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651.
Chemical mass balance (CMB) and trajectory receptor models were applied to speciated particulate matter with aerodynamic diameter < or =2.5 microm (PM2.5) measurements from Speciation Trends Network (STN; part of the Chemical Speciation Network [CSN]) and Interagency Monitoring of Protected Visual Environments (IMPROVE) monitoring network across the state of Minnesota as part of the Minnesota PM2.5 Source Apportionment Study (MPSAS). CMB equations were solved by the Unmix, positive matrix factorization (PMF), and effective variance (EV) methods, giving collective source contribution and uncertainty estimates. Geological source profiles developed from local dust materials were either incorporated into the EV-CMB model or used to verify factors derived from Unmix and PMF. Common sources include soil dust, calcium (Ca)-rich dust, diesel and gasoline vehicle exhausts, biomass burning, secondary sulfate, and secondary nitrate. Secondary sulfate and nitrate aerosols dominate PM2.5 mass (50-69%). Mobile sources outweigh area sources at urban sites, and vice versa at rural sites due to traffic emissions. Gasoline and diesel contributions can be separated using data from the STN, despite significant uncertainties. Major differences between MPSAS and earlier studies on similar environments appear to be the type and magnitude of stationary sources, but these sources are generally minor (<7%) in this and other studies. Ensemble back-trajectory analysis shows that the lower Midwestern states are the predominant source region for secondary ammoniated sulfate in Minnesota. It also suggests substantial contributions of biomass burning and soil dust from out-of-state on occasions, although a quantitative separation of local and regional contributions was not achieved in the current study. Supplemental materials are available for this article. Go to the publisher's online edition of the Journal of the Air & Waste Management Association for a summary of input data, Unmix and PMF factor profiles, and additional maps.  相似文献   
652.
This article quantifies the nature, frequency, and cost of environmental remediation activities for onshore oil and gas operations, as determined from over 4,100 environmental remediation cases in Texas, Kansas, New Mexico, and Colorado. For the purpose of this article, “remediation'' refers to cleanup efforts that entail longer‐term site characterization, monitoring, and remedial action beyond the initial spill cleanup or emergency response stage. In addition, data are also presented regarding short‐term spill cleanup activities in two of the four states. © 2011 Wiley Periodicals, Inc.  相似文献   
653.
Participatory scenario development for integrated sustainability assessment   总被引:1,自引:0,他引:1  
The paper discusses the role of visions within sustainability assessment and governance for sustainable development in Europe. Currently, our societies (still) develop along an unsustainable path, which results in a number of persistent problems (climate change, loss of biodiversity, poverty, etc.). Integrated sustainability assessment (ISA) is one approach designed to initiate transitions towards sustainability. Visions of a sustainable future form an important part of ISA. These visions support the process of discussing how the transition from today’s societies/systems to a sustainable future can be achieved. According to the principles of ISA, visions should be developed in a participatory way, thus including the ideas and perceptions of stakeholders, decision-makers, experts and/or citizens. The paper starts with an introduction of the concepts of visions and scenarios and describes exemplary methods for their participatory development. Then, the main concepts for integrated sustainability assessment in comparison with other impact assessments are discussed. The main body of the paper presents experiences in three projects (ARTEMIS, ALARM, ECOCHANGE) in which visions and scenarios of sustainable futures were developed with stakeholders. The paper concludes with lessons learned and suggestions for future applications for participatory scenario development.  相似文献   
654.
The effect of atmospheric nitrogen deposition on the species richness of acid grasslands was investigated by combining data from a large Danish monitoring program with a large European data set, where a significant non-linear negative effect of nitrogen deposition had been demonstrated (Stevens et al., 2010). The nitrogen deposition range in Denmark is relatively small and when only considering the Danish data a non-significant decrease in the species richness with nitrogen deposition was observed. However, when both data sets were combined, then the conclusion of the European survey was further corroborated by the results of the Danish monitoring. Furthermore, by combining the two data sets a more comprehensive picture of the threats to the biodiversity of acid grasslands emerge; i.e., species richness in remnant patches of acid grassland in intensively cultivated agricultural landscapes is under influence not only from nitrogen deposition, but also from current and historical land use.  相似文献   
655.
Although implementing conservation practices on private farms and forests can produce substantial environmental benefits, these practices are not being adopted widely enough to result in measurable improvements at regional scales. Researchers have investigated the production and program factors influencing producer choices to voluntarily adopt these practices. However, the findings of reviews are inconsistent, raising questions about review methods, including the omission of relevant variables. Further, applying lessons from past work to promote adoption is difficult because many reviews investigated dispositional or demographic variables that practitioners and policy makers cannot directly observe or influence. We conducted a new review of 146 empirical studies that tested the effects of different interventions (e.g., financial incentives, outreach events, and nudges) on increasing the likelihood of producers adopting conservation practices. We conducted a metaregression of quantitative studies from diverse disciplines that filtered studies by quality (i.e., use of randomization and clear analysis reporting). We synthesized these results with a thematic analysis of qualitative studies on producer perspectives about conservation practices. Financial incentives had the strongest evidence of increasing producers’ likelihood of adopting conservation practices (odds ratio 1.86, p < 0.05). However, this effect was only apparent after filtering by study quality, which also improved model fit and identified significant regional differences (odds ratio –1.69, p < 0.01). The thematic review of qualitative studies revealed that peer groups may be successful in reinforcing adoption behaviors due to homophily effects and that financial incentives not only offset implementation costs but also mitigated perceived risks of adoption. Given the problems we encountered in testing hypotheses about the magnitude of variability explained by intervention types and practice characteristics, we recommend additional experimental and longitudinal work that accounts for financial incentives and pairs qualitative and quantitative data to clarify relationships between program design and practice adoption rates.  相似文献   
656.
This paper presents results from laboratory studies to measure the methane yield and rate of digestion of reject bananas. These parameters were determined in experiments that took into account the likely configuration of a full-scale plant in the banana growing region of north Queensland. The digestion was conducted in a 200-l reactor using fed-batch operation, relying entirely on the natural microbial consortia on the reject bananas to avoid reliance on external inocula such as sludge, an undesirable material around food packaging facilities. An enrichment culture was first established in a highly buffered 200-l batch digestion unit. The fed-batch digester was then started by exchanging leachate with the mature batch reactor. Under loading conditions of 0.6 kg VS m(-3)d(-1) over 70 days where the average working volume was 160 l, the digester produced 398+/-20 l CH4 kg VS(-1). Increasing the loading rate to 1.6 kg VS m(-3)d(-1) resulted in a reduced methane yield of 210 l CH4 kg VS(-1) over 23 days of operation, with a concomitant accumulation of banana waste in the digester. The leachate at the end of digestion contained over 4000 mg l(-1)K, 200 mg l(-1) N and 75 mg l(-1), levels that exceed acceptable limits for general agricultural irrigation.  相似文献   
657.
Methods for household waste composition studies   总被引:1,自引:0,他引:1  
The question is how to conduct household waste composition studies. The review is divided into three parts: overview of known methods, sampling theory, and the waste components. Twenty methods are listed and commented on. There is no adopted, working international standard. In accordance with Pierre Gy's Theory of Sampling, the seven types of sampling errors, when collecting and splitting solid samples, are described and commented on in relation to sampling of household solid waste. It is concluded that the most crucial choices in household waste composition studies are: to divide the investigation into relevant number and types of strata; to decide the required sample size and number of samples; to choose the sampling location, i.e., sampling at household level or sampling from loads of waste collection vehicles; and to choose the type and number of waste component categories to be investigated. Various classifications of household waste components used in composition studies are listed and discussed. Difficulties and weaknesses of the reviewed methods are discussed and concluded in suggested questions for further research.  相似文献   
658.
The study of mechanisms controlling preferential flow and transport in variably saturated fractured clayey till is often hindered by insufficient spatial resolution or unknown measuring volume. With the objective to study these mechanisms while circumventing the obstacles, tracer experiments with two fluorescent tracers Acid Yellow 7 (AY7) and Sulforhodamine B (SB) were performed at three different rain events for a fall and a summer season. Irrigated areas were excavated down to depths of 2.8 m and the movement of both tracers in the exposed profiles was delineated simultaneously by high spatial resolution apparent concentration maps (pixel approximately 1 mm(2)) obtained with an imaging device. The device consists of a light source and a CCD camera, both equipped with tracer-specific-filters for fluorescent light. The fluorescence images were corrected for nonuniform lighting, changing surface roughness, and varying optical properties of the soil profile. The resulting two-dimensional apparent concentration distribution profiles of the tracers showed that: (i) relative low water content in the upper 10 cm of the irrigated till in summer had a pronounced retardation effect on the AY7-migration and no effect on the SB-migration; (ii) the dead-end biopores were not activated in the fall season; (iii) only 3D fracture-plans connected to hydraulically active 1D-biopores contributed to the leaching; (iv) the tracer migration primary followed macropores during both seasons, though AY7 also followed a topsoil piston transport in summer; (v) the highest tracer pixel apparent concentrations were often found in macropores and most pronounced in the summer season; and (vi) 3D-dilution in fractures seems to play a dominating role in AY7-migration in the fall season.  相似文献   
659.
This article presents a methodological framework for strategic environmental assessment (SEA) application. The overall objective is to demonstrate SEA as a systematic and structured policy, plan, and program (PPP) decision support tool. In order to accomplish this objective, a stakeholder-based SEA application to greenhouse gas (GHG) mitigation policy options in Canadian agriculture is presented. Using a mail-out impact assessment exercise, agricultural producers and nonproducers from across the Canadian prairie region were asked to evaluate five competing GHG mitigation options against 13 valued environmental components (VECs). Data were analyzed using multi-criteria and exploratory analytical techniques. The results suggest considerable variation in perceived impacts and GHG mitigation policy preferences, suggesting that a blanket policy approach to GHG mitigation will create gainers and losers based on soil type and associate cropping and on-farm management practices. It is possible to identify a series of regional greenhouse gas mitigation programs that are robust, socially meaningful, and operationally relevant to both agricultural producers and policy decision makers. The assessment demonstrates the ability of SEA to address, in an operational sense, environmental problems that are characterized by conflicting interests and competing objectives and alternatives. A structured and systematic SEA methodology provides the necessary decision support framework for the consideration of impacts, and allows for PPPs to be assessed based on a much broader set of properties, objectives, criteria, and constraints whereas maintaining rigor and accountability in the assessment process.  相似文献   
660.
Manado is the largest and most densely populated coastal city in North Sulawesi Province, Indonesia. The city is facing problems of wastewater discharged from various sources. These problems are driven by high population pressure, increasing economic activity, and low household income, in combination with inadequate organizational structure of government institutions for addressing the wastewater problems as well as for law enforcement. There have been no community initiatives to prevent or mitigate wastewater problems. Therefore, a wastewater management plan is urgently needed to prevent and mitigate pollution caused by discharged wastewater. In this paper we analyze the current situation with respect to environmental state, sources and treatment of wastewater, socio-economic and institutional capacities as well as community awareness. Constraints and potentials are discussed to give recommendations for an integrated wastewater management plan for the city of Manado.  相似文献   
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