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1.
Estimation of methane emission from whole waste landfill site using correlation between flux and ground temperature 总被引:1,自引:0,他引:1
Tomonori Ishigaki Masato Yamada Masanao Nagamori Yusaku Ono Yuzo Inoue 《Environmental Geology》2005,48(7):845-853
A methodology to estimate a methane emission in a waste landfill site was developed. The methane flux at a waste landfill
site in summer, autumn, and winter was within the following ranges: from −1.3×10−2 to 16, from −6.4×10−2 to 7.5, and from −1.6×10−3 to 1.5×10−2 g-CH4 m−2 h−1, respectively. In those seasons, the mean methane emission rate and coefficient of variation were 1.1 g-CH4 m−2 h−1 ±290%, 0.57 g-CH4 m−2 h−1 ±347%, and 5.4×10−2 g-CH4 m−2 h−1 ±370%, respectively. These results simultaneously showed that fluctuations of methane emission from the landfill surface
were both of spatial and temporal variability. In each season, an exponential relationship was observed between the methane
flux density and the ground temperature. Total methane emissions were estimated to be 5.7×10−2, 7.1×10−3, and 1.7×10−3 g-CH4 m−2 h−1 in the summer, autumn, and winter surveys, respectively, using a temperature surrogated-kriging method. The results of this
study would improve upon the labor-intensive closed-chamber method, and could be a more practical way to estimate methane
emissions from waste landfills. 相似文献
2.
Sediment and Lower Water Column Oxygen Consumption in the Seasonally Hypoxic Region of the Louisiana Continental Shelf 总被引:1,自引:0,他引:1
We report integrated measurements of sediment oxygen consumption (SOC) and bottom water plankton community respiration rates
(WR) during eight cruises from 2003 to 2007 on the Louisiana continental shelf (LCS) where hypoxia develops annually. Averaged
by cruise, SOC ranged from 3.9 to 25.8 mmol O2 m−2 day−1, whereas WR ranged from 4.1 to 10.8 mmol O2 m−3 day−1. Total below-pycnocline respiration rates ranged from 46.4 to 104.5 mmol O2 m−2 day−1. In general, below-pycnocline respiration showed low variability over a large geographic and temporal range, and exhibited
no clear spatial or inter-annual patterns. SOC was strongly limited by dissolved oxygen (DO) in the overlying water; whereas,
WR was insensitive to low DO, a relationship that may be useful for parameterizing future models. The component measures,
WR and SOC, were similar to most prior measurements, both from the LCS and from other shallow estuarine and coastal environments.
The contribution of SOC to total below-pycnocline respiration averaged 20 ± 4%, a finding that differs from several prior
LCS studies, but one that was well supported from the broader estuarine and oceanic literature. The data reported here add
substantially to those available for the LCS, thus helping to better understand oxygen dynamics on the LCS. 相似文献
3.
Zhongmei Wang Lijun Zhu Ruidong Yang Shengyuan Yang Jianping Ding Genlan Yang 《中国地球化学学报》2012,31(2):195-203
The karst groundwater system is extremely vulnerable and easily contaminated by human activities.To understand the spatial distribution of contaminants in the groundwater of karst urban areas and contributors to the contamination,this paper employs the spatial information statistics analysis theory and method to analyze the karst groundwater environment in Guiyang City.Based on the karst ground water quality data detected in 61 detection points of the research area in the last three years,we made Kriging evaluation isoline map with some ions in the karst groundwater,such as SO4 2-,Fe 3+,Mn 2+and F -,analyzed and evaluated the spatial distribution,extension and variation of four types of ions on the basis of this isoline map.The results of the analysis show that the anomaly areas of SO4 2-,Fe 3+,Mn 2+,Fand other ions are mainly located in Baba’ao,Mawangmiao and Sanqiao in northwestern Gui- yang City as well as in its downtown area by reasons of the original non-point source pollution and the contamination caused by human activities(industrial and domestic pollution). 相似文献
4.
Studying spatial and temporal variation of soil loss is of great importance because of global environmental concerns. Understanding
the spatial distribution of soil erosion and deposition in the high-cold steppe is important for designing soil and water
conservation measures. Measured 137Cs losses (Bq m−2) from long-term high altitude (4,000 m above sea level) watershed plots on the Qinghai–Tibet plateau and derived soil erosion
estimates (Mg ha−1 year−1) were significantly correlated to directly measured soil losses from the same plots, over the same period (1963–2005). The
local reference inventory was estimated to be 2,468 Bq m−2. The result of analyzing 137Cs distribution and its intensity in the soil profiles in this area shows similarities to 137Cs distribution in other areas. 137Cs is basically distributed in the topsoil layer of 0–0.3 m. Soil erosions vary greatly in the entire sampled area, ranging
from 5.5 to 23 Mg ha−1 year−1, with an average of 16.5 Mg ha−1 year−1 which is a moderate rate of erosion. 相似文献
5.
6.
Geographical information system (GIS) technology was used to investigate NO3
− concentration of groundwater in the Zhangye Basin, Northwest China. Thematic information and NO3
− data of groundwater from the Zhangye Basin were analyzed in a GIS environment to study the extent and variation of NO3
− concentration and to establish spatial relationships with corresponding land use types. About 38.8% of groundwater samples
showed NO3
− concentration above the human affected value (13 mg/l NO3
−), while more than 10.2% exceeded the maximum acceptable level (50 mg/l NO3
−) according to WHO regulations. The spatial distribution of NO3
− of groundwater in the Zhangye Basin showed an obvious character of zonation; the high NO3
− concentration was mainly located in the city seat areas, and Zhangye City was the high-value center. The probability of over
90% for NO3
− concentration exceeding 13 mg/l was found in urban seat areas. The spatial analyses indicated that groundwater contamination
by NO3
− was closely related to one specific land use class, the urban. The NO3
− concentration of groundwater under urban was significantly higher than that under irrigation land or sand dune. Most of the
unacceptable NO3
− levels were found in groundwater samples assigned to urban area, but a few were also found allotted to irrigation land class.
Therefore, urban source was considered the principal source of NO3
− contamination of groundwater in the Zhangye Basin, while irrigation land source was still a possible source of NO3
− contamination. 相似文献
7.
In situ x-ray data on molar volumes of periclase and tungsten have been collected over the temperature range from 300 K to melting.
We determine the temperature by combining the technique of spectroradiometry and electrical resistance wire heating. The thermal
expansion (α) of periclase between 300 and 3100 K is given by α=2.6025 10−5+1.3535 10−8 T+6.5687 10−3 T−1−1.8281 T−2.
For tungsten, we have (300 to 3600 K) α=7.862 10−6+6.392 10−9 T.
The data at 298 K for periclase is: molar volume 11.246 (0.031) cm3, α=3.15 (0.07) 10−5 K−1, and for tungsten: molar volume 9.55 cm3, α=9.77 (10.08) 10−6 K−1.
Received: July 18, 1996 / Revised, accepted: February 14, 1997 相似文献
8.
Heavy metal concentrations and their possible sources in paddy soils of a modern agricultural zone,southeastern China 总被引:5,自引:0,他引:5
In a typical modern agricultural Zone of southeastern China, Haining City, 224 topsoil samples were collected from paddy fields
to measure the total concentrations of copper (Cu), lead (Pb), zinc (Zn), cadmium (Cd), chromium (Cr), mercury (Hg), arsenic
(As) and cobalt (Co). The total concentrations ranged from 15.30 to 78.40 mg kg−1 for Cu, 20.10 to 41.40 mg kg−1 for Pb, 54.98 to 224.4 mg kg−1 for Zn, 0.04 to 0.24 mg kg−1 for Cd, 54.90 to 197.1 mg kg−1 for Cr, 0.03 to 0.61 mg kg−1 for Hg, 3.44 to 15.28 mg kg−1 for As, and 7.17 to 19.00 mg kg−1 for Co. Chemometric techniques and geostatistics were utilized to quantify their spatial characteristics and define their
possible sources. All eight metals had a moderate spatial dependency except that Pb had a strong spatial dependency. Both
factor analysis and cluster analysis successfully classified the eight metals into three groups or subgroups, the first group
included Cu, Zn and Cr, the second group included Cd, As and Co, and the last group included Pb and Hg. The Cu, Zn and Cr
concentrations in majority samples were higher than their local background concentrations and they were highly correlated
(r > 0.80), indicating that they had similar pollution source and anthropic factor controlled their spatial distribution; the
Cd, As and Co concentrations in majority samples were lower than their local background concentrations, indicating that the
source of these elements was mainly controlled by natural factors; the mean concentration of Pb exhibited generally low level,
close to its local background concentration, the Hg concentration in about half of samples was higher than its local background
concentration, and they were poor correlated with the other metals, indicating that the source of Pb and Hg was common controlled
by natural factor and anthropic factor. 相似文献
9.
The production of organic matter and calcium carbonate by a dense population of the brittle star Acrocnida brachiata (Echinodermata) was calculated using demographic structure, population density, and relations between the size (disk diameter)
and the ash-free dry weight (AFDW) or the calcimass. During a 2-year survey in the Bay of Seine (Eastern English Channel,
France), organic production varied from 29 to 50 gAFDW m−2 year−1 and CaCO3 production from 69 to 104 gCaCO3 m−2 year−1. Respiration was estimated between 1.7 and 2.0 molCO2 m−2 year−1. Using the molar ratio (ψ) of CO2 released: CaCO3 precipitated, this biogenic precipitation of calcium carbonate would result in an additional release between 0.5 and 0.7 molCO2 m−2 year−1 that represented 23% and 26% of total CO2 fluxes (sum of calcification and respiration). The results of the present study suggest that calcification in temperate shallow
environments should be considered as a significant source of CO2 to seawater and thus a potential source of CO2 to the atmosphere, emphasizing the important role of the biomineralization (estimated here) and dissolution (endoskeletons
of dead individuals) in the carbon budget of temperate coastal ecosystems. 相似文献
10.
11.
Elastic wave velocities for dense (99.8% of theoretical density) isotropic polycrystalline specimens of synthetic pyrope (Mg3Al2Si3O12) were measured to 1,000 K at 300 MPa by the phase comparison method of ultrasonic interferometry in an internally heated
gas-medium apparatus. The temperature derivatives of the elastic moduli [(∂Ks/∂T)
P
= −19.3(4); (∂G/∂T)
P
= −10.4(2) MPa K−1] measured in this study are consistent with previous acoustic measurements on both synthetic polycrystalline pyrope in a
DIA-type cubic anvil apparatus (Gwanmesia et al. in Phys Earth Planet Inter 155:179–190, 2006) and on a natural single crystal by the rectangular parallelepiped resonance (RPR; Suzuki and Anderson in J Phys Earth 31:125–138,
1983) method but |(∂Ks/∂T)
P
| is significantly larger than from a Brillouin spectroscopy study of single-crystal pyrope (Sinogeikin and Bass in Phys Earth
Planet Inter 203:549–555, 2002). Alternative approaches to the retrieval of mixed derivatives of the elastic moduli from joint analysis of data from this
study and from the solid-medium data of Gwanmesia et al. in Phys Earth Planet Inter 155:179–190 (2006) yield ∂2
G/∂P∂T = [0.07(12), 0.20(14)] × 10−3 K−1 and ∂2
K
S
/∂P∂T = [−0.20(24), 0.22(26)] × 10−3 K−1, both of order 10−4 K−1 and not significantly different from zero. More robust inference of the mixed derivatives will require solid-medium acoustic
measurements of precision significantly better than 1%. 相似文献
12.
Mohsen Jalali 《Environmental Geology》2007,53(2):365-374
Phosphorus (P) application in excess of plant requirement may result in contamination of drinking water and eutrophication
of surface water bodies. The phosphorous buffer capacity (PBC) of soil is important in plant nutrition and is an important
soil property in the determination of the P release potential of soils. Phosphorus sorption greatly affects both plant nutrition
and environmental pollution. For better and accurate P fertilizer recommendations, it is necessary to quantify P sorption.
This study was conducted to investigate available P and P sorption by calcareous soils in a semi-arid region of Hamadan, western
Iran. The soil samples were mainly from cultivated land. Olsen’s biocarbonate extractable P (Olsen P) varied among soils and
ranged from 10 to 80 mg kg−1 with a mean of 36 mg kg−1. Half of the soils had an Olsen P > 40 mg kg−1 and >70% of them had a concentration >20 mg kg−1, whereas the critical concentration for most crops is <15 mg P kg−1. Greater average Olsen P in soils occurred under garlic (56 mg kg−1) and potato (44 kg kg−1) fields than in dry-land wheat farming (24 mg kg−1), pasture (30 mg kg−1), and wheat (24 mg P kg−1) fields. A marked increase in fertilizer P rates applied to agricultural soils has caused P to be accumulated in the surface
soil. Phosphate sorption curves were well fitted to the Freundlich equation. The standard P requirement (SPR) of soils, defined
as the amount of P sorbed at an equilibrium concentration of 0.2 mg l−1 ranged from 4 to 102 mg kg−1. Phosphorus buffer capacity was relatively high and varied from 16 to 123 l kg−1 with an average of 58 l kg−1. In areas of intensive crop production, continual P applications as P fertilizer and farmyard manure have been used at levels
exceeding crop requirements. Surface soil accumulations of P are high enough that loss of P in surface runoff and a high risk
for P transfer into groundwater have become priority management concerns. 相似文献
13.
Total nitrogen (TN), total phosphorus (TP), and total suspended solids (TSS) loadings [log (kg ha−1 yr−1)] were regressed against seagrass depth limits (percent of depth-limit targets) to back-predict the load limits or allocations
(kg ha−1 yr−1 or kg yr−1) necessary to meet targeted seagrass depth limits in the Indian River and Banana River (IRBR) lagoons, Florida. Because the
load allocations can be applied as total maximum daily loads (TMDL) for the IRBR (U.S. Environmental Protection Agency mandate),
the method and results are developed and presented toward that end. The regression analyses indicate that the range of surface-discharge
load limits (nonpoint + point source), per watershed area, required to achieve the desired depth limits for seagrass in the
IRBR are approximately 2.4–3.2 kg ha−1 yr−1 TN, 0.41–0.64 kg ha−1 yr−1 TP, and 48–64 kg ha−1 yr−1 TSS. This simple regression method may have application to other shallow estuarine lagoons or bays where seagrass growth
is limited by light and water transparency, water transparency is strongly affected by watershed pollutant loadings, water
residence times are sufficiently long to allow seagrass coverage to respond to and covary with total load inputs, and multiyear
monitoring has yielded sufficient variability in both pollutant loadings and seagrass coverages to develop a statistically
meaningful relationship. 相似文献
14.
We developed light requirements for eelgrass in the Pacific Northwest, USA, to evaluate the effects of short- and long-term
reductions in irradiance reaching eelgrass, especially related to turbidity and overwater structures. Photosynthesis-irradiance
experiments and depth distribution field studies indicated that eelgrass productivity was maximum at a photosynthetic photon
flux density (PPFD) of about 350–550 μmol quanta m−2 s−1. Winter plants had approximately threefold greater net apparent primary productivity rate at the same irradiance as summer
plants. Growth studies using artificial shading as well as field monitoring of light and eelgrass growth indicated that long-term
survival required at least 3 mol quanta m−2 day−1 on average during spring and summer (i.e., May-September), and that growth was saturated above about 7 mol quanta m−2 day−1. We conclude that non-light-limited growth of eelgrass in the Pacific Northwest requires an average of at least 7 mol quanta
m−2 day−1 during spring and summer and that long-term survival requires a minimum average of 3 mol quanta m−2 day−1. 相似文献
15.
Hydraulic properties of the crystalline basement 总被引:1,自引:1,他引:1
Hydraulic tests in boreholes, up to 4.5 km deep, drilled into continental crystalline basement revealed hydraulic conductivity
(K) values that range over nine log-units from 10−13−10−4 m s−1. However, K values for fractured basement to about 1 km depth are typically restricted to the range from 10−8 to 10−6 m s−1. New data from an extended injection test at the KTB research site (part of the Continental Deep Drilling Program in Germany)
at 4 km depth provide K=5 10−8 m s−1. The summarized K-data show a very strong dependence on lithology and on the local deformation history of a particular area. In highly fractured
regions, granite tends to be more pervious than gneiss. The fracture porosity is generally saturated with Na–Cl or Ca–Na–Cl
type waters with salinities ranging from <1 to >100 g L−1. The basement permeability is well within the conditions for advective fluid and heat transport. Consequently, fluid pressure
is hydrostatic and a Darcy flow mechanism is possible to a great depth. Topography-related hydraulic gradients in moderately
conductive basement may result in characteristic advective flow rates of up to 100 L a−1 m−2 and lead to significant advective heat and solute transfer in the upper brittle crust.
An erratum to this article can be found at 相似文献
16.
J. Zhang I. Martinez F. Guyot P. Gillet S. K. Saxena 《Physics and Chemistry of Minerals》1997,24(2):122-130
P–V–T measurements on magnesite MgCO3 have been carried out at high pressure and high temperature up to 8.6 GPa and 1285 K, using a DIA-type, cubic-anvil apparatus
(SAM-85) in conjunction with in situ synchrotron X-ray powder diffraction. Precise volumes are obtained by the use of data collected above 873 K on heating and
in the entire cooling cycle to minimize non-hydrostatic stress. From these data, the equation-of-state parameters are derived
from various approaches based on the Birch-Murnaghan equation of state and on the relevant thermodynamic relations. With K′0 fixed at 4, we obtain K0=103(1) GPa, α(K−1)=3.15(17)×10−5 +2.32(28)×10−8 T, (∂KT/∂T)P=−0.021(2) GPaK−1, (dα/∂P)T=−1.81×10−6 GPa−1K−1 and (∂KT/∂T)V= −0.007(1) GPaK−1; whereas the third-order Birch-Murnaghan equation of state with K′0 as an adjustable parameter yields the following values: K0=108(3) GPa, K′0=2.33(94), α(K−1)=3.08(16)×10−5+2.05(27) ×10−8 T, (∂KT/∂T)P=−0.017(1) GPaK−1, (dα/∂P)T= −1.41×10−6 GPa−1K−1 and (∂KT/∂T)V=−0.008(1) GPaK−1. Within the investigated P–T range, thermal pressure for magnesite increases linearly with temperature and is pressure (or
volume) dependent. The present measurements of room-temperature bulk modulus, of its pressure derivative, and of the extrapolated
zero-pressure volumes at high temperatures, are in agreement with previous single-crystal study and ultrasonic measurements,
whereas (∂KT/∂T)P, (∂α/∂P)T and (∂KT/∂T)V are determined for the first time in this compound. Using this new equation of state, thermodynamic calculations for the
reactions (1) magnesite=periclase+CO2 and (2) magnesite+enstatite=forsterite+CO2 are consistent with existing experimental phase equilibrium data.
Received September 28, 1995/Revised, accepted May 22, 1996 相似文献
17.
M. M. Saç E. Yumurtaci G. Yener B. Camgöz A. Uğur B. Özden 《Environmental Geology》2008,55(3):477-483
Gediz Basin is one of the regions where intense agricultural activities take place in Western Turkey. Erosion and soil degradation
have long been causing serious problems to cultivated fields in the basin. This work describes the application of two different
137Cs models for estimating soil erosion rates in cultivated sites of the region. Soil samples were collected from five distinct
cultivated regions subject to soil erosion. The variations of 137Cs concentrations with depth in soil profiles were investigated. Soil loss rates were calculated from 137Cs inventories of the samples using both proportional model (PM) and simplified mass balance model (SMBM). When PM was used,
erosion and deposition rates varied from −15 to −28 t ha−1 year−1 and from +5 to +41 t ha−1 year−1, respectively; they varied from −16 to −33 t ha−1 year−1 and from +5 to +55 t ha−1 year−1 with SMBM. A good agreement was observed between the results of two models up to 30 t ha−1 year−1 soil loss and gain in the study area. Ulukent, a small representative agricultural field, was selected to compare the present
data of 137Cs techniques with the results obtained by universal soil loss equation (USLE) applied in the area before. 相似文献
18.
Katja Etzel Artur Benisek Edgar Dachs Lado Cemič 《Physics and Chemistry of Minerals》2007,34(10):733-746
The unite cell parameters and heat capacities of a series of synthetic clinopyroxenes on the join Ca-Tschermak (CaTs)−diopside
(Di) were measured using X-ray powder diffraction and calorimetric methods, respectively. The volume of mixing at 298 K shows
a negative asymmetric deviation from ideality. A two-parameter Margules fit to the data yields W
CaTs−Di
V
= −0.29 ± 0.11 cm3 mol−1 and W
Di−CaTs
V
= −1.14 ± 0.14 cm3 mol−1. Heat capacities were determined between 5 and 923 K by heat-pulse at 5−302 K and differential-scanning calorimetry at 143−923 K.
The precision of the low and high temperature C
p
data is better than ±1%. Polynomials of the form C
p
= a + bT
−1/2 + cT
−2 + dT
−3 were fitted to the C
p
data in the temperature range between 250 and 925 K. Thermal entropy values [S
298 − S
0] and [S
900 −S
0] as well as enthalpies [H
298 − H
0] and [H
900 − H
0] were calculated for all members of the solid solution series. No significant deviation from ideal mixing behavior was observed. 相似文献
19.
Daily and annual integrated rates of primary productivity and community respiration were calculated using physiological parameters
measured in oxygen-based photosynthesis-irradiance (P-I) incubations at 8 stations throughout central and western Long Island
Sound (cwLIS) during the summer and autumn of 2002 and 2003 and the late spring of 2003. Each calculation takes into account
actual variations in incident irradiance over the day and underwater irradiance and standing stock with depth. Annual peak
rates, ±95% confidence interval of propagated uncertainty in each measurement, of gross primary production (GPP, 1,730±610
mmol O2 m−2 d−1), community respiration (Rc, 1,660±270 mmol O2 m−2 d−1), and net community production (NCP, 1,160±1,100 mmol O2 m−2 d−1) occurred during summer at the western end of the Sound. Lowest rates of GPP (4±11 mmol O2 m−2 d−1), Rc (−50±300 mmol O2 m−2 d−1), and NCP (−1,250±270 mmol O2 m−2 d−1) occurred during late autumn-early winter at the outer sampled stations. These large ranges in rates of GPP, Rc, and NCP throughout the photic zone of cwLIS are attributed to seasonal and spatial variability. Algal respiration (Ra) was estimated to consume an average of 5% to 52% of GPP, using a literature-based ratio of Ra:Rc. From this range, we established that the estimated Ra accounts for approximately half of GPP, and was used to estimate daily net primary production (NPP), which ranged from 2
to 870 mmol O2 m−2 d−1 throughout cwLIS during the study. Annual NPP averaged 40±8 mol O2 m−2 yr−1 for all sampled stations, which more than doubled along the main axis of the Sound, from 32±14 mol O2 m−2 yr−1 at an eastern station to 82±25 mol O2 m−2 yr−1 at the western-most station. These spatial gradients in productivity parallel nitrogen loads along the main axis of the Sound.
Daily integrals of productivity were used to test and formulate a simple, robust biomass-light model for the prediction of
phytoplankton production in Long Island Sound, and the slope of the relationship was consistent with reports for other systems. 相似文献
20.
Chalcedony is a spatial arrangement of hydroxylated nanometre-sized α-quartz (SiO2) crystallites that are often found in association with the silica mineral moganite (SiO2). A supplementary Raman band at 501 cm−1 in the chalcedony spectrum, attributed to moganite, has been used for the evaluation of the quartz/moganite ratio in silica
rocks. Its frequency lies at 503 cm−1 in sedimentary chalcedony, representing a 2 cm−1 difference with its position in pure moganite. We present a study of the 503 cm−1 band’s behaviour upon heat treatment, showing its gradual disappearance upon heating to temperatures above 300 °C. Infrared
spectroscopic measurements of the silanole (SiOH) content in the samples as a function of annealing temperature show a good
correlation between the disappearance of the 503 cm−1 Raman band and the decrease of structural hydroxyl. Thermogravimetric analyses reveal a significant weight loss that can
be correlated with the decreasing of this Raman band. X-ray powder diffraction data suggest the moganite content in the samples
to remain stable. We propose therefore the existence of a hitherto unknown Raman band at 503 cm−1 in chalcedony, assigned to ‘free’ Si–O vibrations of non-bridging Si–OH that oscillate with a higher natural frequency than
bridging Si–O–Si (at 464 cm−1). A similar phenomenon was recently observed in the infrared spectra of chalcedony. The position of this Si–OH-related band
is nearly the same as the Raman moganite band and the two bands may interfere. The actually observed Raman band in silica
rocks might therefore be a convolution of a silanole and a moganite vibration. These findings have broad implications for
future Raman spectroscopic studies of moganite, for the assessment of the quartz/moganite ratio, using this band, must take
into account the contribution from silanole that are present in chalcedony and moganite. 相似文献