scholarly journals Hydrochemical Changes and Influencing Factors in the Dongkemadi Region, Tanggula Range, China

Water ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1856
Author(s):  
Tianding Han ◽  
Yuping Li ◽  
Jia Qin ◽  
Xiangying Li ◽  
Qin Yang ◽  
...  
Keyword(s):  
River Water ◽  
Chemical Weathering ◽  
River Flow ◽  
Major Ions ◽  
Meteorological Data ◽  
Atmospheric Precipitation ◽  
Dilution Effect ◽  
Ion Concentration ◽  
Rock Interaction ◽  
Geochemical Model

In order to detect the source and controlling factors of hydrochemical ions in glacier meltwater-recharged rivers, the chemical characteristics of the river water, precipitation, and meltwater of the Dongkemadi River Basin, China, in 2014 (from May to October) were systematically analyzed, and combined with the hydrological and meteorological data. The results show that the hydrochemical pattern of the typical river was HCO3−-Ca2+. The most cations were Ca2+ and Mg2+, and the predominant anions were HCO3− and SO42−, in the river. The concentration of major ions and total dissolved solids (TDS) in the river water were much larger than that in the precipitation and meltwater. The TDS concentration was ordered: River water > precipitation > meltwater. The water-rock interaction and the dilution effect of the precipitation and meltwater on the runoff ions resulted in a negative correlation between the ion concentration of the river water and the river flow. The chemical ions of the river runoff mainly originated from rock weathering and the erosion (abrasion) caused by glacier movement. In addition, the contributions of different sources to the dissolved components of the Dongkemadi River were ordered: Carbonate (75.8%) > silicate (15.5%) > hydatogenic rock (5.7%) > atmospheric precipitation (3%), calculated by a forward geochemical model. And the hydrochemical weathering rates of carbonate and silicate minerals were 12.30 t·km−2·a−1 and 1.98 t·km−2·a−1, respectively. The CO2 fluxes, consumed by the chemical weathering of carbonate and silicate, were 3.28 × 105 mol·km−2·a−1 and 0.91 × 105 mol·km−2·a−1, respectively.

Geochemical processes affecting the major ion composition of rivers in the South Island, New Zealand

1999 ◽  
Vol 50 (7) ◽  
pp. 699 ◽  
Author(s):  
Jonathan P. Kim ◽  
Keith A. Hunter ◽  
Malcolm R. Reid
Keyword(s):  
New Zealand ◽  
River Water ◽  
Major Ions ◽  
Geochemical Processes ◽  
Ion Composition ◽  
The South ◽  
Atmospheric Input ◽  
Geochemical Model ◽  
River Waters ◽  
Major Ion

The major ion (Na+ , K+ , Mg2+ , Ca2+ , Cl− , SO42− and reactive SiO2 ) compositions of seven rivers in the South Island, New Zealand (Manuherikia, Clutha, Takaka–Cobb, Haast, Grey, Aorere and Rakaia rivers) are reported. All the rivers were pristine in comparison with global average river waters, and the concentrations of most major ions were close to the 1% percentile levels for global river water compositions. A geochemical model that attributes ion compositions to both rain input and to the weathering of various simple mineral types in the catchment was applied to these data, and to data already published. This model, although simplistic, accounts for the main features of major ion composition in the rivers studied. The dominant sources of major ions were the weathering of limestones and feldspars. Atmospheric input was relatively small except for Na+ and Cl− .

scholarly journals Hydrochemical Characteristics and Controlling Factors of Typical Dolomite Karst Basin in Humid Subtropical Zone

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Shizhen Xiao ◽  
Cheng Zeng ◽  
Jiacheng Lan ◽  
Yongning Di ◽  
Jianghu He ◽  
...  
Keyword(s):  
Basic Research ◽  
Dilution Effect ◽  
Ion Concentration ◽  
Karst Area ◽  
Hydrochemical Characteristics ◽  
Rock Interaction ◽  
Subtropical Zone ◽  
Heritage Site ◽  
Low Concentrations ◽  
Water Rock Interaction

The hydrochemical characteristics and variation rules of water in karst areas are important for the basic research of karst field. Because only a few researches focused on the hydrochemical characteristics of humid subtropical dolomite karst basins in the past, the Shanmuhe Basin and its subbasin Huangzhouhe Basin in Shibing Dolomite Karst World Natural Heritage Site in China were selected as the study area. A total of 215 water samples were collected and analyzed. It was found that the hydrochemical type of subtropical dolomite karst basin is HCO3-Ca·Mg type, which is different from that in limestone areas and shale districts, which is HCO3-Ca type for both; EC, Ca2+, Mg2+, HCO3-, Mg2+/Ca2+, and Mg2+/HCO3- have similar spatial variations, which are lower in allogenic water in the upstream in the northwest of the basin and become higher when the water enters the dolomite karst area in the mid and downstream of the basin, and SIC and SID of the allogenic water in the upstream are below zero, while those become saturated after entering the dolomite area in the mid and downstream; the monthly variation of hydrochemistry shows that the seasonal variation of ion concentration is not obvious, and there is a dilution effect in rainy seasons, but the variation of ion concentration is small and relatively stable; higher HCO3- concentration and Mg2+/Ca2+ in the pure dolomite basin are higher than those in the impure dolomite basin; the main influencing factors of the hydrochemical features are geological background especially the lithology, and the water chemistry is mainly controlled by rock weathering and water-rock interaction; rainfall import is low and the low concentrations of K+, Na+, NO3-, Cl-, and SO42- in water indicate that human activities have little effect on the hydrochemistry in the study area.

scholarly journals Hydrochemical composition and potentially toxic elements in the Kyrgyzstan portion of the transboundary Chu-Talas river basin, Central Asia

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Long Ma ◽  
Yaoming Li ◽  
Jilili Abuduwaili ◽  
Salamat Abdyzhapar uulu ◽  
Wen Liu
Keyword(s):  
Central Asia ◽  
Human Health ◽  
River Water ◽  
River Basin ◽  
Toxic Elements ◽  
River Flow ◽  
Major Ions ◽  
Water Quality Assessment ◽  
Potentially Toxic Elements ◽  
Hydrochemical Composition

Abstract Water chemistry and the assessment of health risks of potentially toxic elements have important research significance for water resource utilization and human health. However, not enough attention has been paid to the study of surface water environments in many parts of Central Asia. Sixty water samples were collected from the transboundary river basin of Chu-Talas during periods of high and low river flow, and the hydrochemical composition, including major ions and potentially toxic elements (Zn, Pb, Cu, Cr, and As), was used to determine the status of irrigation suitability and risks to human health. The results suggest that major ions in river water throughout the entire basin are mainly affected by water–rock interactions, resulting in the dissolution and weathering of carbonate and silicate rocks. The concentrations of major ions change to some extent with different hydrological periods; however, the hydrochemical type of calcium carbonate remains unchanged. Based on the water-quality assessment, river water in the basin is classified as excellent/good for irrigation. The relationship between potentially toxic elements (Zn, Pb, Cu, Cr, and As) and major ions is basically the same between periods of high and low river flow. There are significant differences between the sources of potentially toxic elements (Zn, Pb, Cu, and As) and major ions; however, Cr may share the same rock source as major ions. The risk assessment revealed low non-carcinogenic and carcinogenic risks for human health; however, the maximum carcinogenic risk for As exceeded the allowable value, which requires further consideration. These results provide a scientific basis for the management of agricultural irrigation uses and also infill existing gaps regarding the hydrochemical composition in the Chu-Talas river basin, Central Asia.

scholarly journals Water Quality and Hydrogeochemical Characteristics of Some Karst Water Sources in Apuseni Mountains, Romania

Water ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 857
Author(s):  
Maria-Alexandra Hoaghia ◽  
Ana Moldovan ◽  
Eniko Kovacs ◽  
Ionut Cornel Mirea ◽  
Marius Kenesz ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Chemistry ◽  
Major Ions ◽  
Anthropogenic Activities ◽  
Water Sources ◽  
Main Process ◽  
Karst Water ◽  
Rock Interaction ◽  
Apuseni Mountains ◽  
Karst Waters

Human activities and natural factors determine the hydrogeochemical characteristics of karst groundwaters and their use as drinking water. This study assesses the hydrogeochemical characteristics of 14 karst water sources in the Apuseni Mountains (NW Romania) and their potential use as drinking water sources. As shown by the Durov and by the Piper diagrams, the chemical composition of the waters is typical of karst waters as it is dominated by HCO3− and Ca2+, having a circumneutral to alkaline pH and total dissolved solids ranging between 131 and 1092 mg L−1. The relation between the major ions revealed that dissolution is the main process contributing to the water chemistry. Limestone and dolostone are the main Ca and Mg sources, while halite is the main Na and Cl source. The Gibbs diagram confirmed the rock dominance of the water chemistry. The groundwater quality index (GWQI) showed that the waters are of excellent quality, except for two waters that displayed medium and good quality status. The quality of the studied karst waters is influenced by the geological characteristics, mainly by the water–rock interaction and, to a more limited extent, by anthropogenic activities. The investigated karst waters could be exploited as drinking water resources in the study area. The results of the present study highlight the importance of karst waters in the context of good-quality water shortage but also the vulnerability of this resource to anthropogenic influences.

Studies on soil reaction: III. The determination of the hydrogenion concentration of soil suspensions by means of the hydrogen electrode

1925 ◽  
Vol 15 (2) ◽  
pp. 201-221 ◽  
Author(s):  
Edward M. Crowther
Keyword(s):  
Dilution Effect ◽  
Ion Concentration ◽  
Soil Reaction ◽  
Neutral Salt ◽  
Alkaline Soils ◽  
Hydrogen Electrode ◽  
Hydrogen Ion Concentration ◽  
Base Exchange ◽  
Buffer Action ◽  
Hydrogenion Concentration

A hydrogen electrode apparatus for soils is described. Similar or adjacent soils may show considerable differences inpH value, with no changes in their degrees of buffer action, as shown in titration curves with lime water. In such cases the conventional “lime requirements” are correlated with thepH values, but no such relation holds in dissimilar soils. ThepH value of a soil suspension is intimately connected with the nature and amount of the cations present. Neutral salts markedly increase the hydrogen ion concentration of both acid and slightly alkaline soils. Sodium salts, including the hydroxide, give lower hydrogenion concentrations than the corresponding potassium or calcium salts, and chlorides give lowerpH values than sulphates. The degree of buffer action (slope of titration curve) is unaffected by the addition of a neutral salt. Previous extraction of a soil with water causes a considerable increase i n thepH value of its suspensions. A number of soils showed a regular increase of about 0·1 inpH. value for twofold dilution. The “salt effect” and “dilution” effect appear to be of the same type. It is recommended that the soil-water ratio of 1:5 be generally adopted. The indicator methyl red gives erroneouspH values in turbid soil suspensions owing to the absorption of the red form, which is apparently a cation capable of undergoing “base exchange” with the soil.

Analysis of water pollution and evaluation of purification measures in an urban river basin

1996 ◽  
Vol 34 (12) ◽  
pp. 33-40 ◽  
Author(s):  
Y. Hosoi ◽  
Y. Kido ◽  
H. Nagira ◽  
H. Yoshida ◽  
Y. Bouda
Keyword(s):  
Water Quality ◽  
River Water ◽  
River Basin ◽  
Urban Areas ◽  
River Flow ◽  
Sea Water ◽  
Water Quality Management ◽  
River Water Quality ◽  
Urban River ◽  
Pollutant Load

The inflow of pollutant load from urban areas and the stagnation of water due to sea water intrusion cause the deterioration of river water quality in tidal zone. In order to improve water quality, various measures such as the reduction of pollutant load by sewage systems, discharge control from sewage treatment plants considering river flow, nutrient removal by aquatic plants, and the dredging of bottom sediments have been examined. The choice of these measures depends on the situation of the river environment and finances. In this study, a field survey was carried out in a typical urban river basin, first. Secondly, on the basis of this survey, a mathematical model was formed to simulate flow and water quality. Several purification alternatives designed for the investigated river basin were comparatively evaluated from the viewpoint of the effect of water quality improvement and their cost. Finally, they were prioritized. Through this case study, a planning process of river water quality management was shown.

Sign in / Sign up

Export Citation Format

Share Document