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1.
Product quality-based eco-efficiency applied to digital cameras   总被引:1,自引:0,他引:1  
When calculating eco-efficiency, there are considerable confusion and controversy about what the product value is and how it should be quantified. We have proposed here a quantification method for eco-efficiency that derives the ratio of the multiplication value of the product quality and the life span of a product to its whole environmental impact based on Life Cycle Assessment (LCA). In this study, product quality was used as the product value and quantified by the following three steps: (1) normalization based on a value function, (2) determination of the subjective weighting factors of the attributes, and (3) calculation of product quality of the chosen products. The applicability of the proposed method to an actual product was evaluated using digital cameras. The results show that the eco-efficiency values of products equipped with rechargeable batteries were higher than those products that use alkaline batteries, because of higher quality values and lower environmental impacts. The sensitivity analysis shows that the proposed method was superior to the existing methods, because it enables to identify the quality level of the chosen products by considering all products that have the same functions in the market and because, when adding a new product, the calculated quality values in the proposed method do not have to be changed.  相似文献   

2.
The guild concept applied to management of bird populations   总被引:5,自引:0,他引:5  
Alternative ways to apply the guild concept to wildlife management are evaluated here. I reject the idea that indicator species can be selected for each bird guild to reduce costs of environmental assessment and monitoring. Promise is seen, however, in the option of using whole guilds to indicate the capability of habitat zones to support populations of wildlife species. It may be adequate for most management purposes to delineate guilds only for species that use an environment for breeding, because transients and winter residents probably use the same zones of the habitat in the same ways. Potential guilds are identified by cells of a two-dimensional matrix, the axes identifying primary feeding and nesting zones. Some questions may be answered with guilds as delineated by all cells in the matrix. Alternatively, larger guilds can be formed by grouping all species in each column or row of the matrix to identify, for example, all species that depend on tree canopies for foraging, or tree boles for nesting. One can also consider separately the resident breeders, migrant breeders, and winter residents to obtain insights into whether observed changes in numbers of birds in a guild are a result of conditions locally or elsewhere. I conclude that the guild concept probably has a place in wildlife management, but much testing must be done before it is widely applied.  相似文献   

3.
针对长春市存在污染的46个土壤采样点,以Hg、Cd、Pb、As、Cu、Cr、Zn七种重金属元素指标作因子分析,从而为长春市表层土壤重金属污染成因的解释提供一定的理论依据。  相似文献   

4.
We measure the trapped non-wetting phase saturation as a function of the initial saturation in sand packs. The application of the work is for CO2 storage in aquifers where capillary trapping is a rapid and effective mechanism to render injected CO2 immobile. The CO2 is injected into the formation followed by chase brine injection, or natural groundwater flow, which displaces and traps CO2 on the pore scale as a residual immobile phase. Current models to predict the amount of trapping are based on experiments in consolidated media, while CO2 may be stored in relatively shallow, poorly consolidated systems. We use analogue fluids at ambient conditions. The trapped saturation initially rises linearly with initial saturation to a value of approximately 0.13 for oil/water systems and 0.14 for gas/water systems. There then follows a region where the residual saturation is constant with further increases in initial saturation. This behaviour is not predicted by the traditional literature trapping models, but is physically consistent with unconsolidated media where most of the larger pores can easily be invaded at relatively low saturation and there is, overall, relatively little trapping. A good match to our experimental data was achieved with the trapping model proposed by Aissaoui.  相似文献   

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7.
Sewage sludge (SS) applied to sloping fields at rates that exceed annual forest nutrient requirements can be a source of phosphorus (P) in runoff. This study investigates the effects of different slopes (18, 27, 36, and 45%) on P in runoff from plots amended with SS (120 Mg ha). Lateritic soil (pH 5.2) was exposed to five simulated rainfalls (90 mm h) on outdoor plots. When sludge was broadcast and mixed with surface soils, the concentrations and loss in runoff of total P in the mixed sample (MTP), total P in the settled sample (STP), total particulate P (TPP), total suspended P (TSP), and total dissolved P (TDP) were highest at 1 or 18 d after application. Initially, pollution risks to surface waters generally increased to different degrees with steeper slopes, and then diminished gradually with dwindling differences between the slopes. The runoff losses coefficient of MTP increased in the order 36 > 45 > 27 > 18%. The initial event (1 and 18 d) accounted for 67.0 to 83.6% of total runoff P losses. Particulate fraction were dominant carriers for P losses, while with the lower slopes there was higher content of P per unit particulate fraction in runoff. Phosphorus losses were greatly affected by the interaction of sludge-soil-runoff and the modification of soil properties induced by sludge amendment. It is recommended to choose lower slopes (<27%) to reduce risk of P losses. Thus, the risk of application sludge to sloping fields in acid soils should be studied further in the field under a wider diversity of conditions.  相似文献   

8.
A promising alternative to conventional single phase processing, the use of sequential anaerobic-aerobic digestion, was extensively investigated on municipal sewage sludge from a full scale wastewater treatment plant. The objective of the work was to evaluate sequential digestion performance by testing the characteristics of the digested sludge in terms of volatile solids (VS), Chemical Oxygen Demand (COD) and nitrogen reduction, biogas production, dewaterability and the content of proteins and polysaccharides. VS removal efficiencies of 32% in the anaerobic phase and 17% in the aerobic one were obtained, and similar COD removal efficiencies (29% anaerobic and 21% aerobic) were also observed. The aerobic stage was also efficient in nitrogen removal providing a decrease of the nitrogen content in the supernatant attributable to nitrification and simultaneous denitrification. Moreover, in the aerobic phase an additional marked removal of proteins and polysaccharides produced in the anaerobic phase was achieved. The sludge dewaterability was evaluated by determining the Optimal Polymer Dose (OPD) and the Capillary Suction Time (CST) and a significant positive effect due to the aerobic stage was observed. Biogas production was close to the upper limit of the range of values reported in the literature in spite of the low anaerobic sludge retention time of 15 days. From a preliminary analysis it was found that the energy demand of the aerobic phase was significantly lower than the recovered energy in the anaerobic phase and the associated additional cost was negligible in comparison to the saving derived from the reduced amount of sludge to be disposed.  相似文献   

9.
This paper reviews the effects of six post-modern management concepts as applied to Turkish forestry. Up to now, Turkish forestry has been constrained, both in terms of its operations and internal organization, by a highly bureaucratic system. The application of new thinking in forestry management, however, has recently resulted in new organizational and production concepts that promise to address problems specific to this Turkish industry and bring about positive changes. This paper will elucidate these specific issues and demonstrate how post-modern management thinking is influencing the administration and operational capacity of Turkish forestry within its current structure.  相似文献   

10.
11.
There is increasing concern about the environmental fate and impact of biosolids-associated anthropogenic organic chemicals, among which 4-nonylphenol (4-NP) is one of the most studied chemicals. This is primarily because 4-NP is an endocrine disruptor and has been frequently detected in environmental samples. Due to its high hydrophobicity, 4-NP has high affinity for biosolids. Land application of 4-NP-containing biosolids could potentially introduce large quantities of this chemical into the environment. A laboratory experiment was conducted to investigate the effect of artificial sunlight on 4-NP degradation in biosolids applied to soil. When exposed to artificial sunlight for 30 d, the top-5-mm layer of biosolids showed a 55% reduction of 4-NP, while less than 15% of the 4-NP was degraded when the biosolids were kept in the dark. Our results indicate that sensitized photolysis reaction plays an important role in reducing the levels of 4-NP in land-applied biosolids. Surface application rather than soil incorporation of biosolids could be effective in reducing biosolids-associated organic chemicals that can be degraded through photolysis reactions. However, the risks of animal ingestion, foliar deposition, and runoff should also be evaluated when biosolids are applied on the soil surface.  相似文献   

12.
Movement of nutrients from livestock manure handling sites has the potential to negatively impact the environment. This study was conducted using electromagnetic induction (EMI) measurements to develop apparent soil electrical conductivity (EC(a)) maps to identify regions of nutrient buildup beneath an abandoned compost site. A trailer-mounted EM-38 coupled with a global positioning satellite system was towed across an area used for composting of feedlot manure. The resulting EC(a) maps were compared with known locations of compost rows confirming the alignment of row locations with high EC(a) regions. The identified rows were cored and compared with the region between the rows. The identified rows with a compost history demonstrated significant (P < 0.05) increases in soluble salts (1.6 times greater), NO3 (6.0 times greater), and Cl (2.0 times greater) compared with the area between the rows at a 1.5-m depth. Image processing techniques were used to display yearly changes that were associated with nutrient movement and transformations in the soil beneath the site. Correlations between EMI measurements and soil core analyses for NO3-N, Cl, and EC provided ancillary support for the EMI methods. The use of EMI for mapping of sites having a history of livestock waste application was effective in delineating high nutrient buildup areas and for observing spatial EC(a) changes over time.  相似文献   

13.
This article is the first in a series of three. These articles were prepared to document the growth management process undertaken in Teller County, Colorado, USA. In this article, an 11-step method for landscape planning is proposed. In step 1, an issue, or set of related issues, is identified as posing a problem and/or opportunity to people and/or the environment. In step 2, a goal, or several goals, is established to address the problem or opportunity. In steps 3 and 4, inventories and analyses of biophysical and sociocultural processes are conducted, first at the regional level and then at the local level. Step 5 involves detailed studies (such as suitability analyses) that link the inventory and analysis information to the problems or opportunities and goals. Detailed studies link regional and local information to specific sites. Thus, this method involves a regional-local-specific site hierarchy. In step 6, concepts are developed that lead to a landscape plan in step 7. During step 8, the plan is explained through a systematic educational and citizen involvement effort to the affected public. In step 9, detailed designs are developed that again are explained to the specific individuals who will be impacted by the designs. It is in step 10 when the plan and designs are implemented. Step 11 involves the administration of the plan. The method is illustrated through an example of growth management planning for Teller County and the city of Woodland Park, Colorado. Paper 1 in a series of 3.  相似文献   

14.
Permanent grass vegetation on sloping soils is an option to protect fields from erosion, but decaying grass may liberate considerable amounts of dissolved reactive P (DRP) in springtime runoff. We studied the effects of freezing and thawing of grassed soil on surface runoff P concentrations by indoor rainfall simulations and tested whether the peak P concentrations could be reduced by amending the soil with P-binding materials containing Ca or Fe. Forty grass-vegetated soil blocks (surface area 0.045 m, depth 0.07 m) were retrieved from two permanent buffer zones on a clay and loam soil in southwest Finland. Four replicates were amended with either: (i) gypsum from phosphoric acid processing (CaSO × 2HO, 6 t ha), (ii) chalk powder (CaCO, 3.3 t ha), (iii) Fe-gypsum (6 t ha) from TiO processing, or (iv) granulated ferric sulfate (Fe[SO], 0.7 t ha), with four replicates serving as untreated controls. Rainfall (3.3 h × 5 mm h) was applied on presaturated samples set at a slope of 5% and the surface runoff was analyzed for DRP, total dissolved P (TDP), total P (TP), and suspended solids. Rainfall simulation was repeated twice after the samples were frozen. Freezing and thawing of the samples increased the surface runoff DRP concentration of the control treatment from 0.19 to 0.46 mg L, up to 2.6-3.7 mg L, with DRP being the main P form in surface runoff. Compared with the controls, surface runoff from soils amended with Fe compounds had 57 to 80% and 47 to 72% lower concentrations of DRP and TP, respectively, but the gypsum and chalk powder did not affect the P concentrations. Thus, amendments containing Fe might be an option to improve DRP retention in, e.g., buffer zones.  相似文献   

15.
The wetland ecosystems occurring within alluvial floodplains change rapidly. Within the ecological successions, the life span of pioneer and transient stages may be measured in several years or decades depending on the respective influences of allogenic (water dynamics, erosion, and deposition) and autogenic developmental processes (population dynamics, eutrophication, and terrestrialization). This article emphasizes the mechanisms that are responsible for the ecosystem changes and their importance to environmental management. Two case studies exemplify reversible and irreversible successional processes in reference to different spatial and temporal scales. On the scale of the former channels, the standing-water ecosystems with low homeostasis may recover their previous status after human action on the allogenic processes. On the scale of a whole reach of the floodplain, erosion and deposition appear as reversible processes that regenerate the ecological successions. The concepts of stability and reversibility are discussed in relation to different spatiotemporal referential frameworks and different levels of integration. The reversible process concept is also considered with reference to the energy inputs into the involved subsystems. To estimate the probability of ecosystem regeneration or the cost of restoration, a concept of degrees of reversibility is proposed.  相似文献   

16.
We tested two cutting regimens (cut/spray and cut/delay spray) and four radiarc-applied herbicides (Garlon + Tordon, Accord, Accord + Escort, and Krenite) in an Ohio power-line corridor to determine which management combination best eliminated target species (i.e., trees) and preserved nontarget species (i.e., low shrubs, vines, perennial herbs, and grasses). When spraying was delayed after cutting, the herbicide with the least impact on nontarget species (Krenite) also was least efficient at killing target trees. Spraying soon after cutting improved tree-killing efficiency of several herbicides, but it also increased the negative impact on nontarget species. The herbicide with the most consistent tree-killing ability (Accord + Escort) had the most impact on nontarget species. Because none of the herbicide/cutting treatments performed ideally, resource managers must decide the acceptable impact on nontarget species when considering herbicide use. Future success of herbicides as part of an integrated succession management approach requires more selective application methods and formulations so that target effects can be maximized and nontarget effects can be minimized.  相似文献   

17.
This article reviews the application of environmental impact assessment (EIA) procedures and practices to three watershed modification projects situaled in western Canada. These ventures were justified for accelerating regional economic development, and cover the period during which public concerns for protecting the environment rapidly made their way into the national political agenda. An historical account and analysis of the situation, therefore, seems desirable in order to understand the development of EIA processes, practices, and methodologies since the start of construction of the first project in 1961. This study concludes that there has been good progress in predicting and evaluating environmental and related social impacts of watershed modification proposals. However, a number of obstacles need to be overcome before EIA can firmly establish itself as an effective planning tool. These difficulties include jurisdictional confusions and conflicts, division of authority and responsibility in designing and implementing appropriate mitigative and monitoring measures, lack of tested EIA methodologies, and limited availability of qualified human resources. A number of conclusions and suggestions are offered so that future watershed modification proposals may be planned and implemented in a more environmentally sustainable fashion. These include: (1) EIA processes must be completed before irrevocable decisions are made. (2) Any major intrusion into a watershed is likely to impact on some major components of the ecosystem(s). (3) Mitigation costs must form part of the benefit-cost analysis of any project proposal. (4) Interjurisdictional cooperation is imperative where watersheds cross political boundaries. (5) The EIA process is a public process, hence public concerns must be dealt with fairly. (6) The role of science in the EIA process must be at arms length from project proponents and regulators, and allowed to function in the interest of the protection of the environment and public health and safety. The views expressed here are the authors’ own and do not necessarily reflect those of FEARO and/or other government agencies and officials involved in the review of these projects.  相似文献   

18.
Soil contamination by arsenic (As) presents a hazard in many countries and there is a need for techniques to minimize As uptake by plants. A proposed in situ remediation method was tested by growing lettuce (Lactuca sativa L. cv. Kermit) in a greenhouse pot experiment on soil that contained 577 mg As kg(-1), taken from a former As smelter site. All combinations of iron (Fe) oxides, at concentrations of 0.00, 0.22, 0.54, and 1.09% (w/w), and lime, at concentrations of 0.00, 0.27, 0.68, and 1.36% (w/w), were tested in a factorial design. To create the treatments, field-moist soil, commercial-grade FeSO4, and ground agricultural lime were mixed and stored for one week, allowing Fe oxides to precipitate. Iron oxides gave highly significant (P < 0.001) reductions in lettuce As concentrations, down to 11% of the lettuce As concentration for untreated soil. For the Fe oxides and lime treatment combinations where soil pH was maintained nearly constant, the lettuce As concentration declined in an exponential relationship with increasing FeSO4 application rate and lettuce yield was almost unchanged. Iron oxides applied at a concentration of 1.09% did not give significantly lower lettuce As concentrations than the 0.54% treatment. Simultaneous addition of lime with FeSO4, was essential. Ferrous sulfate with insufficient lime lowered soil pH and caused mobilization of Al, Ba, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Sr, and Zn. At the highest Fe oxide to lime ratios, Mn toxicity caused severe yield loss.  相似文献   

19.
Forest networks     
Summary A study beyond the political boundaries in planning strategies for long-term management of the global forest estate is presented. Three alternative forest networks are proposed: (1) the genetic-evolutionary network, based around common evolutionary features, thus delineating similar forest types where conservation and management issues are likely to be compatible; (2) the current ecological and environmental network, based around the role that forests play in the wider ecosystem, including regular and irregular migration pathways, networks to absorb the impact of climate change, water filters etc; (3) the human impact network, based on the history of human involvement in the forest and its implications. The practical policy significance of the various networks is discussed in turn.This paper was researched as part of a project carried out for the World Wide Fund for Nature (WWF). Nigel Dudley is an ecologist, based in the UK, with 15 years experience as a consultant for NGOs, local government and international organizations. He is a former director of the Soil Association and now works with Equilibrium Consultants at the above address. For the past five years he has worked closely with WWF on forest conservation projects and has written several reports for the organization, includingForests in trouble: a review of the status of temperate forests worldwide.  相似文献   

20.
Land applications of manure from confined animal systems and direct deposit by grazing animals are both major sources of nutrients in streams. The objectives of this study were to determine the effects of P-based manure applications on total suspended solids (TSS) and nutrient losses from dairy manures and poultry litter surface applied to pasturelands and to compare the nutrient losses transported to the edge of the field during overland flow events. Two sets of plots were established: one set for the study of in-field release and another set for the study of edge-of-the-field nutrient transport. Release plots were constructed at three pastureland sites (previous poultry litter applications, previous liquid dairy manure application, and no prior manure application) and received four manure treatments (turkey [Meleagris gallopavo] litter, liquid dairy manure, standard cowpies, and none). Pasture plots with a history of previous manure applications released higher concentrations of TSS and higher percentages of total P (TP) in the particulate form. Transport plots were developed on pasture with no prior manure application. The average flow-weighted TP concentrations were highest in runoff samples from the plots treated with cowpies (1.57 mg L(-1)). Reducing excess P in dairy cow diets and surface applying manure to the land using P-based management practices did not increase N concentrations in runoff. This study found that nutrients are most transportable from cowpies; thus a buffer zone between pastureland and streams or other appropriate management practices are necessary to reduce nutrient losses to waterbodies.  相似文献   

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