Hydro-geochemical and isotopic characterization of the deep groundwater from coal bearing in Mining district, Northern Anhui Province, China

2013 ◽  
Vol 8 (3-4) ◽  
pp. 330-341 ◽  
Author(s):  
Song Chen ◽  
He Rong Gui ◽  
Lin Hua Sun

Hydro-geochemistry and isotopes were used to understand the geochemical character and origin of the groundwater from coal bearing aquifer in Northern Anhui province, China. Twenty three groundwater samples were collected, and the isotopic composition δD, δ18O and major ions were analyzed, conventional graphical and multivariate statistical approach was completed and the result showed: three groups of groundwater could be divided form the rectangular field, the Ca-Mg-Cl, Na-Cl-SO4 and Na-HCO3 type water; the feldspar weathering is dominating weathering process, whereas, the sulfuric acid is the weathering agent along with the carbonic acid; the groundwater mainly supplied from the meteoric water for all the plots are below the local meteoric water line and global meteoric water line, the values of δD are drifted obviously, what could be caused by the exchange reaction of δD between groundwater and alkyl.

2013 ◽  
Vol 17 (7) ◽  
pp. 2917-2928 ◽  
Author(s):  
G. Mongelli ◽  
S. Monni ◽  
G. Oggiano ◽  
M. Paternoster ◽  
R. Sinisi

Abstract. Throughout the Mediterranean, salinization threatens water quality, especially in coastal areas. This salinization is the result of concomitant processes related to both seawater intrusion and water–rock interaction, which in some cases are virtually indistinguishable. In the Nurra region of northwestern Sardinia, recent salinization related to marine water intrusion has been caused by aquifer exploitation. However, the geology of this region records a long history from the Palaeozoic to the Quaternary, and is structurally complex and comprises a wide variety of lithologies, including Triassic evaporites. Determining the origin of the saline component of the Jurassic and Triassic aquifers in the Nurra region may provide a useful and more general model for salinization processes in the Mediterranean area, where the occurrence of evaporitic rocks in coastal aquifers is a common feature. In addition, due to intensive human activity and recent climatic change, the Nurra has become vulnerable to desertification and, in common with other Mediterranean islands, surface water resources periodically suffer from severe shortages. With this in mind, we report new data regarding brackish and surface waters (outcrop and lake samples) of the Na-Cl type from the Nurra region, including major ions and selected trace elements (B, Br, I, and Sr), in addition to isotopic data including δ18O, δD in water, and δ34S and δ18O in dissolved SO4. To identify the origin of the salinity more precisely, we also analysed the mineralogical and isotopic composition of Triassic evaporites. The brackish waters have Cl contents of up to 2025 mg L−1 , and the ratios between dissolved ions and Cl, with the exception of the Br / Cl ratio, are not those expected on the basis of simple mixing between rainwater and seawater. The δ18O and δD data indicate that most of the waters fall between the regional meteoric water line and the global meteoric water line, supporting the conclusion that they are meteoric in origin. A significant consequence of the meteoric origin of the Na-Cl-type water studied here is that the Br / Cl ratio, extensively used to assess the origin of salinity in fresh water, should be used with care in carbonate aquifers that are near the coast. Overall, δ34S and δ18O levels in dissolved SO4 suggest that water–rock interaction is responsible for the Na-Cl brackish composition of the water hosted by the Jurassic and Triassic aquifers of the Nurra, and this is consistent with the geology and lithological features of the study area. Evaporite dissolution may also explain the high Cl content, as halite was detected within the gypsum deposits. Finally, these Na-Cl brackish waters are undersaturated with respect to the more soluble salts, implying that in a climate evolving toward semi-arid conditions, the salinization process could intensify dramatically in the near future.


2018 ◽  
Vol 69 (8) ◽  
pp. 1290 ◽  
Author(s):  
Mohammed Bahir ◽  
Salah Ouhamdouch ◽  
Paulà M. Carreira

Study of the Cenomanian–Turonian and Plio–Quaternary aquifers of Essaouira basin (Western Morocco), based on the interpretation of geochemical (major elements) and isotopic (18O, 2H, 13C and 14C) data, has aided the understanding of the hydrodynamics of these aquifers, which is greatly affected by tectonics. Hydrochemical characteristics based on the bivariate diagrams of major ions (Cl–, SO42–, NO3–, HCO3–, Na+, Mg2+, K+ and Ca2+) and electrical conductivity and mineral saturation indices indicate that the origins of groundwater mineralisation are the result of: (1) evaporite dissolution; (2) cation exchange reactions; (3) and evaporation processes. Radiogenic isotopes (3H and 14C) have highlighted the presence of significant recent recharge in the eastern part of the basin, with groundwater moving according to the general flow path (south-east to north-west). Stable isotope data from the Essaouira basin plot along the Global Meteoric Water Line and below the Local Meteoric Water Line. This suggests that groundwater has been recharged under several different climate regimes.


Author(s):  
Lorenza Li Vigni ◽  
Kyriaki Daskalopoulou ◽  
Sergio Calabrese ◽  
Konstantinos Kyriakopoulos ◽  
Francesco Parello ◽  
...  

AbstractGeothermal areas of Greece are located in regions affected by recent volcanism and in continental basins characterised by elevated heat flow. Many of them are found along the coast, and thus, water is often saline due to marine intrusion. In the current study, we present about 300 unpublished and literature data from thermal and cold mineral waters collected along Greece. Samples were analysed for major ions, Li, SiO2 and isotopes in water. Measured temperatures range from 6.5 to 98 °C, pH from 1.96 to 11.98, while Total Dissolved Solutes (TDS) from 0.22 to 51 g/L. Waters were subdivided into four main groups: (1) thermal; (2) cold; (3) acidic (pH < 5); and (4) hyperalkaline (pH > 11). On statistical basis, thermal waters were subdivided into subgroups according to both their temperature [warm (< 29 °C), hypothermal (29–48 °C), thermal (48–75 °C) and hyperthermal (> 75 °C)] and TDS [low salinity (< 4 g/L), brackish (4–30 g/L) and saline (> 30 g/L)]. Cold waters were subdivided based on their pCO2 [low (< 0.05 atm), medium (0.05–0.85 atm) and high (> 0.85 atm)]. δ18O–H2O ranges from − 12.7 to + 2.7‰ versus SMOW, while δ2H–H2O from − 91 to + 12‰ versus SMOW being generally comprised between the Global Meteoric Water Line and the East Mediterranean Meteoric Water Line. Positive δ18O shifts with respect to the former are mostly related to mixing with seawater, while only for a few samples these shifts point to high-temperature water–rock interaction processes. Only a few thermal waters gave reliable geothermometric estimates, suggesting reservoir temperatures between 80 and 260 °C.


Water ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 1927
Author(s):  
Limbikani C. Banda ◽  
Michael O. Rivett ◽  
Anold S. K. Zavison ◽  
Sydney Kamtukule ◽  
Robert M. Kalin

With the resurgence of water-isotope tracing applications for Integrated Water Resource Management in developing countries, establishing a stable isotopic baseline is necessary. Developing countries, including Malawi, continue to struggle with the generation of consistent and long-term isotopic datasets due to non-existent or inadequate in-country water-isotope capacity. Malawi has made significant advances in its quest to establish a stable isotopic baseline through the establishment of the Malawi Network of Isotope in Precipitation. This study provides the first results for the isotopic characterization of precipitation in Malawi with a view to reinforcing understanding of the country’s hydrological cycle. Error-in-variables regression defined a Local Meteoric Water Line as δ2H = 8.0 (±0.3) δ18O + 13.0 (±2.0) using stable isotopic records of 37 monthly samples from 5 stations between 2014 and 2019. Local precipitation (isotopic composition) is consistent with global precipitation expectations, its condensation-forming process occurring under equilibrium conditions and a higher intercept (d-excess) above the 10‰ for Global Meteoric Water Line, implying that air moisture recycling significantly influences local precipitation. Wider variations observed in local precipitation isotopic signatures are largely attributed to different moisture-bearing systems and diverse geographic factors across the country. Additional stations are recommended to improve spatial coverage that, together with longer temporal records, may help understanding and resolving uncertainties such as the altitude effect. This pioneering study is expected to facilitate Malawi’s ambition to achieve integrated use and improved protection of its surface water and groundwater resources in response to mounting climate change, growing population and land-development concerns.


2014 ◽  
Vol 9 (1) ◽  
pp. 95-103 ◽  
Author(s):  
He Rong Gui

Major ions, trace elements and isotope concentrations for eight groundwater samples were tested, which collected from sandstone aquifer in Qianyingzi mine, northern Anhui province, China. The Geochemical characteristic of groundwater samples were studied based on the conventional graphical and multivariate statistical approach, and the resulted showed: two types of groundwater could be identified through the Piper diagram, which have high concentrations total dissolved solids (1,164–5,165 mg/L), with alkaline environment (pH = 8.02–8.90) in nature; the rare earth element of groundwater samples are characterized by enrichment of HREEs compared to LREEs when normalized to PAAS, which presented from the NdSN/YbSN ratios ranging from 0.042 to 0.121, with an average 0.075; groundwater characterized by negative Ce anomalies and positive Eu anomalies, what could be caused by the Ph conditions and exchange reaction between Eu2+ and Sr2+, respectively; δ18O and δ2H of groundwater varied from −8.78 to −8.36‰ and −68.5 to −59.5‰, respectively. The detritus and the exchange reaction between groundwater and alkyl could be the reason of obviously drift of δ2H.


2013 ◽  
Vol 8 (1) ◽  
pp. 131-141 ◽  
Author(s):  
Song Chen ◽  
Xue Hai Fu ◽  
He Rong Gui ◽  
Lin Hua Sun

Major ions were analyzed for twenty five groundwater samples collected from diverse aquifer in Baishan mining, northern Anhui province, China. Conventional graphical and multivariate statistical approach were completed to identify the hydro-geochemical process and water-rock interaction, that be combined with the Cluster Analysis (CA) and Fisher discriminant analysis to recognize the sealed samples, the result showed: the diverse samples have vary ions inheriting from aquifer, samples collected from Sandstone aquifer (SA) is characterized by the high concentration of Na+ + K+, for the feldspar weathering is dominant; Ordovician limestone aquifer (OA) waters have abundance Ca2+ and Mg2+, for the dissolution of calcite and dolomite obviously; the dissolution of calcite and other calcareous concretions are dominant in Taiyuan formation water (TA) and Quaternary aquifer (QA) for the high ratio of Ca2+/Mg2+, otherwise the varied content of SO42– and HCO3− could distinguish the two aquifer water. Twenty five groundwater samples, containing six sealed samples, had been subdivided in to four groups by the CA, what are corresponded with four aquifers. Fisher discriminant functions were obtained and the efficiency was acceptable for the error rate 4% in all twenty five samples.


Water ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2791
Author(s):  
Pengyan Su ◽  
Mingjun Zhang ◽  
Deye Qu ◽  
Jiaxin Wang ◽  
Yu Zhang ◽  
...  

As a species for ecological restoration in northern China, Tamarix ramosissima plays an important role in river protection, flood control, regional climate regulation, and landscape construction with vegetation. Two sampling sites were selected in the hillside and floodplain habitats along the Lanzhou City, and the xylems of T. ramosissima and potential water sources were collected, respectively. The Bayesian mixture model (MixSIAR) and soil water excess (SW-excess) were applied to analyze the relationship on different water pools and the utilization ratios of T. ramosissima to potential water sources in two habitats. The results showed that the slope and intercept of local meteoric water line (LMWL) in two habitats were smaller compared with the global meteoric water line (GMWL), which indicated the existence of drier climate and strong evaporation in the study area, especially in the hillside habitat. Except for the three months in hillside, the SW-excess of T. ramosissima were negative, which indicated that xylems of T. ramosissima are more depleted in δ2H than the soil water line. In growing seasons, the main water source in hillside habitat was deep soil water (80~150 cm) and the utilization ratio was 63 ± 17% for T. ramosissima, while the main water source in floodplain habitat was shallow soil water (0~30 cm), with a utilization ratio of 42.6 ± 19.2%, and the water sources were different in diverse months. T. ramosissima has a certain adaptation mechanism and water-use strategies in two habitats, and also an altered water uptake pattern in acquiring the more stable water. This study will provide a theoretical basis for plant water management in ecological environment protection in the Loess Plateau.


Author(s):  
Yang Song ◽  
Shengjie Wang ◽  
Athanassios Argiriou ◽  
Mingjun Zhang ◽  
Yudong Shi

The stable hydrogen and oxygen isotopes as well as their correlation in precipitation have been widely investigated for the understanding of various hydrological processes. Monthly precipitation data were usually recommended in order to establish a linear relationship between the stable hydrogen and oxygen isotope ratios (also known as local meteoric water lines or LMWL for a specific location); however, the LMWL based on daily (or event-based) precipitation data is usually different from that using monthly data. Based on 83 sampling stations across the world from 2000 to 2017, local meteoric water lines were calculated using daily (or event-based) precipitation data (n=9354) and corresponding monthly data (n=1895), respectively; multiple regression methods were used, including ordinary least squares, reduced major axis and major axis regressions as well as their precipitation-weighted counterparts. The global meteoric water line from daily data is δ2H = (7.72 ± 0.02) δ18O + (6.84 ± 0.15) (n=9354, r2=0.96) and from monthly data is δ2H = (7.81 ± 0.04) δ18O+(7.61 ± 0.32) (n=1895, r2=0.96). The stations used in this study were grouped into five climate types, according to the Köppen Climate classification. The precipitation-weighted regression may increase the long-term receptiveness of LMWL using daily-based (or event-based) samples, not only for arid regions, but also for cold regions. When only relatively short-term isotopic records in event-based precipitation samples are available, which is usual in modern hydrological studies, the weighted regression (especially precipitation weighted ordinary least squares regression, PWLSR) is helpful to create a respective local meteoric water line.


2012 ◽  
Vol 60 (4) ◽  
pp. 265-276 ◽  
Author(s):  
Ladislav Holko ◽  
Michal Dóša ◽  
Juraj Michalko ◽  
Martin Šanda

The article synthesizes available information on isotopic composition of precipitation in Slovakia (the Western Carpathians). Monthly δ18O data from eleven stations and period 1988-1997 were used to investigate correlations among the stations, altitude, air temperature and precipitation amount effects. The mean annual altitude and air temperature gradients of δ18O in precipitation were 0.21‰/100 m and 0.36‰/1°C, respectively. Maps of spatial distribution of mean annual δ18O in precipitation based on both gradients were constructed. The two maps do not significantly differ for the majority of Slovakia. δ2H data were available for only three stations. Local meteoric water line derived for the station with the longest data series (δ2H = = 7.86δ18O + 6.99) was close to the Global Meteoric Water line. Its parameters in periods 1991-1993 and 1991-2008 did not change. The study indicates that a more detailed monitoring of isotopic composition of precipitation in mountains should be carried out in the future. The highest station exhibited very small seasonal variability of δ18O in precipitation compared to other Slovak stations. The second highest mountain station had significantly higher deuterium excess than the neighboring stations located in the valley. In some analyses the data from the nearest stations situated abroad (Vienna, Krakow) were used.


Sign in / Sign up

Export Citation Format

Share Document