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471.
The presence of natural estrogen hormones as trace concentrations in the environment has been reported by many researchers
and is of growing concern due to its possible adverse effects on the ecosystem. In this study, municipal biosolids, poultry
manure (PM) and cow manure (CM), and spent mushroom compost (SMC) were analyzed for the presence of seven estrogen hormones.
17α-estradiol, 17β-estradiol, 17α-dihydroequilin, and estrone were detected in the sampled biosolids and manures at concentrations
ranging from 6 to 462 ng/g of dry solids. 17α-estradiol, 17β-estradiol, and estrone were also detected in SMC at concentrations
ranging from 4 to 28 ng/g of dry solids. Desorption experiments were simulated in the laboratory using deionized water (milli-Q),
and the aqueous phase was examined for the presence of estrogen hormones to determine their desorption potential. Very low
desorption of 0.4% and 0.2% estrogen hormones was observed from municipal biosolids and SMC, respectively. An estimate of
total estrogen contribution from different solid waste sources is reported. Animal manures (PM and CM) contribute to a significant
load of estrogen hormones in the natural environment. 相似文献
472.
The objective of this study is to assess the risk of insufficient water supply posed by high-turbidity water. Several phenomena
can pose risks to the sufficiency of a water supply; this study concerns risks to water treatment plants from particular properties
of rainfall and raw water turbidity. High-turbidity water can impede water treatment plant operations; rainfall properties
can influence the degree of soil erosion. Thus, water turbidity relates to rainfall characteristics. Exceedance probabilities
are presented for different rainfall intensities and turbidities of water. When the turbidity of raw water is higher than
5,000 NTU, it can cause operational problems for a water treatment plant. Calculations show that the turbidity of raw water
at the Ban-Sin water treatment plant will be higher than 5,000 NTU if the rainfall intensity is larger than 165 mm/day. The
exceedance probability of high turbidity (turbidity >5,000 NTU) in the Ban-Sin water treatment plant is larger than 10%. When
any water treatment plant cannot work regularly, its ability to supply water to its customers is at risk. 相似文献
473.
As facile “environmental media”, the outdoor dust may reflect the changes of contaminants in environment more promptly. In
the present study, selected organochlorine contaminants (OCs) include hexachlorocyclohexanes (HCHs), dichlorodiphenyltrichloroethanes
(DDTs), hexachlorobenzene (HCB), and pentachlorobenzene (PeCB) were detected in 20 outdoor dust samples collected from Xinxiang
City. The concentrations of ΣHCHs, ΣDDTs, HCB, and PeCB in dust were in the range of 0.18–5.05 ng/g dry weight, 0.44–13.50 ng/g
dry weight, 0.13–51.61 ng/g dry weight and ND-0.74 ng/g dry weight, respectively. Long-range transport, historical use, and
recent impact of impure pesticides might be the main sources of OCs in the outdoor dust. The results of this study indicated
that impure pesticide application maybe an important source of DDTs and HCB in the environment. 相似文献
474.
Sakizadeh M Esmaeili Sari A Abdoli A Bahramifar N Hashemi SH 《Environmental monitoring and assessment》2012,184(5):3231-3237
The Anzali Wetland is one of the most important ecosystems in the north of Iran, and parts of it were registered as a Ramsar
site in 1975. However, even though, due to many problems, including eutrophication produced by inflow of excess nutrients
and organic materials, the wetland was also listed on the Montreux Record indicating the need to take urgent remedial action.
This study was conducted to study the levels of polychlorinated biphenyls (PCBs) and total mercury (THg) in two fish species
(Esox lucius and Carassius auratus) as bio-indicators of the ecosystem condition in eastern part of Anzali Wetland. The sampling was carried out in six different
periods between years 2009 and 2010. The results showed that the amounts of PCBs in the muscle of northern pike were below
the detection limit of gas chromatography, whereas the average concentration in goldfish was 0.449 mg/kg wet weight. Some
possible reasons for the higher levels of PCBs in goldfish in comparison with pike have been discussed. No significant (p < 0.05) correlation was observed between PCBs and biological factors (weight, length, lipid content) for both species. On
the other hand, the mean concentration of THg in the muscle of pike and goldfish were 182.22 and 75.27 ng/g dry weight, respectively.
Although these concentrations were below US-EPA criterion for human consumption (0.3 mg/kg), it pointed up a significant deterioration
of the ecosystem condition during the past years. Finally, statistical analysis revealed a significant correlation between
THg with weight and an insignificant correlation with length for pike specimens. 相似文献
475.
Both the net primary productivity (NPP) and the normalized difference vegetation index (NDVI) are commonly used as indicators
to characterize vegetation vigor, and NDVI has been used as a surrogate estimator of NPP in some cases. To evaluate the reliability
of such surrogation, here we examined the quantitative difference between NPP and NDVI in their outcomes of vegetation vigor
assessment at a landscape scale. Using Landsat ETM+ data and a process model, the Boreal Ecosystem Productivity Simulator,
NPP distribution was mapped at a resolution of 90 m, and total NDVI during the growing season was calculated in Heihe River
Basin, Northwest China in 2002. The results from a comparison between the NPP and NDVI classification maps show that there
existed a substantial difference in terms of both area and spatial distribution between the assessment outcomes of these two
indicators, despite that they are strongly correlated. The degree of difference can be influenced by assessment schemes, as
well as the type of vegetation and ecozone. Overall, NDVI is not a good surrogate of NPP as the indicators of vegetation vigor
assessment in the study area. Nonetheless, NDVI could serve as a fairish surrogate indicator under the condition that the
target region has low vegetation cover and the assessment has relatively coarse classification schemes (i.e., the class number
is small). It is suggested that the use of NPP and NDVI should be carefully selected in landscape assessment. Their differences
need to be further evaluated across geographic areas and biomes. 相似文献
476.
This article sets out to analyse how and to what degree land use is linked to the physical characteristics of the territory
itself, and the way in which changes in land use are determined by agricultural and socio-demographic dynamics. The study
was conducted within the territorial boundaries of five municipalities surrounding Lake Trasimeno and refers to the periods
1977–2000 for land use and 1971–2001 for socio-demography data. The use of environmental, social, economic and agricultural
indicators demonstrates how a mix of various indicators are useful for monitoring the changes which took place. It also shows
the powerful influence that socio-demographic factors exert upon land use and landscape change. 相似文献
477.
Voss KA Pohlman A Viswanathan S Gibson D Purohit J 《Environmental monitoring and assessment》2012,184(3):1603-1616
Environmental agencies across the United States have searched for adequate methods to assess anthropogenic impacts on the
environment. Biological assessments, which compare the taxonomic composition of an aquatic assemblage to relevant biocriteria,
have surfaced as an effective method to assess the ecological integrity of US waterbodies. In this study, bioassessment data
were collected and analyzed in conjunction with physical habitat and chemical stressor data for streams and rivers within
the San Diego basin from 1998 through 2005. Physical stressors such as sediment loading, riparian destruction, and in-stream
habitat homogenization affect many locations in the region. However, physical habitat measures alone were found to frequently
overestimate the biological integrity of streams in the region. Many sites within the San Diego Basin, although unaffected
by physical stressors, continue to exhibit low biological integrity scores. Sites with low biological integrity tend to possess
higher specific conductance and salinity compared to sites with high biological integrity. We suggest that one possible reason
for these differences is the source water used for municipal purposes. 相似文献
478.
Spatial and seasonal distribution of nitrogen in marsh soils of a typical floodplain wetland in Northeast China 总被引:3,自引:0,他引:3
Bai J Wang Q Deng W Gao H Tao W Xiao R 《Environmental monitoring and assessment》2012,184(3):1253-1263
Horizontal and profile distributions of nitrogen in marsh soils in different seasons were studied in a typical site within
the Erbaifangzi wetland in Northeast China. Results showed that there was higher spatial heterogeneity for nitrate nitrogen
(NO3--_{3}^{-}-N) and ammonium nitrogen (NH4+_{4}^{+}–N), as well as available nitrogen (AN), in surface soils in July compared to that in September. Relative to July, the mean
nitrogen contents in surface soils were slightly higher in September; however, in November, soils contained significantly
lower NO3--_{3}^{-}-N and NH4+_{4}^{+}–N, higher AN, organic nitrogen (Org-N), and total nitrogen (TN). Except for mineral nitrogen, no significant differences
were observed between Org-N and TN contents in September and November. Nitrogen contents generally declined exponentially
with depth along soil profiles in three sampling dates (July, September, and November), except for a significant accumulation
peak of NO3--_{3}^{-}-N at the 20–30 cm depth in September. However, NH4+_{4}^{+}–N contents showed a vertical alternation of “increasing and decreasing” in both July and September, while nearly kept constant
with depth in November. The depth ranking of nitrogen showed the shallowest distribution for AN, followed by Org-N and TN,
while deeper distributions for NO3--_{3}^{-}-N and NH4+_{4}^{+}–N. TN, Org-N, and AN were significantly correlated with soil organic matter and total phosphorus. Soil pH values were significantly
correlated with TN and AN contents in surface soils. Clay contents showed significant correlations with nitrogen contents
except for NO3--_{3}^{-}-N in surface soils and NH4+_{4}^{+}–N in profile soils. However, soil moisture was not significantly correlated with nitrogen contents among all soil samples. 相似文献
479.
Mehmet Sinan Bilgili Gamze Varank Elif Sekman Selin Top Didem Özçimen Remziye Yazıcı 《Environmental Modeling and Assessment》2012,17(3):289-300
Since phenols and phenolic compounds in many industrial wastewaters are toxic organic contaminants for humans and aquatic
life, to remove these compounds via the most efficient way is very important for environmental remediation treatment. In this
context, almost all of the isotherm models (Freundlich, Langmuir, Temkin, Redlich–Peterson, Sips, and Khan) for adsorption
in the literature were applied to explain the adsorption mechanism of 4-chlorophenol on activated carbon in this study. Also
theoretical modeling data were obtained using model equations; interpolation and analysis of variance were made to compare
data by using statistics software. In addition, the thermodynamic and kinetic studies for adsorption mechanism were included
in the article. The adsorption of 4-chlorophenol on activated carbon fits well to the pseudo-first-order kinetic model than
the pseudo-second-order, intraparticular diffusion and Bangham models. It is also indicated that 4-chlorophenol adsorption
by granular activated carbon would be attributed to a type of transition between physical and chemical adsorption rather than
a pure physical or chemical adsorption process. As a result, an environmental remediation problem and the adsorption mechanism
on activated carbon that can be regarded as a solution to this problem are described and explained using the mathematical
models and calculations in this study. 相似文献
480.
de Andrade Brito I Arruda Freire C Yamamoto FY Silva de Assis HC Rodrigues Souza-Bastos L Cestari MM de Castilhos Ghisi N Prodocimo V Filipak Neto F de Oliveira Ribeiro CA 《Journal of environmental monitoring : JEM》2012,14(2):615-625
Paraíba do Sul River is located at a very densely inhabited region of Brazil crossing the three most industrialized states of the country (S?o Paulo, Minas Gerais and Rio de Janeiro states). As a result, industrial and farming residues as well as urban sewage are frequently disposed without appropriate treatment. The current study aimed at investigating the water quality in three reservoirs along the Paraíba do Sul River (Ilha dos Pombos, Santa Cecília and Santa Branca), through physiological, morphological, biochemical, and genetic biomarkers. The bioindicator chosen was the catfish Pimelodus maculatus, sampled during the dry (June 2008) and rainy (February 2009) seasons. Also, some water physicochemical parameters were analyzed from the sampling sites, but displayed no alterations according to the Brazilian Agency for Water Quality Legislation. Branchial carbonic anhydrase activity was inhibited in the dry season, while renal carbonic anhydrase activity was inhibited in the rainy season in the Santa Branca reservoir, indicating disturbance of osmoregulatory and acid-base regulation processes. Histopathological alterations were observed in the gills (neoplasic and tissue hyperplasia processes) and liver (necrosis), indicating serious damage to the functional integrity of these organs. A high incidence of melanomacrophage centers was observed in the liver, suggesting an intense immune response in all reservoirs. Acetylcholinesterase and catalase activity showed also differences corroborating some morphological results. Likewise, the induction of the micronucleus and DNA damage indicate genotoxicity, but mainly in the Santa Branca reservoir. Thus, the health status of P. maculatus warrants caution in the use of the water from the 3 reservoirs for direct human consumption, particularly after the accidental spill of endosulfan in November 2008, three months before the rainy season sampling. 相似文献