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121.
Kauppi S Romantschuk M Strömmer R Sinkkonen A 《Environmental science and pollution research international》2012,19(1):53-63
Purpose
Prevalence of organic pollutants or their natural analogs in soil is often assumed to lead to adaptation in the bacterial community, which results in enhanced bioremediation if the soil is later contaminated. In this study, the effects of soil type and contamination history on diesel oil degradation and bacterial adaptation were studied. 相似文献122.
Community-based collaborative groups involved in public natural resource management are assuming greater roles in planning,
project implementation, and monitoring. This entails the capacity of collaborative groups to develop and sustain new organizational
structures, processes, and strategies, yet there is a lack of understanding what constitutes collaborative capacity. In this
paper, we present a framework for assessing collaborative capacities associated with community-based public forest management
in the US. The framework is inductively derived from case study research and observations of 30 federal forest-related collaborative
efforts. Categories were cross-referenced with literature on collaboration across a variety of contexts. The framework focuses
on six arenas of collaborative action: (1) organizing, (2) learning, (3) deciding, (4) acting, (5) evaluating, and (6) legitimizing.
Within each arena are capacities expressed through three levels of social agency: individuals, the collaborative group itself,
and participating or external organizations. The framework provides a language and set of organizing principles for understanding
and assessing collaborative capacity in the context of community-based public forest management. The framework allows groups
to assess what capacities they already have and what more is needed. It also provides a way for organizations supporting collaboratives
to target investments in building and sustaining their collaborative capacities. The framework can be used by researchers
as a set of independent variables against which to measure collaborative outcomes across a large population of collaborative
efforts. 相似文献
123.
In many regions of the world, fires are primarily of anthropogenic origin. In northwestern Patagonia, the number of fires
is not correlated with meteorological variables, but is concentrated in urban areas. This study was conducted in the wildland–urban
interface (WUI) area of San Carlos de Bariloche (Patagonia, Argentina), within the Nahuel Huapi National Park. WUI fires are
particularly problematic because, besides people and goods, they represent a danger to protected areas. We studied the relationship
between fire records and socioeconomic indicators within the WUI of San Carlos de Bariloche. We conducted a Multiple Correspondence
Factorial Analysis and an Ascendant Hierarchical Classification of the city neighborhoods. The results show that the neighborhoods
in Bariloche can be divided into three classes: High Socioeconomic Fire Risk neighborhoods, including neighborhoods with the
highest fire rates, where people have low instruction level, high levels of unsatisfied basic needs and high unemployment
levels; Low Socioeconomic Fire Risk neighborhoods, that groups neighborhoods which present the opposite characterization,
and Moderate Socioeconomic Fire Risk neighborhoods, which are more heterogeneous. Once neighborhoods were classified, a Socioeconomic
Fire Risk map was generated, supplementing the existing WUI Fire Danger map. Our results emphasize the relevance of socioeconomic
variables to fire policies. 相似文献
124.
The concentrations of heavy metals and metals (Zn, Pb, Bi, Cd, Ni, Co, Fe, Mn, Mg, Cu, Cr, Ca, Sr, Na, Li, K) were measured in muscle of five species Cyprinus carpio (from I??kl? dam), Scardinius erythrophthalmus (from I??kl? dam), Tinca tinca (from I??kl? dam), C. carpio (from Karaca?ren dam), Carassius carassius (from Karaca?ren dam) caught from I??kl? and Karaca?ren. The highest metal was Na (466.95 μg/g) in C. carassius, while the lowest levels were Fe (0.37 μg/g) and Cu (0.37 μg/g) in C. carpio from I??kl? dam. The mean concentrations μg/g d.w. some of heavy metals in muscle of C. carpio (from I??kl? dam), S. erythrophthalmus (from I??kl? dam), T. tinca (from I??kl? dam), C. carpio (from Karaca?ren dam), C. carassius (from Karaca?ren dam) were as follows: Cd 2.00-2.10-1.95-2.06-2.27, Zn 4.36-2.64-13.13-13.33-24.47, Pb 1.65-1.24-1.90-2.37-2.41, Co 2.46-2.37-2.48-2.58-2.80, Mg 138.51-154.35-218.59-204.58-202.16, Fe 0.37-2.62-3.17-3.01-12.33, respectively. 相似文献
125.
Sediment quality guidelines (SQGs) can be derived using different approaches and are commonly used in environmental management,
reclamation, and risk assessment. The screening-level concentration (SLC) approach has been used in Ontario, Canada, to derive
lowest effect levels (LELs) and severe effect levels for use as SQGs. This approach was adopted by the Canadian Nuclear Safety
Commission (CNSC) to set guidelines for metals (As, Cr, Cu, Pb, Mo, Ni, Se, U, and V) and radionuclides (Ra-226, Pb-210, and
Po-210) in sediment at northern Saskatchewan uranium mining and milling operations. The SLC approach is based on total metal
and radionuclide concentrations in sediment, and corresponding benthic community composition data for a specific sampling
site. In this study, sediment chemistry (total metals and radionuclides) and benthic community data from northern Saskatchewan
uranium operations were compiled and examined. Results indicate that the CNSC-derived SQGs had limited relationships to observed
effects, or lack thereof, on benthic invertebrate communities near uranium operations in Saskatchewan. The LELs were found
to correctly align with effects at 95% of the sites that had effects, on a general basis, but on an element-specific basis
many of the elements had concentrations at effect sites below their LELs. Furthermore, concentrations of the evaluated elements
exceeded at least one LEL at 60% of the no-effect sites. The high number of exceedences of LELs at reference and no-effect
sites (false-positives) calls to question the appropriateness of the CNSC-derived SQGs. It is suggested that alternatives
to the SLC approach be explored. 相似文献
126.
A study of chemical and sedimentological parameters integrated with benthic foraminifera investigation was conducted along
the northern coast of Gabes Gulf. Thirty-two samples were studied and a total of 68 benthic foraminiferal species were identified.
Heavy metals enrichment factors and total hydrocarbon concentrations showed both metal and petrogenic pollution related mainly
to phosphogypsum, sewage, and fishing activities. Statistical analysis (bivariate correlation and hierarchical cluster analysis)
show a possible control of these pollutants on density, diversity, as well as the taxonomic composition of the benthic foraminiferal
assemblages. The extent to which the population was found less dense and less diversified corresponded to the degree to which
the sediment was contaminated. In these contaminated sites, an increase in relative abundance of opportunistic species such
Ammonia tepida and Haynesina germanica was found. Far from pollution, foraminiferal assemblages are dominated by species characteristic of Mediterranean shallow
water (Ammonia beccarii, Ammonia parkinsoniana, Elphidium crispum, Elphidium williamsoni, Elphidium advenum, Peneroplis planatus, Peneroplis pertesus). 相似文献
127.
Highways and main roads are a potential source of contamination for the surrounding environment. High traffic rates result in elevated heavy metal concentrations in road runoff, soil and water seepage, which has attracted much attention in the recent past. Nonetheless, investigations of pollutants in roadside soils are still a subject of major interest due to the rapid development of traffic systems and increasing traffic all over the world. The accumulation of the heavy metals Pb, Cd, Cu and Zn in soils along the oldest federal highway of the world has been studied by sampling a roadside transect of 125 by 10?m. In addition, heavy metal concentrations of Pb, Cd, Zn, Cu, Ni and Cr in soil solutions from different distances (2.5, 5 and 10?m) from the hard shoulder of the highway and from three soil depths (10, 30, and 50?cm) were investigated. The results show that heavy metal concentrations are up to 20 times increased compared to the geochemical background levels and a reference site of 800-m distance from the roadside. Soil matrix concentrations in the topsoil (0-10?cm) mostly exceeded the precautionary values of the German Federal Soil Protection and Contamination Ordinance (BBodSchV). The concentrations of Cd, Pb and Zn in the soil matrix tended to decrease with distance from the roadside edge, whereas the concentrations in the soil solution increased at a distance of 10?m onwards due to a lower soil pH. Because of both high pH values and a high sorption capacity of the soils, soil solution concentrations seldom exceeded the trigger values of the German Federal Soil Protection and Contamination Ordinance (BBodSchV) for transferring soil solution to groundwater. 相似文献
128.
Jasim?ImranEmail authorView authors OrcID profile Sadia?M.?Khan Carlos?Pirmez Gary?Parker 《Environmental Fluid Mechanics》2017,17(1):159-186
The scaling problem associated with the modeling of turbidity currents has been recognized but is yet to be explored systematically. This paper presents an analysis of the dimensionless governing equations of turbidity currents to investigate the scale effect. Three types of flow conditions are considered: (i) conservative density current; (ii) purely depositional turbidity current; and (iii) mixed erosional/depositional turbidity current. Two controlling dimensionless numbers, the Froude number and the Reynolds number, appear in the non-dimensional governing equations. When densimetric Froude similarity is satisfied, the analysis shows that the results would be scale-invariant for conservative density current under the rough turbulent condition. In the case of purely depositional flows, truly scale-invariant results cannot be obtained, as the Reynolds-mediated scale effects appear in the bottom boundary conditions of the flow velocity and sediment fall velocity. However, the scale effect would be relatively modest. The Reynolds effect becomes more significant for erosional or mixed erosional/depositional turbidity currents as Reynolds-mediated scale effects also appear in the sediment entrainment relation. Numerical simulations have been conducted at three different scales by considering densimetric Froude scaling alone as well as combined densimetric Froude and Reynolds similarity. Simulation results confirm that although the scaling of densimetric Froude number alone can produce scale-invariable results for conservative density currents, variations occur in the case of turbidity currents. The results become scale invariant when densimetric Froude and Reynolds similarities are satisfied simultaneously. 相似文献
129.
Andrea?AmicarelliEmail author Giovanni?Leuzzi Paolo?Monti Stefano?Alessandrini Enrico?Ferrero 《Environmental Fluid Mechanics》2017,17(4):715-753
Several reaction schemes, based on the conserved scalar theory, are implemented within a stochastic Lagrangian micromixing model to simulate the dispersion of reactive scalars in turbulent flows. In particular, the formulation of the reaction-dominated limit (RDL) reaction scheme is here extended to improve the model performance under non-homogeneous conditions (NHRDL scheme). The validation of the stochastic model is obtained by comparison with the available measurements of reactive pollutant concentrations in a grid-generated turbulent flow. This test case describes the dispersion of two atmospheric reactant species (NO and O3) and their reaction product (NO2) in an unbounded turbulent flow. Model inter-comparisons are also assessed, by considering the results of state-of-the-art models for pollutant dispersion. The present validation shows that RDL reaction scheme provides a systematic overestimation (relative error of ca. 85% around the centreline) in computing the local reactant consumption/production rate, whereas the NHRDL scheme drastically reduces this gap (relative error lower than 5% around the centreline). In terms of NO2 production (or reactant consumption), neglecting concentration fluctuations determines overestimations of the product mean of around 100% and a NO2 local production of one order of magnitude higher than the reference simulation. In terms of standard deviations, the concentration fluctuations of both the passive and reactive scalars are generally of the same order of magnitude or up to 1 or 2 orders of magnitudes higher than the corresponding ensemble mean values, except for the background reactant close to the plume edges. The study highlights the importance of modelling pollutant reactions depending on the instantaneous instead of the mean concentrations of the reactants, thus quantifying the role of the turbulent fluctuations of concentration, in terms of scalar statistics (mean, standard deviation, intensity of fluctuations, skewness and kurtosis of concentration, segregation coefficient, simulated reaction rate). This stochastic particle method represents an efficient numerical technique to solve the convection–diffusion equation for reactive scalars and involves several application fields: micro-scale air quality (urban and street-canyon scales), accidental releases, impact of odours, water quality and fluid flow industrial processes (e.g. combustion). 相似文献
130.
Organisms in the environment are exposed to a mixture of pollutants. Therefore the purpose of this study was to analyze the mutagenicity of organic and inorganic responses in two fractions of particulates (TSP and PM2.5) and extracts (organic and aqueous). The mutagenicity of organic and aqueous particulate matter extracts from urban-industrial and urban-residential areas was evaluated by Salmonella/microsome assay, through the microsuspension method, using strain TA98 with and without liver metabolization. Additionally, strains YG1021 and YG1024 (nitro-sensitive) were used for organic extracts. Aqueous extracts presented negative responses for mutagenesis and cytotoxicity was detected in 50% of the samples. In these extracts the presence of potential bioavailable metals was identified. All organic extracts presented mutagens with a higher potential associated with PM2.5. This study presents a first characterization of PM2.5 in Brazil, through the Salmonella/microsome assay. The evaluation strategy detected the anthropic influence of groups of compounds characteristically found in urban and industrial areas, even in samples with PM values in accordance with quality standards. Thus, the use of a genotoxic approach in areas under different anthropic influences will favor the adoption of preventive measures in the health/environment relation. 相似文献