scholarly journals Calculating groundwater mixing ratios in multi-aquifers based on statistical methods: a case study

Author(s):  
Song Chen ◽  
Herong Gui

Abstract Samples of river water and groundwater from Quaternary (QA), sandstone (SA), Taiyuan formation (TA), and Ordovician limestone (OA) aquifers in the Suxian coal-mining district, Anhui Province, China were collected. Their physicochemical properties, and major ion and isotopic compositions were determined. The samples were alkaline, with pH values exceeding 8, and the total dissolved solids concentrations depended on the water source. The δD and δ18O contents were highest in the river water samples and lowest in the SA groundwater. The isotopic characteristics of the QA and OA groundwaters suggest recharge by rainfall and surface water. The isotopic characteristics of river water were controlled mainly by evaporation. Water–rock interactions, the flow rate, and the main water sources were the most important influences on groundwaters in QA, OA, and TA, but the properties of SA groundwater were controlled by static reserves. Two discriminant functions, explaining more than 98.2% of the total variances, indicated that QA, TA, and OA were hydraulically connected. Three groundwater sources were identified as end-members, and a conceptual model was established to calculate water mixing ratios.

2014 ◽  
Vol 9 (2) ◽  
pp. 158-164
Author(s):  
Linhua Sun ◽  
Jinmu Fu ◽  
Sheng Zhang

Water in river is important for human beings. For better understanding the variations of nitrate concentrations in five main rivers in northern Anhui Province, China, the NH4+-N concentrations of the 168 river water samples collected during 2010 have been analyzed by probability graph. The results indicate that the concentrations of NH4+-N vary significantly, which implying the multi contributions of nitrate in the river. In comparison with the water quality standards of China, most of the samples (76.6%) can be used for agricultural and industrial purpose, and more than half of the samples (53.6%) can be used for drinking purpose. Moreover, probability plots, in combination with quantile and density plots have subdivided the concentrations of NH4+-N into five populations with four thresholds (0.28, 0.70, 1.64 and 6.14 mg/l), the concentrations <0.28 and 1.64 mg/l are considered to be representative of pristine and current environmental background, respectively, and concentrations >1.64 mg/l are considered to be representative of anthropogenic pollution.


2016 ◽  
Vol 11 (1) ◽  
pp. 219-227
Author(s):  
Song Chen

Eighteen river- and two ground- water samples were collected on Huaibei plain. The major ions, and hydrogen and oxygen isotope concentrations were determined, and statistical and other analyses carried out. The results showed that all of the waters are alkaline, with high Total Dissolved Solids (TDS) concentrations. Na+ + K+, and SO42− + HCO3− are the dominant anionic and cationic species, respectively, and the waters are mainly Na·K-SO4 and Na·K-HCO3 types. The δD and δ18O in river waters ranged from −53.07‰ to −22.07‰ and −6.97‰ to −1.23‰, with average values of −38.30‰ and −4.09‰, respectively. The δD and δ18O concentrations in groundwater were lower than in the river water samples. The correlation between δD and δ18O concentrations in the river water can be described by the formula δD = 5.32*δ18O − 16.54, which can also be considered the local evaporation line. The ionic content and character of the river water is mainly controlled by precipitation, evaporation and carbonate weathering, as deduced from the Gibbs diagram and principal component analyses.


2015 ◽  
Vol 8 (1) ◽  
pp. 38-42
Author(s):  
Pengfei Si ◽  
Xiangyang Rong ◽  
Angui Li ◽  
Xiaodan Min ◽  
Zhengwu Yang ◽  
...  

As a realization of the energy cascade utilization, the regional energy system has the significant potential of energy saving. As a kind of renewable energy, river water source heat pump also can greatly reduce the energy consumption of refrigeration and heating system. Combining the regional energy and water source heat pump technology, to achieve cooling, heating and power supply for a plurality of block building is of great significance to reduce building energy consumption. This paper introduces a practical engineering case which combines the regional energy system of complex river water source heat pump, which provides a detailed analysis of the hydrology and water quality conditions of the river water source heat pump applications, and discusses the design methods of water intake and drainage system. The results show that the average temperature of cold season is about 23.5 °C, the heating season is about 13.2 °C; the abundant regional water flow can meet the water requirement of water source heat pump unit; the sediment concentration index cannot meet the requirement of river water source heat pump if the water enters the unit directly; the river water chemistry indicators (pH, Cl-, SO42-, total hardness, total iron) can meet the requirement of river water source heat pump, and it is not required to take special measures to solve the problem. However, the problem of sediment concentration of water must be solved.


2012 ◽  
Vol 66 (5) ◽  
pp. 1103-1109 ◽  
Author(s):  
Zenghu Qin ◽  
Mingwei Tong ◽  
Lin Kun

Due to the surface water in the upper reaches of Yangtze River in China containing large amounts of silt and algae, high content of microorganisms and suspended solids, the water in Yangtze River cannot be used for cooling a heat pump directly. In this paper, the possibility of using Yangtze River, which goes through Chongqing, a city in southwest China, as a heat source–sink was investigated. Water temperature and quality of the Yangtze River in the Chongqing area were analyzed and the performance of water source heat pump units in different sediment concentrations, turbidity and algae material conditions were tested experimentally, and the water quality standards, in particular surface water conditions, in the Yangtze River region that adapt to energy-efficient heat pumps were also proposed. The experimental results show that the coefficient of performance heat pump falls by 3.73% to the greatest extent, and the fouling resistance of cooling water in the heat exchanger increases up to 25.6% in different water conditions. When the sediment concentration and the turbidity in the river water are no more than 100 g/m3 and 50 NTU respectively, the performance of the heat pump is better, which can be used as a suitable river water quality standard for river water source heat pumps.


Minerals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 582
Author(s):  
Magner Turner-Carrión ◽  
Paúl Carrión-Mero ◽  
Israel Turner-Salamea ◽  
Fernando Morante-Carballo ◽  
Maribel Aguilar-Aguilar ◽  
...  

The Zaruma-Portovelo mining district in Ecuador, and in particular, Portovelo City, is home to the oldest mining museum in the country. This museum, named Museo Mineralógico Magner Turner (MMMT in Spanish), is a centre that reflects, through its collections, the history and culture of this territory. This work aimed to evaluate the MMMT as a possible geosite by analysing its contributions to the geomining heritage of the Zaruma-Portovelo district, and thus, to enhance it and promote its collections as a geotouristic attraction. The work involved three phases: (i) describing the museum and its surroundings; (ii) a semiquantitative evaluation of the museum using the Brilha method and a geosites assessment model (GAM); and (iii) a qualitative evaluation using the Delphi and SWOT methodologies to define strategies and proposals for museum development. The results obtained by the semiquantitative evaluation of the geosite with the Brilha method reflect high scientific (330/400), educational (380/400) and touristic (365/400) appeal. The applied GAM shows the museum as a geosite with high principal and additional value, placing it in the Z33 field of the global valuation matrix. In addition, the semiquantitative and qualitative evaluation made it possible to describe the importance of the museum and its collections in the development of the area. The study carried out qualified the museum as a mining site with an appropriate valuation, an example of ex-situ geological heritage conservation and a basis for geotourism development.


2021 ◽  
Vol 9 (8) ◽  
pp. 839
Author(s):  
Tarek N. Salem ◽  
Nadia M. Elkhawas ◽  
Ahmed M. Elnady

The erosion of limestone and calcarenite ridges that existed parallel to the Mediterranean shoreline forms the calcareous sand (CS) formation at the surface layer of Egypt's northern coast. The CS is often combined with broken shells which are considered geotechnically problematic due to their possible crushability and relatively high compressibility. In this research, CS samples collected from a site along the northern coast of Egypt are studied to better understand its behavior under normal and shear stresses. Reconstituted CS specimens with different ratios of broken shells (BS) are also investigated to study the effect of BS ratios on the soil mixture strength behavior. The strength is evaluated using laboratory direct-shear and one-dimensional compression tests (oedometer test). The CS specimens are not exposed to significant crushability even under relatively high-stress levels. In addition, a 3D finite element analysis (FEA) is presented in this paper to study the degradation offshore pile capacity in CS having different percentages of BS. The stress–strain results using oedometer tests are compared with a numerical model, and it gave identical matching for most cases. The effects of pile diameter and embedment depth parameters are then studied for the case study on the northern coast. Three different mixing ratios of CS and BS have been used, CS + 10% BS, CS + 30% BS, and CS + 50% BS, which resulted in a decrease of the ultimate vertical compression pile load capacity by 8.8%, 15%, and 16%, respectively.


Talanta ◽  
2021 ◽  
Vol 226 ◽  
pp. 122130
Author(s):  
Gilberto J. Silva Junior ◽  
Jéssica Soares Guimarães Selva ◽  
Anandhakumar Sukeri ◽  
Josué M. Gonçalves ◽  
Matias Regiart ◽  
...  

2010 ◽  
Vol 25 (6) ◽  
pp. 1376-1381 ◽  
Author(s):  
Noelia A. Martínez ◽  
Rudolf J. Schneider ◽  
Germán A. Messina ◽  
Julio Raba

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