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人工回灌条件下多组分溶质的反应迁移模拟 总被引：1，自引：0，他引：1
人工回灌技术在我国水资源管理中占据重要地位,但是其实施对地下水环境质量也造成了较大的影响。如何保障人工回灌条件下地下水环境质量的安全稳定性,已成为人工回灌技术发展的瓶颈。以上海市某人工回灌试验场为例,结合试验场的地质、水文地质勘探结果,以TOUGHREACT为数值模拟平台,模拟预测人工回灌条件下地下水中多组分溶质的迁移转化过程。模拟结果表明：地下水化学成分主要受混合作用、阳离子交换吸附作用及含水层矿物相溶解-沉淀作用等影响;含水介质中石英、白云石、钾长石、钠长石及蒙脱石发生溶解,方解石发生沉淀,伊利石与高岭石则先溶解后沉淀,但各矿物相反应量极其微弱;按不同压力方案回灌,水位恢复速率随压力增大而加快,但地下水中化学成分变化趋势几乎不受压力影响。 相似文献
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人工回灌过程中所发生的水-岩相互作用是影响回灌层位地下水环境质量的重要因素。采用室内实验和水文地球化学模拟等技术对人工回灌过程中的水-岩相互作用机理进行了分析。研究结果表明：受混合作用影响,随着回灌水比例的增加,混合水中TDS质量浓度降低,水化学类型由Cl·HCO3-Na型水逐渐转变为HCO3·Cl-Na·Ca型水;受水-岩作用影响,在同一混合比例条件下,随着水-岩作用的进行,混合水中TDS质量浓度升高,各主要离子质量浓度呈现升高的趋势,但只有回灌水比例占10%时,混合水TDS质量浓度才大于原始地下水（涨幅约5%）。实验介质溶解于水的离子中,Ca2+、Mg2+和HCO-3主要来源于碳酸盐矿物的溶解, Na+主要来自岩盐的溶解。在人工回灌过程中,发生的水-岩相互作用主要包括方解石、白云石、钾长石、岩盐、CO2的溶解和伊利石的沉淀。其中:钾长石溶解量与伊利石沉淀量、碳酸盐矿物溶解量与CO2溶解量的相关性较强,其相关系数分别为1.00和0.78（显著性水平为0.05）;硅酸盐矿物反应量和回灌水比例之间的相关系数为0.97（显著性水平为0.01）,相关性极强;而碳酸盐矿物反应量和回灌水比例之间的相关系数为0.52（显著性水平为0.01）,相关性较弱。上述相关性分析为确定人工回灌过程中的水-岩相互作用机理、地下水中主要离子组分的来源途径以及定量分析人工回灌对含水层介质的影响提供了依据。 相似文献
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南水北调水源进京后既要与地下水混合供水,又要将余裕水回灌地下保存,两地水源混合后的水质变化是人们关注的重要课题。本次研究中采集了丹江口地表水和北京调蓄池附近地下水,并开展了不同比例的混合试验。研究表明:丹江口水库水质优良;两地原水混合后,Na+、Mg2+、Cl-、SO2-4等组分表现为物理混合; Ca2+、HCO-3、pH值则受到碳酸平衡的强烈影响,当丹江口地表水占比较大时,混合溶液中硝化作用主导碳酸平衡,当地表水占比较小时,溶液中二氧化碳分压变化主导碳酸平衡。研究结果对南水北调进京后的供水具有重要意义。 相似文献
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《地下水》2017,(5)
再生水地下回灌过程中,研究了前处理和含水层中氮污染物在干湿交替回灌过程中的变化特征。结果表明:回灌期间,在臭氧氧化作用下会发生硝化反应,使NH4-N平均浓度降低0.196 mg/L,NO_3-N平均浓度上升为2.26 mg/L。再生水进入含水层后,水中游离氧仍然较高(6.89 mg/L),注入井附近会继续发生硝化反应,使5#井中NH4-N下降至0.07 mg/L;NO_3-N浓度在3#井到5#井之间符合线性方程y=-0.172 8 x+31.245;NO_2-N在3#井、4#井和5#井中平均浓度分别为2.02 mg/L、2.023 mg/L和2.427 mg/L。非回灌期地下水中反硝化反应使NO_3-N降低了12.241 mg/L,NO_2-N均上升了0.918 mg/L。另外,TN的变化规律与NO_3-N类似,非回灌期5#井中TN的去除率达56.6%。 相似文献
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为研究南水北调水回灌对地下水环境的影响,探讨区域地下水污染修复技术,建立区域尺度的地下水溶质运移模型,运用地下水数值模拟模型,预测和分析了在永定河河道仅使用南水北调水和南水北调水与本地水混合补给地下水两种模式下,研究区内地下水中硝酸盐氮20年内的变化趋势。结果显示,通过永定河河道回补地下水对研究区地下水起到极大的改善作用,其中部分地区硝酸盐氮浓度降低71.2%;使用南水北调水回补20年后,研究区北部的改善效果是南部的12.3~14.2倍,表明水文地质条件是区域性地下水污染修复的关键因素之一。 相似文献
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人工回灌过程中,回灌水的注入使目的含水层地下水环境发生变化,微生物条件也会随之改变,从而影响地下水环境质量及水文地球化学作用。以上海市某人工回灌试验场为例,在分析人工回灌过程中水化学演化特点的基础上,应用DGGE技术对场地回灌过程中地下水中的微生物群落结构变化进行研究,为评价人工回灌对地下水水质安全的影响提供科学的理论依据。结果表明:人工回灌作用使目的含水层地下水中的Eh值及DO质量浓度升高,分别由64.0 mV、1.12 mg/L升至534.4 mV、1.44 mg/L;同一位置处微生物群落结构与原始地下水状态的相似性随时间降低;同一时刻距离回灌井越远的监测井的微生物群落结构越接近于原始地下水状态。随着回灌的进行,目的含水层地下水中优势菌属(种)共有7种,其中Rubrivivax gelatinosus和Candidatus Accumulibacter phosphatis clade IIA str.的反硝化能力以及Rhodoferax ferrireducens对Fe3+的还原能力,对地下水水化学组分产生影响。 相似文献
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南水北调水源进京后,部分水源计划将进入密怀顺水源地回补严重亏损的地下水。水源地地下水水质的未来变化引起了人们的关注。本次研究通过开展动态含水层模拟试验,分析了南水北调水源进入含水层过程中地下水水质变化,并利用溶质运移模型,在不考虑吸附、降解等水岩相互作用等条件下,模拟了试验土柱中各常规组分的水质变化。研究表明:南水北调水源进入含水层过程中,对地下水水质的稀释作用占主导地位,其它水岩相互作用对地下水水质的影响程度较小,南水北调水源在密怀顺水源地回补地下水是可行的。为此,南水北调水源回补地下水后,不仅能够涵养并增加水源地的地下水资源,而且能够改善地下水水质,保证水源地的供水安全。 相似文献
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屋顶雨水回灌裂隙岩溶含水层连通示踪试验 总被引：1，自引：0，他引：1
雨水回灌后对岩溶水的影响分析和效果需要对回灌井和下游的观测井监测数据说明。由于岩溶含水层中岩溶发育极不均匀,在测定地下水位并判定出地下水流向的基础上,连通示踪试验是选择与回灌井相对应的观测井的有效办法。用氯化钠作为示踪剂,监测不同测井不同埋深地下水电导率随时间变化的方法确定了岩溶水观测井选址、岩溶含水层的结构及水文地质条件。示踪试验结果表明,3#观测井(西院井)可用来监测雨水回灌效果,并计算出该地区的地下水势流速在9 m/h～20 m/h之间。该成果对北方地区岩溶含水层回灌和环境评价具有重要的参考价值。 相似文献
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Bayan Muhie Hussien 《Environmental Earth Sciences》2013,70(1):453-470
The study of groundwater impact on the hydrochemical characteristic of groundwater within Mullusi aquifer, west Iraq was conducted using the chemical analysis results in 14 production wells and groundwater levels observation in 17 water wells. The interpretation of hydrochemical phenomena related to ions sources was determined based on spatial analysis maps of various hydrochemical ratios using ArcGis software. The study also determined the relation of groundwater velocity and static water levels with the hydrochemical ratios using statistical application of Curve expert v1.3 program. The variations of ion concentration were examined using the statistical significant differences for chemical constituents of water within Mullusi aquifer. The impact of dewatering due to high exploitation was explained by increasing the magnesium and chloride concentrations and lowering static water levels. Magnesium and chloride concentration may reach their maximum limits for drinking at a groundwater level of 485 m asl. Accordingly, any decline in the water level of Mullusi aquifer that occurs from 4.5 to 30.5 m may cause deterioration in groundwater quality. This study modeled the effect of groundwater depletion on the groundwater quality in a theoretical equations approach. 相似文献
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云应盆地东北部属鄂北贫水地区,赋存于古近系—第四系含水层中的地下水是当地生产、生活用水的主要来源,亟需查明含水层的结构、含水层间地下水的转化关系等基本条件,为研究区内合理开发利用地下水提供依据。本研究通过野外水文地质调查、水文地质钻探工作,将研究区划分为单层含水层与双层含水层结构两个亚区（6个小区）。并通过地下水水位动态长期监测,获取了区内不同含水层的水位动态变化特征,分析各含水层之间的水力联系,建立了区域地下水转化的概念模式,即:研究区地下水以接受山前降雨入渗及风化裂隙水侧向径流补给为主,主要以水平径流的形式经古近系孔隙-裂隙含水层及第四系孔隙承压含水层往澴水方向运移,而后进入第四系孔隙潜水含水层。地下水和地表水在不同季节补排模式不同,雨季地表水（澴水）补给地下水,旱季地下水向地表水（澴水）排泄。古近系孔隙-裂隙水与上覆第四系孔隙水联系密切互为补给,共同构成具有统一水力联系的垂向多层结构的含水系统。独特的含水层结构决定了区内地下水接受降水补给的条件较差,地下水可开采资源量总体较贫乏,建议重点利用区域地表水资源,适度开发地下水资源,推进农业节水灌溉工程,实现水资源可持续利用。 相似文献
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Saad Younes Ghoubachi 《Arabian Journal of Geosciences》2011,5(5):1103-1115
The present work deals with the groundwater aquifer of the Lower Cretaceous sandstone and its sustainable development in Sinai. The studied aquifer system is the most promising groundwater system in Sinai due to its wide extension, hug storage, and good quality. The objective of this paper aims to elucidate the hydrogeological characteristics of the Lower Cretaceous aquifer. The aquifer system occurs under confined conditions. The top surface of the Lower Cretaceous dips steeply towards the southwest direction with step faults. The average sand percent of the penetrated aquifer attains 54%. The main direction of groundwater flow is generally from southwest and locally is concentric to the center of study area related to the influence of the graben block. The aquifer has a hydraulic gradient generally reaches 0.0011 m/m and attains 0.0028 in central portion of study area. The aquifer parameters (effective porosity, transmissivity, and hydraulic conductivity) increase towards the northeast direction with increasing of the sand percentage. Durov diagram plot revealed that the groundwater has been a final stage evolution represented by a NaCl water type. The groundwater salinity increases towards the central of study area coinciding with groundwater flow. The groundwater salinity of the Lower Cretaceous aquifer is brackish water and varies from 2,510 to 5,256 ppm and unsuitable for drinking and domestic purposes. 相似文献
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作为南水北调中线工程的水源地,丹江口水库地下水的水质是影响南水北调工程建设的重要因素。为了确保丹江口水库一库清水送北京,对水库老灌河流域进行地下水采样、统计和分析,研究地下水的水化学特征,结果表明: 丹江口老灌河流域地下水偏弱碱性,属于低矿化水,Ca2+为优势阳离子,$HCO_3^-$为优势阴离子; 除$NO_3^-$外,该区主要离子浓度均符合我国及世界卫生组织推荐的饮用水标准; 丰水期和枯水期地下水的水化学类型均为Ca-Mg-HCO3型和Ca-HCO3型,水化学过程以风化-溶滤作用为主; 地下水$NO_3^-$超标13%~17%,丰水期部分区域出现Cl-型水化学类型。季节变化对老灌河流域地下水的水化学类型空间分布影响较小,地下水水质受农业、养殖业、工业遗留废渣及生活污水等影响。 相似文献
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作为南水北调中线工程的水源地,丹江口水库地下水的水质是影响南水北调工程建设的重要因素。为了确保丹江口水库一库清水送北京,对水库老灌河流域进行地下水采样、统计和分析,研究地下水的水化学特征,结果表明: 丹江口老灌河流域地下水偏弱碱性,属于低矿化水,Ca2+为优势阳离子,$HCO_3^-$为优势阴离子; 除$NO_3^-$外,该区主要离子浓度均符合我国及世界卫生组织推荐的饮用水标准; 丰水期和枯水期地下水的水化学类型均为Ca-Mg-HCO3型和Ca-HCO3型,水化学过程以风化-溶滤作用为主; 地下水$NO_3^-$超标13%~17%,丰水期部分区域出现Cl-型水化学类型。季节变化对老灌河流域地下水的水化学类型空间分布影响较小,地下水水质受农业、养殖业、工业遗留废渣及生活污水等影响。 相似文献
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Groundwater vulnerability assessment in shallow aquifer of Kathmandu Valley using GIS-based DRASTIC model 总被引：1，自引：0，他引：1
Dhundi Raj Pathak Akira Hiratsuka Isao Awata Luonan Chen 《Environmental Geology》2009,57(7):1569-1578
In this paper, groundwater aquifer vulnerability map has been developed by incorporating the major geological and hydro-geological
factors that affect and control the groundwater contamination using GIS based DRASTIC model. This work demonstrates the potential
of GIS to derive a map by overlying various spatially referenced digital data layers that portrays cumulative aquifer sensitivity
ratings across the Kathmandu Valley, Nepal, providing a relative indication of groundwater vulnerability to contamination.
In fact, the groundwater is the major natural resources in Kathmandu for drinking purpose. The decline in groundwater levels
due to the over exploitation and thus extracted water from shallow aquifer has been contaminated by the infiltration of pollutants
from polluted river and land surface is continuous and serious. As the demand for water for human and industrial use has escalated
and at the same time, the engineering and environmental costs are much higher for new water supplies than maintaining the
existing sources already in use. Management of groundwater source and protecting its quality is therefore essential to increase
efficient use of existing water supplies. Aquifer vulnerability maps developed in this study are valuable tools for environmental
planning and predictive groundwater management. Further, a sensitivity analysis has been performed to evaluate the influence
of single parameters on aquifer vulnerability assessment such that some subjectivity can be reduced to some extent and then
new weights have been computed for each DRASTIC parameters. 相似文献
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The study was carried out in order to investigate existing hydrogeochemical relationships between groundwater environment
and geological units in the Kazan trona deposit area, Ankara, Turkey. Evaluations indicate that concentrations of alkalinity,
boron, chloride and sodium in the upgradient groundwater of the Eocene sedimentary units gradually increase toward downgradient
by the interactions of saline minerals (searlesite, shortite, northupite and pyrite) present in the secondary structures (microfractures
and irregular voids) at various levels. Inverse modeling calculations suggest that the range of dissolved mass amounts in
millimoles per kilogram of water for searlesite, shortite and northupite minerals are 0.05–28.67, 2.62–24.39 and 0.01–24.19,
respectively, in the aquifer between the upgradient and downgradient locations. The ranges of accompanying calcite and dolomite
precipitations are 4.54–48.71 and 2.16–24.08 mmol per kg of water, respectively. Chemical composition of the groundwater in
the overlying Neogene sedimentary unit includes also higher concentrations of the major ions as measured in groundwater of
the underlying units. However the lack of saline mineral zones in the Neogene unit indicates that upward groundwater mixing
takes place from the underlying aquifer as also suggested by the measured upward gradient. The mixing percentage of the underlying
groundwater as determined from the nested wells ranges from 2.7 to 48.3%, from upgradient to downgradient, respectively. The
unconfined alluvium aquifer overlying the Neogene unit includes relatively dilute groundwater except in two locations, where
high-ion concentrations detected in groundwater of the underlying units are also high in these locations, suggesting upward
groundwater mixing from the underlying aquifer due to upward gradient. However, groundwater input investigations from the
alluvium aquifer to the nearby Ova stream indicate that the detected high concentrations in these locations are diluted or
sorbed by the aquifer material toward downgradient (Ova Stream). 相似文献
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拒马源泉群作为拒马河的源头,受到了较多专家和学者的关注。但这些研究多集中在地下水的水化学、水位动态、泉流量等特征上,对地下水氢氧同位素特征的分析几乎没有,且对北海泉的成因解释多为粗略的定性概述。为了说明涞源北盆地地下水的氢氧同位素特征,详细揭示北海泉的形成模式,首次系统地采集了不同含水岩组的地下水样品,测定了水样的氢氧同位素组分。结果表明:样品点δD和δ18O值均落在区域大气降水线上或附近,大气降水是研究区地下水的主要补给来源;白云岩、灰岩含水岩组高程效应较明显,径流途径长,松散含水层径流途径短,受蒸发作用较强;白云岩、灰岩含水岩组和松散含水层氘盈余d值分别为6.0‰～11.6‰、4.2‰～11.2‰、3.8‰～8.0‰,较大气降水大部分偏小,表明岩溶水和松散孔隙水经历了不同的流动过程;白云岩、灰岩含水岩组从补给区向排泄区各自流动过程中,在小西庄、香炉屯村附近断裂带发生沟通混合,然后在向盆地中心径流过程中受断层阻水上升,上升过程中又接受了松散孔隙水的补给,最后在松散岩层中出露成泉,形成北海泉。在孔隙水混入前,两者的平均补给比例大约为48.4%～57.6%和42.4%～51.6%。 相似文献
19.
Groundwater accounts for about half of the water use for irrigation in India.The fluctuation pattern of the groundwater level is examined by observing rainfall replenishment and monitoring wells.The southern part of Rajasthan has experienced abrupt changes in rainfall and has been highly dependent on groundwater over decades.This study presents the impact of over-dependence on groundwater usage for irrigation and other purposes,spatially and temporally.Hence,the objective of this study is to examine the groundwater level trend by using statistical analysis and geospatial technique.Rainfall factor was also studied in groundwater level fluctuation during 2009-2019.To analyze the influence of each well during recharge or withdrawal of groundwater,thiessien polygonswere generated from them.In the Jakham River basin,75 wells have been identified for water level trend study using the Mann-Kendall statistical test.The statistics of trend analysis show that 15%wells are experiencing water level decline in pre-monsoon,while very low percentage of wells have such trend during post-monsoon season.The average rate of water level decline is 0.245 m/a in pre-monsoon and 0.05 m/a in post-monsoon.The aquifer recharge potential is also decreasing by year.it is expected that such type of studies will help the policy makers to adopt advanced management practices to ensure sustainable groundwater resource management. 相似文献