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1.
Ejechi BO Olobaniyi SB Ogban FE Ugbe FC 《Environmental monitoring and assessment》2007,128(1-3):495-501
The physical (pH, Dissolved Solids, Dissolved Oxygen, conductivity, water depth temperature) and bacteriological (Total coliforms,
Faecal coliforms) characteristics of 22 hand-dug wells in oil-rich Niger Delta of Nigeria were investigated. All coliforms
counts (Log10 MPN/100 ml) varied from well to well ranging from 0 to 6.0 although faecal coliform counts were markedly lower (0–3.5 vs
1.0–6.0). When both seasons were compared, faecal coliform counts were significantly higher (t test; P < 0.05) during the wet season whereas no significant difference was observed in respect of total coliforms. Unlike the total
coliforms, faecal coliform counts increased in wells close to septic tanks during the wet season. Although a declining trend
was observed during the wet season, the values of the physical parameters were within WHO limits. The pH was slightly acidic
(Mean ± SD: dry season, 6.04 ± 0.66; wet, 6.43 ± 0.62) and may be attributed to emissions from gas flaring and petroleum refining
activities, which is common in the area. While the total coliform counts reflected the unsanitary habits of the well users,
the detection of faecal coliforms exceeding recommended numbers in 63% of the wells render them unfit for domestic use. The
public health implication is obvious considering the increasing number of people using the wells due to the rapid urbanization
of the oil-rich region. 相似文献
2.
The present study was aimed to make an assessment of health risk due to pollution and human pathogenic bacteria associated
with the recreational and drinking water sources in twin densely populated holy Indian cities Ayodhya and Faizabad. Though
physicochemical studies revealed that the water available in the area is under recommended limits for human use, it is unsafe
on account of poor microbiological quality of surface and ground water in the region. The most probable number (MPN) test
results revealed the preponderance of ≥2,400 total coliforms (TC) (100 ml) − 1 in river, pond, dug well and kund waters. Contrary to that, 94% tube wells, 32% hand pumps and 25% piped supply water were
under safe limits having <3 TC (100 ml) − 1. The shallow depth (~40 ft), water logging and presence of septic tanks in the near vicinity are the possible reasons of
poor microbial quality of hand pump drinking water. The municipal supply water passes along sewage line where loose connections
and/or cracks in pipe lead to mixing and contamination. The significant best quality of tube well water evident from the absence
of TC could be attributed to the depth of well ≥150 ft and usually their location away from the habitation. A total of 263
bacteria from 186 water samples were isolated, and at least five genera of enteric bacteria from various water sources were
identified morphologically and biochemically as Escherichia coli, Klebsiella sp., Enterobacter sp., Shigella sp. and Salmonella sp. The serotyping of 72 E. coli and 36 Salmonella sp. revealed 51 as E. coli O157 and 20 as Salmonella sp. The presence of enteric pathogens in water sources pose threat to human health and therefore call for immediate remedial
measures. 相似文献
3.
Water quality assessment: surface water sources used for drinking and irrigation in Zaria,Nigeria are a public health hazard 总被引:1,自引:0,他引:1
Chigor VN Umoh VJ Okuofu CA Ameh JB Igbinosa EO Okoh AI 《Environmental monitoring and assessment》2012,184(5):3389-3400
We assessed the quality and pollution status of source surface waters in Zaria, Nigeria by monitoring the nature, cause and
extent of pollution in Samaru stream, Kubanni River and Kubanni dam over a period of 10 months, between March and December
2002. A total of 228 water samples was collected from 12 sites and analysed for a total of ten physicochemical and one bacteriological
quality indicators, using standard methods. Aesthetic water quality impairment parameters were also observed. The mean values
of most water quality parameters were significantly higher (P < 0.05) in both the stream and river than in the dam. There was no significant correlation between faecal coliform counts
(FCC) and water temperature (in the range 15–33°C); pH (5.77–7.32); and turbidity (1.4–567 NTU). The high FCC ranged from
2.0 × 101 to 1.6 × 106 MPN/100 ml and exceeded the WHO standards for drinking water and water used for fresh-produce irrigation, and correlated
positively (P < 0.05) with conductivity (in the range 68–1,029 μS/cm); TDS (10.0–70.0 mg/l); TSS (10.0–70.0 mg/l); Cl (7.5–181 mg/l); PO4−P (0.01–0.41 mg/l); NO3−N (0.6–3.8 mg/l) and BOD5 (0.1–14.9 mg/l). The main pollution sources were municipal wastewater, stormwater runoffs, the ABU sewage treatment plant,
abattoir effluents and irrigation farms treated with chemical fertilisers. We conclude that these water bodies are potentially
hazardous to public health and that proper sewage treatment and river quality monitoring are needed to warn against hazards
to public health. 相似文献
4.
Determination of landscape beauties through visual quality assessment method: a case study for Kemaliye (Erzincan/Turkey) 总被引:1,自引:0,他引:1
Kemaliye (Erzincan/Turkey) is the member of European Association of Historic Towns and Regions. The aim of this study was
to reveal the visual richness of the town; to identify the relationship between landscape spatial pattern and visual quality
of the landscape and to offer some suggestions for the future planning in regarding to these visual beauties. The visual quality
assessment method was used in this study. The results of the study revealed three landscape types that have the highest visual
quality. Among those, the highest one is urban scenery 3 (US3; VQP = 5.9400), the second is geological structure scenery 5
(GSS 5; VQP = 5.9200) and the third natural scenery 3 (NS3; VQP = 5.9133). Visual quality assessment showed that urban pattern,
geological structure and natural resources of the region also have visual value. The relationships between landscape spatial
pattern and visual quality of landscape indicated that certain characteristics of landscape affected the quality. For instance,
as the texture level decreased in natural landscapes and as the green areas increased in geological structure, visual preferences
ratio increased. Some suggestions were also made regarding the visual resources use in the region. 相似文献
5.
Bhoj Raj Pant 《Environmental monitoring and assessment》2011,178(1-4):477-485
A study was undertaken to assess the quality of groundwaters in the Kathmandu Valley, Nepal. The groundwater samples were randomly collected from shallow well, tube well, and deep-tube wells located at different places of Kathmandu, Lalitpur, and Bhaktapur districts in the Kathmandu valley. Physical, chemical, and microbiological parameters of the samples were evaluated to estimate the groundwater quality for drinking water. It was found that the groundwater in the valley is vulnerable to drink due to presence of iron and coliform bacteria. Iron was estimated to be much higher then the acceptable limit of World Health Organization (WHO) drinking-water quality guidelines (1.9 mg/L). Total coliform bacteria enumerated in groundwaters significantly exceeded the drinking-water quality standard and observed maximum coliform (267 CFU/100 mL) in shallow wells. The electrical conductivity and turbidity were found to be 875 ??S/cm and 55 NTU, respectively, which are above the WHO recommendations for drinking water guidelines. However, pH value was measured within the acceptable limit. Arsenic, chloride, fluoride, and hardness concentrations were found to be in agreement with the recommendations of WHO drinking-water quality guidelines. 相似文献
6.
This study investigated the presence of total mercury (Hg) and organic mercury levels in the muscle of 19 common fresh water
fish species captured from river Ganges, West Bengal, India. The total mercury level found in our study may not cause any
toxic effect, but the methyl mercury (MeHg) level in some freshwater fish species was surprisingly very high and toxically
unacceptable. The results of mercury analysis in various specimens indicated that some fish muscles tended to accumulate high
levels of Hg, and approximately 50–84% of Hg was organic mercury. A strong positive correlation between mercury levels in
muscle with food habit and fish length (age) was found. Wallago attu possessed the highest amount of organic mercury in their muscle tissues, and it was 0.93 ± 0.61 μg Hg/g of wet weight. Whereas
in small-sized fishes Eutropiichthys murius, Puntius sarana, Cirrhinus mrigala, Mystus vittatus or Mystus gulio, and Tilapia mossambicus, it was below the detection limit. Contamination in Catla catla (0.32 ± 0.11), Anguilla bengalensis bengalensis (0.26 ± 0.07 μg Hg/g), Chitala chitala (0.25 ± 0.18), Rita rita (0.34 ± 0.14), and Ompok pabda (0.26 ± 0.04) was also above the 0.25 μg Hg/g of wet weight, the limit set by the PFA for the maximum level for consumption
of fish exposed to MeHg. Though in Labeo rohita (0.12 ± 0.03), Mastacembelus armatus (0.17 ± 0.02), Pangasius pangasius (0.12 ± 0.16), Bagarius bagarius (0.12 ± 0.01), and Clupisoma garua (0.1 ± 0.01), concentration was below the recommended level, in Lates calcarifer (0.23 ± 0.0) and Mystus aor (0.23 ± 0.1), it was threatening. Interestingly, a low concentration of Hg was found in post-monsoon samples. 相似文献
7.
Retrieval of total suspended matter (TSM) and chlorophyll-a (Chl-a) concentration from remote-sensing data for drinking water resources 总被引:1,自引:0,他引:1
Song K Li L Wang Z Liu D Zhang B Xu J Du J Li L Li S Wang Y 《Environmental monitoring and assessment》2012,184(3):1449-1470
The concentrations of chlorophyll-a (Chl-a) and total suspended matter (TSM) are major water quality parameters that can be retrieved using remotely sensed data. Water
sampling works were conducted on 15 July 2007 and 13 September 2008 concurrent with the Indian Remote-Sensing Satellite (IRS-P6)
overpass of the Shitoukoumen Reservoir. Both empirical regression and back-propagation artificial neural network (ANN) models
were established to estimate Chl-a and TSM concentration with both in situ and satellite-received radiances signals. It was found that empirical models performed
well on the TSM concentration estimation with better accuracy (R
2 = 0.94, 0.91) than their performance on Chl-a concentration (R
2 = 0.62, 0.75) with IRS-P6 imagery data, and the models accuracy marginally improved with in situ spectra data. Our results
indicated that the ANN model performed better for both Chl-a (R
2 = 0.91, 0.82) and TSM (R
2 = 0.98, 0.94) concentration estimation through in situ collected spectra; the same trend followed for IRS-P6 imagery data
(R
2 = 0.75 and 0.90 for Chl-a; R
2 = 0.97 and 0.95 for TSM). The relative root mean square errors (RMSEs) from the empirical model for TSM (Chl-a) were less than 15% (respectively 27.2%) with both in situ and IRS-P6 imagery data, while the RMSEs were less than 7.5% (respectively
18.4%) from the ANN model. Future work still needs to be undertaken to derive the dynamic characteristic of Shitoukoumen Reservoir
water quality with remotely sensed IRS-P6 or Landsat-TM data. The algorithms developed in this study will also need to be
tested and refined with more imagery data acquisitions combined with in situ spectra data. 相似文献
8.
Bulgaroni V Rovedatti MG Sabino G Magnarelli G 《Environmental monitoring and assessment》2012,184(5):3307-3314
A pilot study was conducted to evaluate the usefulness of salivary cholinesterase and carboxylesterase as biomarkers of exposure
to environmental organophosphate pesticides. Ninety samples were obtained from women and 62 samples from their preschool-aged
children who live near an agricultural area of the Upper Valley of the Negro River (Patagonia, Argentina) where pesticides
are applied 6 months a year. Each participant donated two samples under similar conditions: one in the pre-exposure period
and another during the pulverization period. Demographic information, potential confounders, and risk behaviors were registered.
Active or passive smoking had no effect on these enzyme activities in either group. During the pulverization period, cholinesterase
activity was not detectable in 76% of the children's samples and 23% of the mothers' samples. Comparing samples collected
during the pulverization period with respect to the pre-pulverization period, the average mother and child cholinesterase
activity decreased by 65.7% (p < 0.001) and 85.8% (p < 0.001), respectively. Also, mother and child carboxylesterase activity decreased by 27.5% (p < 0.001) and 41.9% (p < 0.01), respectively. Child carboxylesterase activity in the pulverization period was associated to the habit of eating
dust outdoors (p < 0.01). The most frequent inhibition levels observed for cholinesterase and carboxylesterase activity were between 70–100%
and 0–29%, respectively, in both groups studied. This shows that at the same level of exposure, cholinesterase was more sensitive
to inhibition than carboxylesterase. Therefore, carboxylesterase might more properly reflect the degree of environmental organophosphate
exposure and may have potential as a novel tool for biomonitoring. 相似文献
9.
S. P. Pathak S. Kumar P. W. Ramteke R. C. Murthy J. W. Bhattacherjee K. Gopal 《Environmental monitoring and assessment》1994,33(2):151-160
A total of 1094 water samples from 326 springs, 207 streams, 183 dug wells, 151 piped supplies, 90 tube wells, 75 hand pumps, 60 rivers and 2 lakes were collected from eight northern and six north-eastern districts of India. Samples were analysed to assess their potability by estimating the level of heavy metals and bacterial (coliform and faecal coliform) contaminations. Iron was found in a maximum number (53%) of water samples from hand pumps, followed by lead in 43% of the tube wells, chromium in 16% of dug wells, cadmium in 13% of streams and manganese in 7% of hand pumps above their maximum admissible concentrations (MACs). Maximum metal pollution has been observed in a considerable number of water samples from Doda, followed by Almora, Mirzapur and Bankura. Hand pump water samples exhibited maximum metal pollution followed by dug well, spring, stream and river water samples. Contamination of coliform and/or faecal coliform bacteria ranged between 41% and 67% of water samples from open water sources but it was also less, i.e. 6–15% of water samples from tube wells and hand pumps. In general, 42–85% of water samples from districts surveyed, except from Jammu (18%) and Mirzapur (27%), were found to be bacteriologically unsatisfactory. Since toxic metals and pathogenic bacteria pose a risk to public health, monitoring of drinking water sources is required. 相似文献
10.
Barman SC Singh R Negi MP Bhargava SK 《Environmental monitoring and assessment》2008,137(1-3):495-504
The present study deals with the effect of fireworks on ambient air quality during Diwali Festival in Lucknow City. In this
study, PM10, SO2, NO
x
and 10 trace metals associated with PM10 were estimated at four representative locations, during day and night times for Pre Diwali (day before Diwali) and Diwali
day. On Diwali day 24 h average concentration of PM10, SO2, and NO
x
was found to be 753.3, 139.1, and 107.3 μg m−3, respectively, and these concentrations were found to be higher at 2.49 and 5.67 times for PM10, 1.95 and 6.59 times for SO2 and 1.79 and 2.69 for NO
x
, when compared with the respective concentration of Pre Diwali and normal day, respectively. On Diwali day, 24 h values for
PM10, SO2, and NO
x
were found to be higher than prescribed limit of National Ambient Air Quality Standard (NAAQS), and exceptionally high (7.53
times) for PM10. On Diwali night (12 h) mean level of PM10, SO2 and NO
x
was 1,206.2, 205.4 and 149.0 μg m−3, respectively, which was 4.02, 2.82 and 2.27 times higher than their respective daytime concentrations and showed strong
correlations (p < 0.01) with each other. The 24 h mean concentration of metals associated with PM10 was found to be in the order of Ca (3,169.44) > Fe (747.23) > Zn (542.62) > Cu (454.03), > Pb (307.54) > Mn (83.90) > Co
(78.69) > Cr (42.10) > Ni (41.47) > Cd (34.69) in ng m−3 and all these values were found to be higher than the Pre Diwali (except Fe) and normal day. The metal concentrations on
Diwali day were found to be significantly different than normal day (except Fe & Cu). The concentrations of Co, Ni, Cr and
Cd on Diwali night were found to be significantly higher than daytime concentrations for Pre Diwali (control). The inter correlation
of metals between Ca with Pb, Zn with Ni and Cr, Cu with Co, Co with Mn, Ni with Cd, Mn with Cd, Ni with Cd and Cr, and Cr
with Cd showed significant relation either at p < 0.05 or P < 0.01 levels, which indicated that their sources were the same. The metals Cu, Co, Ni, Cr and Cd showed significant (p < 0.01) association with PM10. These results indicate that fireworks during Diwali festival affected the ambient air quality adversely due to emission
and accumulation of PM10, SO2, NO
x
and trace metals.
ITRC Communication Number 2538 相似文献
11.
Statistical source identification of metals in groundwater exposed to industrial contamination 总被引:1,自引:0,他引:1
Tariq SR Shah MH Shaheen N Jaffar M Khalique A 《Environmental monitoring and assessment》2008,138(1-3):159-165
Levels of selected metals Na, Ca, Mg, K, Fe, Mn, Cr, Co, Ni, Cd, Pb and Mn were estimated by flame atomic absorption spectrophotometry
in groundwater samples from Kasur, a significant industrial city of Pakistan. Salient mean concentration levels were recorded
for: Na (211 mg/l), Ca (187 mg/l), Mg (122 mg/l), K (87.7 mg/l), Fe (2.57 mg/l) and Cr (2.12 mg/l). Overall, the decreasing
metal concentration order was: Na > Ca > Mg > K > Fe > Cr > Zn > Co > Pb > Mn > Ni > Cd. Significantly positive correlations
were found between Na–Cr (r = 0.553), Na–Mn (r = 0.543), Mg–Fe (r = 0.519), Mg–Cr (r = 0.535), Pb–K (r = 0.506) and Pb–Ni (r = 0.611). Principal Component Analysis and Cluster Analysis identified tannery effluents as the main source of metal contamination
of the groundwater. The present metal data showed that Cr, Pb and Fe levels were several times higher than those recommended
for water quality by WHO, US-EPA, EU and Japan. The elevated levels of Cr, recorded as 21–42 fold higher compared with the
recommended quality values, were believed to originate from the tanning industry of Kasur. 相似文献
12.
The chemical forms and ecological risk of As were characterized in the sediment of the Daliao River System (DRS), which has
been affected by long-term intensive industrial, urban, and agricultural activities. Twenty-seven samples of surface sediment
were collected and analyzed for total As content and that of its chemical forms. The results indicated that the average total
As content in the sediment was 9.83 mg kg − 1 but that the levels ranged from 1.57 to 83.09 mg kg − 1. At the sites near cities, mining sites, and the estuary of the DRS, it is likely that adverse effects on aquatic organisms
occur, due to As levels in the sediment that are often higher than the threshold effect level and occasionally higher than
the probable effect level. A selectively sequential extraction indicated that the majority of As in the sediment was bound
to Fe oxides (62.1%), with moderate proportions of residual As (19.8%), specifically adsorbed As (17.9%), and a low proportion
of non-specifically adsorbed As (1.1%). In addition, the content of Fe in the sediment was positively and significantly correlated
with the contents of amorphous and crystalline Fe oxide-bound As, confirming the crucial role of Fe oxides in immobilizing
high amounts of As in superficial environments. The average molar ratio of As to Fe was 1.18 × 10 − 4 in the surface sediment of the DRS, similar to that of natural Fe oxides, but much lower than that of synthesized Schwertmannite.
Therefore, the release of As under reduced and low pH conditions can cause serious problems for water resources and for living
organisms. 相似文献
13.
Nagpur City located in semiarid area of central India is a fast-growing industrial centre. In recent years, rapid development
has created an increased demand for drinking water, which is increasingly being fulfilled by groundwater abstraction. The
present study was undertaken to assess major ion chemistry of shallow groundwater to understand geochemical evolution of groundwater
and water quality for promoting sustainable development and effective management of groundwater resources. A total of 47 water
samples were collected from shallow aquifer of selected parts of the city and the water chemistry of various ions viz. Ca2 + , Mg2 + , Na + , K + , CO3 2-_{3}^{\ \, 2-}, HCO3 -_{3}^{\ \, -}, Cl − , SO4 2-_{4}^{\ \,2-} and NO3 -_{3}^{\ \,-} are carried out. The chemical relationships in Piper diagram identify Ca–HCO3–Cl and mixed Ca–Na–HCO3–Cl as most prevalent water types. Alkaline earth exceeds alkalis and weak acids exceed strong acids. Ionic ratios and Gibb’s
diagram suggest that silicate rock weathering and anthropogenic activities are the main processes that determine the ionic
composition in the study area. The nitrate appeared as a major problem of safe drinking water in this region. We recorded
highest nitrate concentration, i.e., 411 mg/l in one of the dug well. A comparison of groundwater quality in relation to drinking
water quality standards revealed that about half of the shallow aquifer samples are not suitable for drinking. 相似文献
14.
Leachate Characterization and Assessment of Groundwater Pollution Near Municipal Solid Waste Landfill Site 总被引:6,自引:0,他引:6
Leachate and groundwater samples were collected from Gazipur landfill-site and its adjacent area to study the possible impact
of leachate percolation on groundwater quality. Concentration of various physico-chemical parameters including heavy metal
(Cd, Cr, Cu, Fe, Ni, Pb and Zn) and microbiological parameters (total coliform (TC) and faecal coliform (FC)) were determined
in groundwater and leachate samples. The moderately high concentrations of Cl−, NO−
3, SO2−
4, NH+
4, Phenol, Fe, Zn and COD in groundwater, likely indicate that groundwater quality is being significantly affected by leachate
percolation. Further they proved to be as tracers for groundwater contamination. The effect of depth and distance of the well
from the pollution source was also investigated. The presence of TC and FC in groundwater warns for the groundwater quality
and thus renders the associated aquifer unreliable for domestic water supply and other uses. Although some remedial measures
are suggested to reduce further groundwater contamination via leachate percolation, the present study demand for the proper
management of waste in Delhi. 相似文献
15.
Wastewater pollution in industrial areas is one of the most important environmental problems. Heavy metal pollution, especially
chromium pollution in wastewater sources from dyeing and tannery has affected the life on earth. This pollution can affect
all ecosystems and human health directly or by food chain. Therefore, the determination of chromium in this study is of great
importance. Dil Creek is located in the eastern Marmara region and discharges into the Izmit Gulf. This water source is used
for irrigation in agriculture and as drinking water for animals. In this study, a rapid, sensitive and selective method for
the speciative direct determination of Cr (III) and Cr (VI) in dyeing waste water samples collected from the nearest station
to Izmit Gulf of Dil Creek in May 2006 by inductively coupled plasma-atomic emission spectrometry (ICP-AES) has been developed.
An analysis of a given sample is completed in about 15 min for ICP-AES the method. As the result of the chromium analysis,
the limit of quantification (LOQ) for the Cr (III), Cr (VI) and total Cr were founded as 0.0111 ± 0.0002 mg/l (RSD, 1.80%),
0.0592 ± 0.0010 mg/l (RSD, 1.70%) and 0.0703 ± 0.0020 mg/l (RSD, 2.84%) respectively. In addition, the general mathematical
formula has been developed to calculate the concentration of Cr(III), which can be applied to any other metal species. The
result of Cr (VI) analysis indicated that water quality of Creek was IV. class quality according to the inland water classification.
In order to validate the applied method, recovery studies were performed. 相似文献
16.
Fecal source tracking by antibiotic resistance analysis on a watershed exhibiting low resistance 总被引:2,自引:0,他引:2
The ongoing development of microbial source tracking has made it possible to identify contamination sources with varying accuracy,
depending on the method used. The purpose of this study was to test the efficiency of the antibiotic resistance analysis (ARA)
method under low resistance by tracking the fecal sources at Turkey Creek, Oklahoma exhibiting this condition. The resistance
patterns of 772 water-isolates, tested with nine antibiotics, were analyzed by discriminant analysis (DA) utilizing a five-source
library containing 2250 isolates. The library passed various representativeness tests; however, two of the pulled-sample tests
suggested insufficient sampling. The resubstitution test of the library individual sources showed significant isolate misclassification
with an average rate of correct classification (ARCC) of 58%. These misclassifications were explained by low antibiotic resistance
(Wilcoxon test P < 0.0001). Seasonal DA of stream E. coli isolates for the pooled sources human/livestock/deer indicated that in fall, the human source dominated (P < 0.0001) at a rate of 56%, and that human and livestock respective contributions in winter (35 and 39%), spring (43 and
40%), and summer (37 and 35%) were similar. Deer scored lower (17–28%) than human and livestock at every season. The DA was
revised using results from a misclassification analysis to provide a perspective of the effect caused by low antibiotic resistance
and a more realistic determination of the fecal source rates at Turkey Creek. The revision increased livestock rates by 13–14%
(0.04 ≤ P ≤ 0.06), and decreased human and deer by 6–7%. Negative misclassification into livestock was significant (0.04 ≤ P ≤ 0.06). Low antibiotic resistance showed the greatest effect in this category. 相似文献
17.
Woli KP Hayakawa A Kuramochi K Hatano R 《Environmental monitoring and assessment》2008,137(1-3):251-260
River water quality was evaluated with respect to eutrophication and land use during spring snowmelt and summer base flow
periods in Abashiri (mixed cropland-livestock farming) and Okoppe (grassland-based dairy cattle farming), eastern Hokkaido,
Japan. Water from rivers and tributaries was sampled during snowmelt and summer base flow periods in 2005, and river flow
was measured. Total N (TN), NO3–N, and Si concentrations were determined using standard methods. Total catchment and upland areas for each sampling site
were determined with ArcGIS hydrology modeling software and 1:25,000-scale digital topographic maps. Specific discharge was
significantly higher during snowmelt than during base flow. In both areas, TN concentrations increased, whereas Si concentrations
decreased, with increased specific discharge, and were significantly higher during snowmelt. The Si:TN mole ratio decreased
to below or close to the threshold value for eutrophication (2.7) in one-third of sites during snowmelt. River NO3–N concentrations during base flow were significantly and positively correlated with the proportion of upland fields in the
catchment in both the Abashiri (r = 0.88, P < 0.001) and Okoppe (r = 0.43, P < 0.01) areas. However, the regression slope, defined as the impact factor (IF) of water quality, was much higher in Abashiri
(0.025) than in Okoppe (0.0094). The correlations were also significantly positive during snowmelt in both areas, but IF was
four to eight times higher during snowmelt than during base flow. Higher discharge of N from upland fields and grasslands
during snowmelt and the resulting eutrophication in estuaries suggest that nutrient discharge during snowmelt should be taken
into account when assessing and monitoring the annual loss of nutrients from agricultural fields. 相似文献
18.
Bushra Ahmed Al-Hammad Magda Magdy Abd El-Salam Sahar Yassin Ibrahim 《Environmental monitoring and assessment》2014,186(11):7709-7718
This study is planned to perform a sanitary survey of the largest sewage treatment plant in Riyadh, KSA, fortnightly for 6 months to examine its effluent quality as an example for the growing dependence on reuse of treated municipal wastewater in agricultural irrigation purposes to cope with increasing water shortage. The biological and physico-chemical parameters of 12 wastewater samples from the plant were examined using standard methods. The physico-chemical analysis indicated that the surveyed municipal wastewater treatment plant contained some of the studied parameters, such as turbidity, total suspended solids, biochemical oxygen demand, chemical oxygen demand and residual chlorine above the maximum permissible wastewater limits set by the Saudi Standards. However, heavy metal concentrations in all samples were lower than the recommended standards. Total and faecal coliform counts were above the permissible limits indicating poor sanitation level. Fifty percent of all wastewater samples were contaminated with faecal coliforms but, surprisingly, Escherichia coli were only detected in 8.3 % of the samples. Regular monitoring and enhancement of microbial and physico-chemical parameters of the wastewater quality served by different wastewater treatment plants for reuse in agricultural irrigation is recommended to preserve the environment and public health. 相似文献
19.
Different multivariate statistical analysis such as, cluster analysis, principal component analysis, and multidimensional
scale plot were employed to evaluate the trophic status of water quality for four monitoring stations. The present study was
carried out to determine the physicochemical parameters of water and sediment characteristics of Pondicherry mangroves—southeast
coast of India, during September 2008–December 2010. Seasonal variations of different parameters investigated were as follows:
salinity (10.26–35.20 psu), dissolved oxygen (3.71–5.33 mg/L), pH (7.05–8.36), electrical conductivity (26.41–41.33 ms−1), sulfide (1.98–40.43 mg/L), sediment texture sand (39.54–87.31%), silt (9.89–32.97%), clay (3.06–31.20%), and organic matter
(0.94–4.64%). pH, temperature, salinity, sand, silt, clay, and organic matter indicated a correlation at P < 0.01. CA grouped the four seasons in to four groups (pre-monsoon, monsoon, post-monsoon, summer) and the sampling sites
in to three groups. PCA identified the spatial and temporal characteristics of trophic stations and showed that the water
quality was worse in stations 3 and 4 in the Pondicherry mangroves. 相似文献
20.
Anthropogenic activities associated with industrialization, agriculture and urbanization have led to the deterioration in
water quality due to various contaminants. To assess the status of urban drinking water quality, samples were collected from
the piped supplies as well as groundwater sources from different localities of residential, commercial and industrial areas
of Lucknow City in a tropical zone of India during pre-monsoon for estimation of coliform and faecal coliform bacteria, organochlorine
pesticides (OCPs) and heavy metals. Bacterial contamination was found to be more in the samples from commercial areas than
residential and industrial areas. OCPs like α,γ-hexachlorocyclohexane and 1,1 p,p-DDE {dichloro-2, 2-bis(p-chlorophenyl) ethene)}
were found to be present in most of the samples from study area. The total organochlorine pesticide levels were found to be
within the European Union limit (0.5 μg/L) in most of the samples. Most of the heavy metals estimated in the samples were
also found to be within the permissible limits as prescribed by World Health Organization for drinking water. Thus, these
observations show that contamination of drinking water in urban areas may be mainly due to municipal, industrial and agricultural
activities along with improper disposal of solid waste. This is an alarm to safety of public health and aquatic environment
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