的海国家的林业部门已经发生根本变化的时候,俄罗斯却没能形成一个能适应社会-生态恢复力先决条件的制度框架.本文认为,可持续发展需要一种能够具有适应和学习能力,因而能够以实验的方式对政策不断地进行评估和再调整的制度框架.但是,这需要有参与机制,我们相信波罗的海国家在这方面正在走出一条更有希望的路子.最后,得出结论,只有建立了可持续的制度框架,社会-生态恢复力才能成为前共产主义国家自然资源管理的重要特征.  相似文献   
30.
The paper describes a model designed for analysing interrelated nitrogen (N) fluxes in farming systems. It combines the partial N balance, farm gate balance, barn balance and soil surface balance, in order to analyse all relevant N fluxes between the subsystems soil–plant–animal–environment and to reflect conclusive and consistent management systems. Such a system approach allows identifying the causes of varying N surplus and N utilisation.The REPRO model has been applied in the experimental farm Scheyern in southern Germany, which had been subdivided into an organic (org) and a conventional (con) farming system in 1992. Detailed series of long-term measuring data are available for the experimental farm, which have been used for evaluating the software for its efficiency and applicability under very different management, yet nearly equal site conditions.The organic farm is multi-structured with a legume-based crop rotation (N2 fixation: 83 kg ha−1 yr−1). The livestock density is 1.4 LSU ha−1. The farm is oriented on closed mass cycles.The conventional farm is a simple-structured cash crop system based on mineral N (N input 145 kg ha−1 yr−1). Averaging the years 1999–2002, the organic crop rotation reached, with regard to the harvested products, about 81% (6.9 Mg ha−1 yr−1) of the DM yield and about 93% (140 kg ha−1 yr−1) of the N removal of the conventional rotation. Related to the cropped area, the N surplus calculated for the organic rotation was 38 kg ha−1 yr−1 versus 44 kg ha−1 yr−1 for the conventional rotation. The N utilisation reached 0.77 (org) and 0.79 (con), respectively. The different structure of the farms favoured an enhancement of the soil organic nitrogen stock (35 kg ha−1 yr−1) in the organic crop rotation and caused a decline in the conventional system (−24 kg ha−1 yr−1). Taking account of these changes, which were substantiated by measurements, N surplus in the organic rotation decreased to 3 kg ha−1 yr−1, while it increased to 68 kg ha−1 yr−1 in the conventional system. The adjusted N utilisation value amounted to 0.98 (org) and 0.69 (con), respectively.  相似文献   
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