Deuterium,Oxygen-18 and Salt Content of Drinking Water Sources in Cairo

The contineous increase of population in Cairo exceeding 10 millions inhabitants lead to the search for supplementary potable water resources in addition to the Nile River which is the principle drinking water source. Groundwater represents the main supplementary source. Evaluation of the groundwater feeding the so-called El-America Water Treatment Station which is one of the biggest potable water supplies at the northern of Cairo was carried out. Chemical and isotopic techniques were applied to estimate the suitability of this groundwater for drinking purposes. The chemical analysis includes the determination of sodium, potasium, calcium and magnesium concentrations in addition to those of chlorides, sulphates, bicarbonates and silicates, while the isotopic analysis includes oxygen-18 and deuterium. The overall chemical- and isotopic investigations determined the conditions at which the examined groundwater is suitable for drinking purposes.     

Isotope and Trace Gas Analyses as Tools to Assess Water Protection Zones in a Rural Area

Abstract

An example is presented for the application of groundwater age dating by tritium and chlorofluorocarbon (CFC) measurements to assess water protection zones. The investigation area is located in a rural area close to Osnabrück (Lower Saxony, Germany). Samples from 13 drinking water supply wells were collected in November 1995.

By using an exponential model, groundwater residence times were calculated for the wells. The tritium and CFC data showed comparable residence times with slightly higher values derived from the CFCs (especially F113). Most of the wells showed residence times around or below 10 years indicating a rather high vulnerability with respect to anthropogenic contaminations.     

A Concept and Isotope Method for Groundwater Vulnerability Assessment

Early assessment of groundwater vulnerability during groundwater exploration is an important precondition for effective protection. Any attempt to assess the “vulnerability” is confronted with the very different factors influencing this property. In this paper we present a new concept to combine different factors on an objective basis. A protection index γ is defined and it is shown that this index can be obtained by the additative combination of a self-cleaning index (γ_s), a retardation index (γ_R) and a dilution index (γ_v). For the estimation of the latter one, isotope techniques are suitable. With lumped-parameter models, easy formulae are derived for the calculation of γ_v from tritium data. The applicability of this approach was tested with data from two field studies. The results obtained show that a reasonable assessment of groundwater vulnerability can be achieved. However, a lot of problems and questions remains to be solved by further investigation.     

Seasonal and Annual Tritium Variations in Belgrade Natural Waters

Characteristics of seasonal and annual variations of tritium concentration completed with hydrological long-term data from 1976–1989 for the Belgrade alluvial aquifer are presented. The highest tritium concentration in precipitation of an average year appears at the beginning of summer with a maximum in June (9 Bq/l) when the amount of precipitation is also high (102 l/m²). The quantity of tritium precipitating in this area was also the largest in the summer, especially in June (922 Bq/M²). Similar variations of tritium concentration was found in the waters of the Danube and the Sava with maxima 11.3 Bq/l (July) and 9 Bq/l (June) respectively. Tritium concentrations orginated from snowmelt influence to the occurrence of higher values during that period which is more distinct in the Sava. The groundwaters and particularly ones in the Ranney wells follow changes of levels, temperature and tritium content in the alluvial of Sava with a time lag from a few days to a month. During the period of observation tritium content was decreasing in all studied waters. The decrease was faster in precipitation (11.2 to 3.0 Bq/l) and the Sava and Renney wells (10.6 to 3.0 Bq/l) than in the Danube (13.1 to 5.2 Bq/l).     

Use of Isotope Methods for the Development of a New Structural-Geological Model in the Finne Region

Abstract

Since the 1960s intensive isotope hydrogeological studies have been carried out in the Finne mountain range between Herrengosserstedt in Thuringia and the River Unstrut near Karsdorf in Saxony-Anhalt. The new railway line Erfurt-Leipzig/Halle, a part of the traffic projects German Union - Railway-No. 8-, will cross this area with two tunnels, each of which is 6 km long. The tunnelling of the Middle Bunter rocks on the west side involves the crossing of an area with deep wells used for drinking water supply.

To clarify the hydrodynamic situation in this area, the planning company for railway construction German Union (PB DE) contracted Trischler und Partner to carry out an extensive exploration programme. This programme included not only investigations using the isotopes ²H, ¹⁸O, ³H, ¹³C and ¹⁴C, but also single measurements of chlorofluorocarbons (CFC) and a multitude of hydrochemical analyses.

Because of stratum related ground water sampling, an aquifer related evaluation of the investigation results was possible. Based on these results a fundamentally new structural-geological model for the investigation area was developed. In addition to its great importance for the tunnel planning, with the new model it will be possible to solve urgent questions concerning the drinking water supply in this region.     

Z箍缩驱动聚变-裂变混合堆氚燃料循环系统氚盘存量与氚自持初步分析

为研究氚自持条件,建立了Z-FFR氚分析模型,基于理论方程和氚平均滞留时间方法进行计算,得到稳态运行时排灰气处理系统、氚增殖提取系统、同位素分离系统、水去氚化系统的氚质量流分别为52.30,25.40,81.30,3.60 g/day,对应的氚盘存量为52.30,25.40,8.13,1.80 g。同时以氚质量流推导出氚自持判断条件,分析了设计参数能够满足氚自持要求,同时获得了燃烧效率、氚增殖率、提取效率与氚自持的互补关系,三者作为关键参数相互依存,于临界值、设计值、理想值之间分析了氚的自持情况。     

Analysis of isotopic signals in the Danube River water at Tulln,Austria, based on daily grab samples in 2012

Results of stable isotope measurements (δ²H, δ¹⁸O) of daily grab samples, taken from the Danube River at Tulln (river km 1963) during 2012, show seasonal and short-term variations depending on the climatic/hydrological conditions and changes in the catchment area (temperature changes, heavy rains and snow melt processes). Isotope ratios in river water clearly reflect the isotopic composition of precipitation water in the catchment area since evaporation influences play a minor role. Average δ²H and δ¹⁸O values in 2012 are?78‰ and?11.0‰, respectively, deuterium excess averages 10‰. The entire variation amounts to 1.8‰ in δ¹⁸O and 15‰ in δ²H. Quick changes of the isotopic composition within a few days emphasise the necessity of daily sampling for the investigation of hydrological events, while monthly grab sampling seems sufficient for the investigation of long-term hydro-climatic trends. ³H results show peaks (half-width 1–2 days, up to about 150 TU) exceeding the regional environmental level of about 9 TU, probably due to releases from nuclear power plants.     

The Origin and Evolution of Some Mineral Water Sources Estimated from Their Deuterium Content

In this paper are discussed the origin and the evolution of several mineral water sources from some places of Romania, on the basis of deuterium content variations of water which take place in time and their correlation with the total salt content.     

石墨炉原子吸收光谱法快速测定塑料饮水管浸出液中的痕量锑

采用铜作基体改进剂、横向塞曼扣背景石墨炉原子吸收光谱法快速测定塑料饮水管浸出液中痕量锑。对石墨炉加热程序中的灰化温度和原子化温度进行了优化 ,同时也研究了介质酸度的影响。选定了最佳测量条件 ,提高了方法的灵敏度和精密度。本方法的线性范围为 0 2 7～ 2 0 0 μg·L-1 ,工作曲线回归方程为Y=0 0 0 6 8X - 0 0 0 0 2 ,相关系数r=0 9996 ,特征质量为 6 7pg ,最低检测量为 5 4pg ,回收率在 92 2 %～1 0 2 5 %。对 5 0 ,1 0 0 ,2 0 0 μg·L-1 锑的标准溶液连续测定 6次 ,相对标准偏差分别为 6 4 7% ,4 97% ,2 4 5 %。结果表明 ,该方法简便、快速、灵敏、重现性好、准确度高 ,用于实际样品分析结果满意     

Deuterium as Natural Tracer in Groundwater from Neighbouring Area of Danube Delta Biosphere Reserve

Abstract

Measurements of deuterium content of the groundwater from neighbouring area of Danube Delta Biosphere Reserve show that the waters are meteoric in origin, but at the same time the results showed that the water for three sampling points could not originate from local groundwater and have their recharge area at high altitude and a considerable distance.

According to the δD values the following categories of waters were delineated:

• (1) waters that belong to an confined aquifer in limestone and have their recharge in high altitude region, higher than 1000m (δD < -80‰)

  (2) waters tributary to the Danube river that have a small variability in time of δD values (δD > - 75‰)
  (3) local infiltration waters, situated in the West of the investigated area towards the continental platform of the Dobroudja, with high variability in time of δD values, due to seasonal effect (δD > - 70‰)
  (4) waters originated in mixing processes between the waters with different isotopic content. The one endmember is heavier isotopic water that belongs to local recharged waters (local infiltration waters and waters tributary to Danube river) and the other endmember is the isotopically light water.

     

Use of Isotope Analysis in Solving Environmental Problems in Power Engineering

Abstract

During hydraulic dumping of ashes at a sludge bed of the power plant at Mělnik (north of Prague), new springs originated which wetted houses and properties at the small village of Podvlci. The sludge bed as well as the village lie at the southwestern margin of the alluvial plain of the Labe (Elbe) River at the foot of a slope built of Cretaceous sedimentary rocks. By analyzing the concentrations of radiocarbon and tritium, it was possible to determine the origin of the water and the ratio of the modern and original groundwater in the new springs in the surroundings of the sludge bed. To substitute the present dump the operation of which should be stopped, establishing of a new one has been proposed within the alluvial plain. By means of stable isotopes and radionuclides, the relations between the groundwater in the Quaternary sediments and in the underlying Middle Turonian confined aquifer were studied, because changes in the hydrogeological regime have to be expected due to the operation of the proposed new sludge bed.     

On Mechanism of Influence of Low Intense Millimeter Waves on Air Content in Water

The two-stage mechanism is offered, on which the millimeter waves rises concentration of free air in water. At first, millimeter waves localize heating in a volume of the sample, creating supersaturated concentration of the dissolved air in a fluid. Then superfluous air diffuses in embryonic microbubbles present in a fluid. The experimental data confirm the mechanism suggested.     

Optimized Selection of Water Resource Allocation Schemes Based on Improved Connection Entropy in Beijing’s Southern Plain

Increased urbanization has caused problems such as increasing water consumption and the continuous deterioration of the groundwater environment. It is necessary to consider the groundwater quality in the water resource optimization system and increase the rate of reclaimed water development to reduce the amount of groundwater exploitation and achieve sustainable development of water resources. This study used the Daxing District, a region of Beijing’s southern plain, as an example to evaluate water quality by analyzing water quality data of surface and groundwater from 2012 to 2016 and actual water-use schemes from 2006 to 2016. Three groundwater extraction modes were set up based on NO₃–N concentrations, water resources were optimized under three extraction modes, and water resource optimization schemes were determined based on the improved connection entropy. The results show that (1) the surface water quality was poor, and the proportion of V₄ type water in the indexes of NH₃–N and chemical oxygen demand (COD) was the largest. The surface water can only be used for agricultural irrigation. The pollution sources contributing most to NH₃–N and COD were domestic and agricultural pollution sources. (2) The groundwater quality was good. The NO₃–N index was primarily type I–III water, accounting for 95.20% of the total samples. Severe NH₃–N pollution areas were mainly in the northern region, and most regional groundwater can be used for various purposes. (3) Taking 2016 as an example, three groundwater exploitation modes were set to optimize water resource allocation, and the results showed that the rate of groundwater development and NO₃–N pollution decreased significantly after optimization. (4) Connection entropy is an evaluation method that combines connection numbers and entropy, including identify, difference, and opposition entropy. As connection entropy being a kind of complete entropy, which can reflect the difference of the system in different states, based on the improved connection entropy, the connection entropies of optimal water resource allocation and actual water-use schemes were calculated. The connection entropy of groundwater exploitation mode 3 was less than that of groundwater exploitation modes 1 and 2 and actual water-use schemes from 2006 to 2016. Therefore, exploitation mode 3’s water resource optimization scheme was recommended. In the paper, satisfactory results have been obtained. As a kind of complete entropy, connection entropy has great research value in dealing with complex hydrological problems. This study’s research methods and outcomes can provide methodological and theoretical lessons for water management in freshwater-deficient areas.     

基于高光谱特征与人工神经网络模型对土壤含水量估算

土壤含水量(θ)是影响作物生长和作物产量的主要因素之一。旨在评估基于光谱特征参数的各种回归模型估算土壤含水量的精度,并比较人工神经网络(BP-ANN)和光谱特征参数模型的性能。2014年在室内获取砂土和壤土的土壤含水量和光谱反射率数据。结果表明：(1)当砂土容重为1.40 g·cm-3时,900～970 nm最大反射率和900～970 nm反射率总和估算θ达到极显著水平(R2超过0.90);容重为1.50 g·cm-3时,用蓝边最大反射率和900～970 nm反射率总和估算θ相关性最好(超过0.70);容重为1.60 g·cm-3时,780～970 nm反射率总和与560～760 nm归一化吸收深度的R2均超过0.90,达到极显著水平;容重为1.70 g·cm-3时,900～970 nm最大反射率和900～970 nm反射率总和的R2为0.88,呈极显著水平。(2)当土壤类型为壤土时,用900～970 nm最大反射率和900～970 nm反射率总和估算θ相关性最好。(3)蓝边反射率总和(R2=0.26和RMSE=0.09 m3·m-3)和780～970 nm吸收深度(R2=0.32和RMSE=0.10 m3·m-3)估算砂土的含水量相关性最好。在估算壤土的含水量时,900～970 nm最大反射率(R2=0.92和RMSE=0.05 m3·m-3)与900～970 nm反射率总和估算模型的精度最高(R2=0. 92和RMSE=0.04 m3·m-3)。(4)用人工神经网络模型能够更好地估算两种土壤的含水量(R2=0.87和RMSE=0.05 m3·m-3)。因此,人工神经网络模型对θ估算具有巨大的潜力。     

气动雾化进样-微波等离子体炬全谱仪测定矿泉水中的Na,Mg, Ca,Li, Sr

采用微波等离子体炬(MPT)作为激发光源,通过气动雾化系统进样,循环水冷凝-浓硫酸吸水装置作为去溶系统,以Ar为等离子体工作气体,建立了氩微波等离子体炬全谱仪检测矿泉水中Na, Mg, Ca, Li和Sr等五种元素的方法。详细探究了微波功率源功率、工作气流量及载气流量等实验参数对待测元素发射信号的影响,并且对这些参数进行了优化。在优化的实验条件下,对11种瓶装饮用矿泉水进行了检测,方法对Na, Mg, Ca, Li和Sr的检出限分别为4.4,21,56,11和84 μg·mL-1,相对标准偏差范围为1.30%～5.45%(n=6),加标回收率在84.6%～98.5% 之间。实验结果表明,此装置简单便捷、分析成本低;此方法分析速度快、精确度与准确度高、能够同时测定多种元素,适用于矿泉水中元素检测,为打击非法商家提供了手段,同时也为人们的饮用水质量提供了安全保障,有望用于食品安全、药品安全、临床诊断及更多领域的分析检测。     

Spatial and temporal characteristics of stable isotopes in the Tarim River Basin

By using 233 isotope samples, we investigated the spatial and temporal variations of δ¹⁸O and δ²H in precipitation and surface water, and the contribution of different water sources in the rivers within the Tarim River Basin (TRB), which receives snow/glacier meltwater, groundwater, and rainfall. Our study revealed a similar seasonal pattern of precipitation δ¹⁸O and δ²H at both the north and south edges of the basin, indicating the dominant effect of westerly air masses in the summer and the combined influence of westerly and polar air masses during the winter, although the southern part showed more complex precipitation processes in the summer. River water in the basin has relatively large temporal variations in both δ¹⁸O and δ²H showing a distinct seasonal pattern with lower isotope values in May than in September. Higher d-excess values throughout the year in the Aksu river and the Tizinafu river suggest that water may be intensively recycled in the mountains of the TRB. Based on isotopic hydrograph separation, we found that groundwater is the main water source that discharges the entire basin although individual rivers vary.     

Application of stable isotopes and hydrochemical analysis in groundwater aquifers of Argolis Peninsula (Greece)

The present study examines the isotopic and hydrochemical composition of 18 inland spring waters and 3 coastal karstic spring waters, covering the period between October 2005 and March 2008. The stable isotopes (¹⁸O, ²H) processing has revealed the absence of significant evaporation phenomena and that the origin of fresh water samples is meteoric. Using ¹⁸O values in rainfall waters, an average line of isotopic depletion with altitude has been constructed, extracting a rate of?0.45‰/100 m as typical for the study area. Furthermore, the mean altitude of recharge of the springs has been estimated by plotting the groundwater sampling points on a δ¹⁸O versus altitude diagram. Hydrochemistry results have shown that the dissolution of carbonate, flysch and ophiolitic formations defines the hydrochemical characteristics of groundwater. Moreover, seawater intrusion in the coastal area is significantly high, causing the water in the three karstic springs to be brackish.     

Identifying local and regional groundwater in basins: chemical and stable isotopic attributes of multivariate classification of hydrochemical data,the Lower Virgin River Basin,Nevada, Arizona and Utah,U.S.A

In the Basin and Range Province of the Southwestern U.S.A., deep carbonate groundwater has been suggested as a significant source to many overlying basin-fill alluvial aquifer systems. Notwithstanding, testing this hypothesis is limited by obtaining data from such considerable depths and complex geology.

This study uses δ²H and δ¹⁸O data from springs, rivers, and wells tapping shallow basin-fill groundwater to test the hydrochemical interpretation of deep regional carbonate groundwater flow into the basin-fill aquifers. Stable isotopic and major ion attributes of hydrochemical facies suggest basin-fill alluvial groundwater of the Lower Virgin River Basin is a mixture of precipitation recharge within the Lower Virgin River Basin or the Clover and Escalante Desert Basin northwards, and the deep carbonate flow. The data support the conclusions that in the Lower Virgin River Basin, deep carbonate groundwater is an important source to the alluvial aquifer system and likely accounts for approximately 50% of the alluvial aquifer groundwater. Na⁺, K⁺, and SO₄^2– increase in the basin-fill alluvial groundwaters outside the Virgin River floodplain appears to be related with upwelling of deep regional groundwater, and indicating that the chemical character of the basin-fill alluvial groundwaters are related to the deeper flow systems.     

基于光谱分析与角度斜率指数的植被含水量研究

植被含水量是植被生长状态的重要指示因子,是农业、生态和水文等研究中的重要参数,其诊断对于监测自然植被群落的干旱状况、预报森林火灾等都具有重要意义。通过对植被光谱反射率与植被含水量的相关性分析,发现植被波谱不同波段的光谱反射率与植被含水量的相关性差异很大,其中可见光红光波段(620～700 nm)、近红外波段(800～1 350, 1 600～1 950, 2 200～2 400 nm)的光谱反射率与植被含水量具有较好的相关性,选取了660,850,1 630和2 200 nm的光谱反射率作为RED,NIR,SWIR1和SWIR2的波段值来建立角度斜率指数;分析了植被含水量与角度斜率指数的关系,将角度斜率指数(SANI,SASI,ANIR)作为反演植被含水量的参量,建立植被含水量与角度斜率指数之间线性回归模型。通过对近红外角度指数ANIR改进,提出了近红外角度归一化指数NANI(near infrared angle normalized index)与近红外角度斜率指数NASI(near infrared angle slope index),建立植被含水量与NANI和NASI之间线性回归模型,结果显示：NANI与Palacios-Orueta等提出的角度斜率指数(SANI,SASI,ANIR)相比有一定的优势,模型可决系数R2从原最高0.791提高到0.853,RMSE也从原最小0.047降低到0.039。确定了NANI为反演植被含水量的最佳角度斜率指数,并建立了植被含水量反演模型。该研究主要创新点：在前人研究成果基础上,通过对原角度斜率指数的改进,提出了NANI和NASI角度斜率指数,使其在植被含水量反演上具有更高的精度。     

基于灰色关联法的春小麦叶片含水量高光谱估测模型研究

利用高光谱植被指数反演植被水分含量时,快速、准确的找到实测光谱数据与植被水分相关性最高的植被指数是研究的重点。在农田尺度上,以春小麦野外光谱数据与叶片含水量的定量关系为基础,通过灰色关联度分析,筛选出与叶片含水量灰色关联度较高的5种典型的水分植被指数,并建立了估算春小麦叶片含水量(LWC)的偏最小二乘回归(PLSR)模型和BP神经网络(back propagation artificial neural networks, BP ANN)模型。结果表明：(1)光谱一阶导数可以有效去除噪声影响并突出光谱特征信息,尤其是在750～830,1 000～1 060和2 056～2 155 nm等区间明显提高了与LWC的相关性。(2)灰色关联法能够较好的表征各水分植被指数与叶片含水量间的关联性,其中基于原始光谱建立的前5个水分植被指数都是两波段比值植被指数,基于光谱一阶导数建立的水分植被指数基本上都是两波段归一化差值植被指数。(3)所建立的两种模型中,基于光谱一阶导数建立的PLSR和BP神经网络模型R2分别为0.80和0.81,稳定性基本相同且都较好;两种模型RMSE都是0.55,RPD分别为2.01和1.41,说明PLSR模型的预测精度比BP神经网络模型高。从模型的验证效果来看,PLSR模型在估算春小麦叶片含水量方面有一定的优势,为高光谱定量反演春小麦叶片含水量提供一定的参考。