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431.
Environmental and Ecological Statistics - 相似文献
432.
Kenneth F. Hedden Lee A. Mulkey William A. Tucker 《Environmental monitoring and assessment》1982,2(1-2):57-69
A potentially important exposure route for humans is the ingestion of chemicals via drinking water. If comprehensive exposure assessments are to be completed for either existing or proposed new chemicals and cost effective control strategies developed, then a quantitative understanding of multimedia transport and fate of specific chemical pollutants must be achieved. Mathematical models provide a powerful framework into which quantitative relationships may be placed to provide guidance in reaching water quality goals. Existing, state-of-the-art media-specific toxic organic transport and fate models for atmospheric (DiDOT), land surface (NPS) and surface water processes (EXAMS) and potable water treatment (WTP) have been linked to demonstrate the technical feasibility of such an approach. Limited application and sensitivity testing of this linked modeling system has shown that the impact of various source loadings and control strategies on drinking water quality can be estimated. 相似文献
433.
In recent years, suspended particle pollution has become a serious problem in Taiwan. The carbonaceous materials EC and OC
are play important roles in various atmospheric processes. The primary OC/EC ratio approach is applied to assess the contribution
of secondary organic aerosol (SOA) to the PM2.5 and PM10 mass at the Taichung harbor sampling site. The results indicated that the average EC and OC concentration were 1.06 and 6.50 μg
m−3, respectively, in fine particulate. And the average EC and OC concentration were 4.04 and 40.32 μg m−3, respectively, in coarse particulate at Taichung Harbor sampling site. In addition, and the average EC/OC rations was 8.72
in fine particle, respectively, at Taichung Harbor, Taiwan during summer and autumn period of 2005. The fine particle exhibited
high particulate concentrations in October, and lower concentration particulate occurred in August. And in this study OC and
EC concentrations in this study are compared with those in other cities. The results of EC and OC concentration in this study
are also compare with those other cities. 相似文献
434.
Yicai Huang Jiayuan Chen Qiannan Duan Yunjin Feng Run Luo Wenjing Wang Fenli Liu Sifan Bi Jianchao Lee 《Frontiers of Environmental Science & Engineering》2022,16(3):38
435.
The Taiwan Environmental Protection Administration (Taiwan EPA) launched a national Extended Producer Responsibility (EPR) system after integrating eight private recycling organizations in 1998. After that, the environmental performance of the EPR system brought a lot of attention to policy makers. Many studies show positive environmental effects of the EPR system in Taiwan. However, there are controversial questions remained, such as whether the performance indicators used are the right choice to estimate the environmental effects of the recycling policy? Can those estimated results really reflect the performance of the system?This paper would therefore like to more accurately evaluate the performance indicators of the EPR system based on data observed over the past decade in Taiwan. In the process of evaluating the performance indicators, we have found that the collection rates for durable goods are often ignored in countries that pursue a zero waste policy. This may affect the actual recycling outcome and resource direction targeted by producers. However, in order for the collection rate to be adopted as a policy indicator, how to estimate the amounts of retired or waste products during a period is critical. In this paper, we estimate the collection rate for electrical and electronic waste by using the survival analysis and ownership data analysis approaches. We also provide a comparison of both approaches and put forward suggestions for directions in the future in solid waste management. 相似文献
436.
Distribution of polycyclic aromatic hydrocarbons in agricultural soils in South Korea 总被引:32,自引:0,他引:32
The content and type of polycyclic aromatic hydrocarbons (PAH) in soils from paddy fields and upland areas in South Korea were determined using gas chromatography linked to mass spectrometry (GC–MS). The distribution map of total PAH content was obtained as a contour plot using a geographical information system. The overall distribution of PAH was found to be closely related to the pollution sources, the size of city and the type of industry. The average content of total PAH in all samples was 236 μg kg−1, and the range was from 23.3 to 2834 μg kg−1. The highest concentrations were found in soils sampled near iron processing plants. The concentration of PAH decreased in the order fluoroanthene>benzo(b)fluoroanthene>pyrene. Special PAH compound ratios, such as phenanthrene/anthracene and fluoroanthene/pyrene, were calculated to evaluate the origin. The collected data suggested that the pyrogenic origins such as motor vehicle exhaust and heavy industry emission were the dominant source of PAH in Korean soils. 相似文献
437.
Perceiving the Environment from the Lay Perspective in Desertified Areas,Northern China 总被引:1,自引:0,他引:1
Investigating local people’s environmental perceptions can produce useful information that could be incorporated into decision
making processes that help resolve environmental problems. Although China is undergoing severe desertification, the perceptions
of the local people toward their degraded environment and the related issues have so far not been actively solicited. This
article, which is a supplement to Lee and Zhang’s (2004, 2005) studies, seeks to further investigate the lay public’s general environmental attitudes, perceptions of desertification, interpretations
of land-degrading activities, and particularly their interrelations in severely desertified areas. Minqin County in Gansu
Province, northern China, was chosen to be the study area. Data was collected via a questionnaire survey (n = 1138) administered in December 2002. Major findings were: (1) Most respondents had only weak altruistic environmental attitudes,
with educational level to be a significant determinant. (2) Respondents’ perceptions of desertification and interpretations
of land-degrading activities were contingent on personal attributes, general environmental attitudes, and other conceptions
related to desertification. It is recommended that the interrelations between the various aspects of the public’s environmental
perceptions should be thoroughly examined to facilitate their participation in environmental management. 相似文献
438.
Across the globe, continued policy debates regarding the management of old-growth forests center around the difficult task of balancing economic and ecological considerations. Though the forests of the Pacific Northwest United States are among the most studied old-growth ecosystems, ecological and economic analyses have yielded public land management directives that remain controversial. Specifically, the recently adopted Northwest Forest Plan lacks explicit goals for maintaining intergenerational equity for the use of forest resources and the diversity of old-growth ecosystems. Unlike previous studies which rely on monetary quantification of costs and benefits, this study develops and applies a conceptual framework for evaluating socially optimal Pacific Northwest old-growth forest utilization strategies. Conditions for the optimal management of old-growth forests are derived using dynamic programming. The objective function synthesizes relevant biological and economic attributes of the old-growth allocation problem. Results in the form of extraction paths are compared given social pressure for consumptive and non-consumptive benefits, as well as different planning horizons, rates of social time preference, and environmental variance. Lengthening the planning horizon results in a vast divergence of optimal policies in the absence of discounting. Extraction rates appear to approach zero as the planning horizon approaches infinity. While higher rates of social time preference increase the rate of extraction, forest stocks remaining at the terminal time period equal levels remaining with a lower discount rate. Increasing environmental variance results in a higher level of stock remaining at the terminal time period. This analysis, while specific to the old-growth controversy of the Pacific Northwest, does provide general guidelines for addressing similar problems of multiple uses of natural areas, particularly where such uses are mutually incompatible, or where one use may be irreversibly destructive to another. 相似文献
439.
This paper provides details of a dynamic compartment model for estimating the (14)C radioactivity in an agricultural plant exposed to an amount of airborne (14)CO(2) gas. The plant, in the model, is divided into two compartments, the plant body (shoot and root) and ears, to predict the radioactivity of different parts of a plant. The carbon transports from, to and between the compartments are described by the processes of a photosynthesis, respiration, and translocation. The carbon transport fluxes of these processes are determined from the growth rates of a plant, which are usually easily attained. The model predictions showed that the present model could converge to a region where the specific activity model is applicable when the elapsed exposure time was extended up to the harvest time of a plant. The (14)C activity of a plant was greatly affected by the elapsed exposure time, the developmental stages of a plant at an exposure time, and the airborne (14)C activity during an exposure. It was expected that the peak of the ears' (14)C activity appeared when the exposure time was close to the ears-maturity date. The model predictions agreed reasonably well with the measured (14)C radioactivity of the rice plants that were artificially exposed to (14)CO(2) of a high (14)C source for a short period of time in an exposure box. 相似文献
440.
Along with the world population increase, meat requirement has been also increasing; thus, massive livestock manure has been released leading to problems due to surplus nutrients. To overcome this situation, we should consider availing some nutrient removal or reuse technology. The commonest way to recover resources from livestock manure is by producing liquid fertilizer and compost. However, some technologies are required to make it easier and safer for transportation and handling of manure fertilizer due to various problems such as poor fertilization quality with low maturity, emission of odor, nutrient loss, and disharmony due to fluctuating seasonal and regional supplies and demands. In this study, available technologies for resource recovery from animal wastes were introduced with economic benefits, and an integrated system was proposed including energy flow. The system consisted of anaerobic digestion or microbial fuel cell, struvite precipitation for P recovery, nitrogen enrichment by mechanical vapor compression distillation, and incineration processes (optional). Consequently, the energy output from the system could be sufficient for operating the entire system without the need for extra energy input. 相似文献