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171.
于2020—2021年对某市20个监测井80份地下水样本进行了调查。采用因子分析和聚类分析法以地下水中阳离子浓度为研究对象进行溯源分析。结果表明,地下水中阳离子浓度会受到不同程度、不同类别的人类活动影响,其阳离子的来源呈现多样化的特点,其中铅、铜、铝、锰为农业面源来源,铵、钠、总硬度是工业来源,另外,砷、铁及锌等为自然来源,而在自然来源中出现的砷、铁阳离子的富集现象,很明显是受到了城镇化及工业化的影响。锌与氢离子可能是地下水中pH值受到人类活动的影响,或者是地表水的侧向补给带来的影响。 相似文献
172.
采用C18固相膜萃取对地下水中15种多环芳烃进行富集净化,以二氯甲烷作洗脱溶剂,高效液相色谱法,荧光检测器测定。对萃取、浓缩和色谱条件进行优化,在1.ooixg/L~40.0μg/L范围内测定标准系列溶液并绘制标准曲线,相关系数R2〉0.999;15种多环芳烃的仪器检出限为0.4ng/L~3.0ng/L;对地下水样品加标,平均回收率在75.7%~96.7%之间;标准溶液平行测定7次的RSD为3.1%~11.9%。 相似文献
173.
为了解华东某市老城区潜层地下水硝酸盐分布特征,对老城区地下水现场采样,运用统计学软件spss中的Pearson相关系数和sufer软件Kriging插值方法分析数据,研究了无机氮与地球化学因素间的相关性,同时绘制了p H值、总硬度、硝酸盐、亚硝酸盐的空间分布图。结果表明,硝酸盐是该地区地下水中无机氮的主要存在形态,其所占总氮含量为45.5%~74.8%,封口井的硝酸盐的含量明显低于敞口井的含量,其硝酸盐所占比例最低达到2.2%,且敞口井均受到污染;从相关性的角度来看,氮的转化受到Fe影响较弱。同时氮的形态与p H值、矿化度(TDS)、电导率(EC)等地球化学因素相关水平显著;从分布特征来看,地下水环境中硝酸盐和亚硝酸盐含量东北部高于西南部;不同形态氮的相互转化影响地下水p H值和总硬度,致使p H值的高值区为西南部,而总硬度高值区为东北部。 相似文献
174.
Geochemical study of groundwater from a structurally deformed granitic terrain near Hyderabad (India) was carried out to understand
and evaluate the hydrogeochemical processes and quality of groundwater. Several trace elements (Fe, Mn, Be, Al, V, Cr, Co,
Ni, Cu, Zn, As, Sr, Mo, Cd, Sb, Ba, Pb, U) along with major ions and minor elements were precisely estimated in shallow and
drilled wells to know the suitability of water for drinking and irrigation purposes. Analytical data shows that pH and major
ion chemistry in dug wells and bore wells do not vary significantly, while some trace elements (Fe, Mn, Al, Be, Co, Pb, U
and Zn) vary in dug wells and bore wells, which can be attributed to differential mineral weathering and dissolution/precipitation
reactions along fractures/joints. Although the water is not potable, it was found to be suitable for irrigation with little
danger in the development of harmful level of exchangeable sodium. It is inferred that the chemical composition of the groundwater
in this region is likely to have its origin from silicate weathering reactions and dissolution/precipitation processes supported
by rainfall and groundwater flow. 相似文献
175.
The Natural Vegetation Responses to the Groundwater Change Resulting from Ecological Water Conveyances to the Lower Tarim River 总被引:4,自引:0,他引:4
This paper takes the ecological water conveyance project (EWCP) that transfers water from the Bosten Lake, to Daxihaizi Reservoir, and finally to the Taitema Lake as a case study to analyze
the dynamic change of the groundwater depth, the vegetation responses to the elevation of the groundwater depth as well as
the relationship between the groundwater depth and the natural vegetation. The results from many years’ monitoring in field
indicate: (1) the groundwater depth has been elevating gradually with the increase in the times of watering and the elevation
range has been expanding continuously in the lower reaches of Tarim River. Correspondingly, the natural vegetation has a favorable
response to the elevation of the groundwater depth. The change of the natural vegetation has accordance with that of the groundwater
depth. Such facts not only show that groundwater is a key factor to the growth of the native vegetation but also prove it
is feasible that the degraded ecosystem can be restored and protected by the EWCP; (2) the results of analysis of the spatial-temporal response of the natural vegetation to watering reveals that the beneficial
influence of the EWCP on the ecosystem in the lower Tarim River is a long-term process; (3) in terms of the function and structure of ecosystem
after watering in the lower reaches of Tarim River, the EWCP does not still reach the goal of ecological restoration at a large spatial scale at present. Based on such monitoring results,
some countermeasures and suggestions for the future restoration strategy are proposed so as to provide a theoretical basis
for restoring and protecting the ecosystem in Tarim River, and meanwhile it can also provide some scientific references for
implementing the similar ecological projects in other areas. 相似文献
176.
Analysis and evaluation of nitrate levels in groundwater at Al-Hashimiya area, Jordan 总被引:3,自引:0,他引:3
Obeidat MM Massadeh AM Al-Ajlouni AM Athamneh FS 《Environmental monitoring and assessment》2007,135(1-3):475-486
Water with high nitrate concentration (NO3
−) is unfit for human consumption, especially when its concentration exceeded the threshold limit (50 mg/l) recommended by
the health authorities such as the World Health Organization (WHO). In Jordan, there is a great concern for determination
and monitoring organic and inorganic pollutants that may reach groundwater. Nitrate is highly mobile and present in domestic,
agricultural and industrial waste in Jordan, and thus this study focused initially on nitrate as both a contaminant of concern
and as an indicator of potential groundwater contamination. The present study determined the extent of nitrate contamination
in groundwater in the study area and examined the likely sources of NO3
−. A total of 248 groundwater samples were collected from 16 wells in different sites of Al-Hashimiya area, Zerqa Governorate,
Jordan, and investigated for NO3
− concentrations. Moreover, measurements of temperature, electrical conductivity and pH were carried out in the field. Analysis
was carried out according to the methods described by the American Public Health Association (APHA). Results showed that there
was a dramatic increasing in NO3
− concentrations from the year 2001 to 2006 for some selected wells in the present study. NO3
− concentration in 2006 was ranged from 10 to 330 mg/l with an average of 77 mg/l. Overall, groundwater had elevated nitrate
concentration with 92% of the samples containing more than 20 mg/l NO3
−, indicating the influence of human activities. This study has shown that there is a strong correlation between the nitrate
concentration and the wastewater effluents as a source of pollution. 相似文献
177.
Environmental exposure to arsenic (As) in the Kutahya region of the western Anatolia, Turkey has been reported to cause various
types of arsenic-associated skin disorders (Dogan, Dogan, Celebi, & Baris, 2005). A geological and mineralogical study was conducted to find the sources and distribution of the As. Geogenic (background)
levels were measured in samples collected from various sources in the Gediz, Simav, Tavsanli, Emet, Yoncali, Yenicekoy, and
Muratdagi areas of the Kutahya region. Based on this analysis, we determined that natural sources are a domineering factor
affecting the distribution of As, which was found: (1) mainly in evaporitic minerals, including colemanite (269–3900 ppm)
and gypsum (11–99,999 ppm), but also in alunite (7–10 ppm) and chert (54–219 ppm); (2) in secondary epithermal gypsum, which
has a high concentration of As in the form of realgar and orpiment along fracture zones of Mesozoic and Cenozoic carbonate
aquifers; (3) in rocks, including limestone/dolomite (3–699 ppm) and travertine (5–4736 ppm), which are relatively more enriched
in As than volcanics (2–14 ppm), probably because of secondary enrichment through hydrological systems; (4) in coal (1.9–46.5 ppm)
in the sedimentary successions of the Tertiary basins; (5) in thermal waters, where As is unevenly distributed at concentrations
varying from 0.0–0.9 mg/l. The highest As concentrations in thermal water (Gediz and Simav) correlate to the higher pH (7–9.3)
and T (60–83°C) conditions and to the type of water (Na–HCO3–SO4 with high concentration of Ca, Mg, K, SiO2, and Cl in the water). Changes in pH can be related to some redox reactions, such as the cation exchange reactions driving
the dissolution of carbonates and silicates. Fe-oxidation, high pH values (7–9.3), presence of other trace metals (Ni, Co,
Pb, Zn, Al), increased salinity (Na, Cl), high B, Li, F, and SiO, high Fe, SO4 (magnetite, specularite-hematite, gypsum), and graphite, and the presence of U, Fe, Cu, Pb, Zn, and B, especially in the
Emet, Gediz, and Simav areas, are the typical indicators for the geothermally affected water with high As content. A sixth
source of As in this region is the ground (0.0–10.7 mg/l) and the surface waters (0.0022–0.01 mg/l), which are controlled
by water–rock interaction, fracture system, and mixing/dilution of thermal waters. The high As concentration in groundwater
corresponds to the areas where pathological changes are greatest in the habitants. Arsenic in ground water also effects ecology.
For example, only Juriperus oxycedrus and J. varioxycedrus types of vegetation are observed in locations with the highest concentration of As in the region. Branches and roots of these
plants are enriched in As. 相似文献
178.
Factor analysis and linear regression model (LRM) of metal speciation and physico-chemical characters of groundwater samples 总被引:2,自引:0,他引:2
An approach is described for viewing the interrelationship between different variables and also tracing the sources of pollution
of groundwater of north Chennai (India). The data set of 43 variables which include major ions, minor ions and trace metal
speciation (Cu, Pb, Cd and Zn) collected during the pre-monsoon and post-monsoon seasons of the year 2000–2001, was subjected
to R-mode factor analysis to comprehend the distribution pattern of the said variables. It was found that first factor measures
salinity and hardness which explained 19.12% of the total variance (comprised of variables EC, TDS, Na+, K+, Ca2+, Mg2+, total hardness, Cl− and SO4
2−) during pre-monsoon, while it was 25.08% during post-monsoon. The second and third factors were attributed to speciation
of zinc and copper ions during both pre-monsoon and post-monsoon. Although there were two more factors, loaded with speciation
parameters of lead and cadmium, the variance of them were less than 10%. From this study it is seen that sea water intrusion,
municipal solid waste disposal are the identified sources of component of pollution. The importance of metal ions is taking
a secondary role and the anthropogenic origin-industrial activity, is the reason in the evaluation of pollution status as
they come in the second, third, fourth and fifth factors. As the trace metal speciation was grouped in separate factors, linear
regression model (LRM) with correlation analysis was applied to check its validity for prediction of speciation and to apply
LRM for rapid monitoring of water pollution. 相似文献
179.
Groundwater and water resources management play a key role in conserving the sustainable conditions in arid and semi-arid
regions. Applying some techniques that can reveal the critical and hot conditions of water resources seem necessary. In this
study, kriging and cokriging methods were evaluated for mapping the groundwater depth across a plain in which has experienced
different climatic conditions (dry, wet, and normal) and consequently high variations in groundwater depth in a 12 year led
in maximum, minimum, and mean depths. During this period groundwater depth has considerable fluctuations. Results obtained
from geostatistical analysis showed that groundwater depth varies spatially in different climatic conditions. Furthermore,
the calculated RMSE showed that cokriging approach was more accurate than kriging in mapping the groundwater depth though there was not a distinct
difference. As a whole, kriging underestimated the real groundwater depth for dry, wet, and normal conditions by 5.5, 2.2,
and 5.3%, while cokriging underestimations were 3.3, 2, and 2.2%, respectively; which showed the unbiasedness in estimations.
Results implied that in the study area farming and cultivation in dry conditions needs more attention due to higher variability
in groundwater depth in short distances compared to the other climate conditions. It is believed that geostatistical approaches
are reliable tools for water resources managers and water authorities to allocate groundwater resources in different environmental
conditions. 相似文献
180.
Löfgren S Aastrup M Bringmark L Hultberg H Lewin-Pihlblad L Lundin L Karlsson GP Thunholm B 《Ambio》2011,40(8):836-856
Recovery from anthropogenic acidification in streams and lakes is well documented across the northern hemisphere. In this
study, we use 1996–2009 data from the four Swedish Integrated Monitoring catchments to evaluate how the declining sulfur deposition
has affected sulfate, pH, acid neutralizing capacity, ionic strength, aluminum, and dissolved organic carbon in soil water,
groundwater and runoff. Differences in recovery rates between catchments, between recharge and discharge areas and between
soil water and groundwater are assessed. At the IM sites, atmospheric deposition is the main human impact. The chemical trends
were weakly correlated to the sulfur deposition decline. Other factors, such as marine influence and catchment features, seem
to be as important. Except for pH and DOC, soil water and groundwater showed similar trends. Discharge areas acted as buffers,
dampening the trends in streamwater. Further monitoring and modeling of these hydraulically active sites should be encouraged. 相似文献