Characteristics of stable isotope and hydrochemistry of surface water, and their significance on the Huaibei plain, China

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.

Download Full-text

Distribution, Sources and Water Quality Evaluation of the Riverine Solutes: A Case Study in the Lancangjiang River Basin, Tibetan Plateau

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph16234670 ◽

2019 ◽

Vol 16 (23) ◽

pp. 4670 ◽

Cited By ~ 3

Author(s):

Jinke Liu ◽

Guilin Han ◽

Man Liu ◽

Jie Zeng ◽

Bin Liang ◽

...

Keyword(s):

Water Quality ◽

Chemical Composition ◽

River Water ◽

Major Ions ◽

Pearson Correlation ◽

Silicate Weathering ◽

Carbonate Weathering ◽

Atmospheric Input ◽

River Waters ◽

Anthropogenic Inputs

To examine the chemical composition, potential sources of solutes, and water quality of Lancangjiang River, the concentrations of major ions (Ca2+, Mg2+, Na+, K+, HCO3−, SO42−, Cl− and NO3−) in 45 river water samples collected in July and August 2019 were determined. Ca2+ and HCO3− are the predominant ions in river water. The extremely low K+ and NO3− concentrations and the sparse population suggest that the anthropogenic inputs are limited. The Pearson correlation coefficients and the elemental ratios Ca2+/Na+ versus Mg2+/Na+, Ca2+/Na versus HCO3−/Na+, [Ca2+ + Mg2+]/[HCO3−] versus [SO42−]/[HCO3−] reveal the mixing processes of different sources; the chemical composition of the river water is controlled by the mixture of carbonate weathering, evaporite weathering and silicate weathering inputs. To quantify the contributions of atmospheric input and rock dissolution, the forward method is employed in this study, which is based on the mass balance equation. The calculation results suggest the carbonate weathering inputs and gypsum dissolution make up the majority of the riverine cations, while silicate weathering and halite dissolution constitutes a relatively small proportion, the contributions of the atmospheric input are limited. The fast dissolution rate of evaporite and carbonate minerals and their lithologic distributions should be the key factor. To evaluate the water quality for drinking and irrigation purposes, the drinking water quality guidelines and the calculated parameters were employed, including sodium adsorption ratio (SAR), soluble sodium percentage (Na%,) and residual sodium carbonate (RSC). The assessments indicate that the river waters in the middle-lower reaches are generally suitable for irrigation and drinking purpose, and will not lead to health and soil problems, such as soil compaction and salinization. While in the upper reaches, the dissolution of carbonate and gypsum minerals transport abundant ions into river water and the river waters are not appropriate to use directly. This result highlights that the water quality status can also be affected by natural weathering processes in the area without anthropogenic inputs, where the long-time monitoring of water quality is also necessary.

Download Full-text

Bacterially Assisted Oxidation of Copper Sulfide Minerals in Tropical River Waters

Environmental Chemistry ◽

10.1071/en04064 ◽

2005 ◽

Vol 2 (1) ◽

pp. 49 ◽

Cited By ~ 10

Author(s):

Stuart L. Simpson ◽

Simon C. Apte ◽

Cheryl M. Davies

Keyword(s):

River Water ◽

Water Samples ◽

Copper Sulfide ◽

Sulfide Minerals ◽

Tropical River ◽

River Waters ◽

Oxidation Rates ◽

River Water Samples ◽

Copper Release ◽

Particulate Copper

Environmental Context. It is well known that bacteria can significantly accelerate oxidation rates of copper sulfide minerals under acidic conditions. However, this process is not thought to be important at higher pH. This study reports the bacterially assisted oxidation of copper sulfide minerals in slightly alkaline (pH 8.0–8.3) tropical river waters downstream of a large copper mine. This process leads to significant solubilization of copper from particulate phases. Abstract. Field and laboratory experiments are reported which demonstrate the bacterially facilitated oxidation of copper sulfide minerals in the water column of tropical rivers. When river water samples, collected downstream of a large copper mine, were incubated under controlled laboratory conditions (pH 8.0–8.3) significant dissolved copper release was observed. This was accompanied by an increase in cold acid soluble particulate copper, indicating oxidation of copper sulfides. Dissolved copper release and copper sulfide oxidation were markedly lower in sterile control samples demonstrating biological mediation. In samples collected close to the mine discharge, dissolved copper release ceased after the first 150 h of incubation, presumably following the consumption of easily oxidizable solid copper sulfide phases or armouring of particles with insoluble oxidation products. Attempts to isolate the bacteria responsible were unsuccessful. However, oxidation rates could be enhanced by culturing aliquots of unfiltered river water samples in simple mineral media (pH 7.0) amended only with sulfide. This provided strong evidence that the copper sulfide oxidizing bacteria were chemolithotrophs. Our results suggest that such bacteria are naturally present in mineralized areas and are actively involved in the cycling of particulate copper between sulfide and hydroxy-carbonate forms, thus influencing the solubility and bioavailability of copper.

Download Full-text