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To investigate the methane and carbon dioxide emissions from landfill, samples were taken of material up to 5 years old from Shan-Chu-Ku landfill located in the northern part of Taiwan. Atmospheric concentrations of carbon dioxide, methane and nitrous oxide ranged from 310 to 530, 2.64 to 20.16 and 0.358 to 1.516 ppmv with the measurement of gas-type open-path Fourier transform infra-red (FTIR) spectroscopy during February 1998 to March 2000, respectively. Average methane emission rate was 13.17, 65.27 and 0.99 mgm(-2)h(-1) measured by the gas chromatography chamber method in 1-2, 2-3 and 5 year-old landfill, respectively. Similarly, average carbon dioxide emission rate was 93.70, 314.60 and 48.46 mgm(-2)h(-1), respectively. About 2-3 year-old landfill had the highest methane and carbon dioxide emission rates among the tested areas, while 5 year-old landfill was the least. Methane emission rate at night in most tested locations was higher than that in the daytime. Total amount of methane and carbon dioxide emission from this landfill was around 171 and 828 ton in 1999, respectively. 相似文献
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Singhal RK Preetha J Karpe R Tirumalesh K Kumar SC Hegde AG 《Environment international》2006,32(2):224-228
During this work, size fractionation technique "ultra filtration" is used in speciation studies of trace elements in the coastal sea water. Filtration is the most commonly used method to fractionate trace metal species, but often only "dissolved" and "particulate" fraction. The purpose of the present study is to determine colloidal and suspended particulate concentrations of Fe, Zn, Cu, Ni, and Mn in sea water. Suspended particulate matter were separated in three different size groups namely (>2.7 microm, <2.7->0.45 microm and <0.45->0.22 microm) by suction filtration using cellulose acetate and nitrate filter membranes. Thereafter to concentrate the solution with colloidal particle <0.22 microm-1.1 nm (0.5 k Nominal Molecular Weight cut-off Limit {NMWL}), the solution obtained from filtration through <0.22 microm, is sequentially passed through the ultra-filtration membranes having pore diameters of 14 nm (300 k NMWL), 3.1 nm (50 k NMWL), 2.2 nm (30 k NMWL), 1.6 nm (10 k NMWL) and 1.1 nm (0.5 k NMWL) by using Stirred Ultra-filtration Cells, operating in concentration mode. The concentration of Fe, Zn, Cu, Ni, and Mn were measured in suspended and dissolved fraction by ion chromatography, ICP-AES and Atomic Absorption Spectrometer. The salinity of the solution in various dissolved fractions of sequential filtration varies between 30.89-34.22 parts per thousand. The maximum concentrations of colloidal Zn, Cu, Ni and Mn in dissolved fraction were in <2.2->1.6 nm fraction. In case of Fe, colloidal fractions <2.2->1.6 nm and <1.6-<1.1 nm shows higher concentration. The concentration of Zn, Cu, Ni and Mn increase with decrease in size in suspended particulate matter, while the reverse is observed in case of Fe. This size separation data that specifies the partitioning of metals between dissolved and suspended solid phases is necessary for developing physically based models of metal transport in aquatic system. 相似文献
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The tunicate species which frequently form part of each other's environment were assorted into groups by the use of an index derived from the corrected geometric mean of joint occurrence of pairs of species following Fager (1957) and Fager and McGowan (1963). The relationships shown in the temperature-salinity-plankton (TSP) diagrams between species and water properties are also used as a basis for classifying the species. Similar relationships have enabled species to be grouped together and consistent differences between one group and another set them apart. 相似文献
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Angelo Pecci Ganapati Patil Orazio Rossi Pierfrancesca Rossi 《Environmental and Ecological Statistics》2010,17(4):473-502
The environmental decision-maker is aware of the increasing difficulties in finding sufficient financial resources for nature
conservation. So he must focus his attention on ecological situations that more than the others merit considering and defending
because of elevated value but also because of risk for their intrinsic characteristics and for human pressure acting on them.
Usually an ecological scientist focuses his attention on the natural patches of the landscape, analyzing their peculiar ecological
traits forgetting that, even if we want to protect some environmental critical situations, this can be done only moving to
the administrative partition of the territory since the central and local environmental stakeholders have primary interest
in providing funds to those involved in those critical situations. The present work shows a methodological approach, consisting
of a set of statistical and geoinformational tools, considering both ecological and socio-demographical indicators. The goal
is not simply to give some general guidelines for environmental policies to the involved stakeholders but focuses more on
finding out which administrative local partitions in a study area are more worthy to receive urgently the priority funds for
biodiversity protection to face critical environmental situations often due to a combination of intrinsic ecological parameters
and external human pressure ones. Obtaining results that cover 5% of the Communes involved in the area seems to be a realistic
result that a decision-maker can support and fund. Methodologically and geospatial data analytically, the investigation offers
interesting challenges for surveillance geoinformatics of hotspot detection and prioritization, because of the presence of
multiple hotspots and multiple sets of multiple indicators. 相似文献
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The present purpose is to provide convenient computational capability and visualizations for preliminary partial or progressive
prioritization based largely on concepts of partial order theory and implemented in R software as illustrated in a context of conservation and sustainable stewardship across landscapes with ecosystem services
as a complex multidimensional domain that must be placed in public and private perspective in pursuit of multi-resource management.
Practical perspective is promoted by graphic visualization with local partial order modeling (LPOM) methods for screening
of settings and scenarios involving interactions of ecosystem elements as evidenced by environmental indicators. ORDIT ordering
and precedence plots arise from ascribed advantage as an outcome of a rating regime. Representative ranks constitute criteria
drawn from the rank distribution for the case in question. Distal data are determined with regard to remediation and retention.
Median mismatches reflect interplay of indicators appearing as isolated instances in plotting patterns. A suggested strategy
to circumvent computational constraints is partitioning the pool of cases into collectives by clustering, pursuing classes
of partitions, and then prioritizing in particular partitions. When prime prospects have been obtained, detailed determinations
can be done with partial ordering procedures involving Hasse diagrams and similarly complex constructs that are difficult
to apply with many cases and/or indicator criteria. 相似文献
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When an environmental sampling objective is to classify all the sample units as contaminated or not, composite sampling with selective retesting can substantially reduce costs by reducing the number of units that require direct analysis. The tradeoff, however, is increased complexity that has its own hidden costs. For this reason, we propose a model for assessing the relative cost, expressed as the ratio of total expected cost with compositing to total expected cost without compositing (initial exhaustive testing). Expressions are derived for the following retesting protocols: (i) exhaustive, (ii) sequential and (iii) binary split. The effects of both false positive and false negative rates are also derived and incorporated. The derived expressions of relative cost are illustrated for a range of values for various cost components that reflect typical costs incurred with hazardous waste site monitoring. Results allow those who are designing sampling plans to evaluate if any of these compositing/retesting protocols will be cost effective for particular applications. 相似文献
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Assessment of daily intake of trace elements by Kakrapar adult population through ingestion pathway 总被引:1,自引:0,他引:1
Akhaya Kumar Patra S. S. Wagh A. K. Jain A. G. Hegde 《Environmental monitoring and assessment》2010,169(1-4):267-272
Concentration of trace elements such as Fe, Cu, Ni, and Zn were measured in cereals, pulses, vegetables, fish, meat, milk, egg, and water samples collected around Kakrapar, Gujarat, India. A wide variation of the trace element concentration was observed among all the dietary matrices. The concentration of Fe is comparatively more in all the dietary matrices. The concentrations of these elements are translated into intake rates through ingestion pathways. Daily intake (milligrams/day) of Fe, Cu, Ni, and Zn by adult population of Kakrapar, Gujarat were 16.5 ± 6.2, 3.3 ± 1.2, 1.8 ± 1.0, and 3.6 ± 1.3, respectively. Dietary sources of Fe, Cu, and Ni by Kakrapar adult population are comparable with RDA. In case of Zn, the daily dietary intake is comparatively lower than that of RDA. 相似文献
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