Characteristics of pore-water chemical composition in bottom sediments of the upper part of the Bratsk reservoir.

Abstract This study was aimed at identifying the processes responsible for the major ion composition of pore water from the bottom sediments of the Bratsk water reservoir, which is a part of the largest freshwater Baikal-Angara water system. The pore water ionic composition varies both along the sediment depth profile and across the water area. In pore water, the difference between the highest and lowest values is remarkably large: 5.1 times for K+, 13 times for Mg2+, 16 times for HCO3-, 20 times for Ca2+, 23 times for Na+, 80 times for SO42-, 105 times for Cl-. Such a variability suggests that the dominant factors, influencing pore water chemistry, depend on the location. At the first stages of the sedimentation process, the chemistry of the pore water in the Bratsk reservoir is dependent on HCO3-Ca of the overlying water. Later on, due to the interaction with the sedimentary terrigenous material, they changed to SO4, SO4-HCO3, HCO3-SO4, HCO3-Cl-SO4-water types with exchangeable cations, mainly Ca. Some of pore waters may have a complex genesis associated with subaqueous groundwater discharge. The change in the redox potential observed in the pore water is the indicator of early-diagenetic transformations taking place in bottom sediments.

Download Full-text

An extended generalized effective stress for active clays

E3S Web of Conferences ◽

10.1051/e3sconf/202019502004 ◽

2020 ◽

Vol 195 ◽

pp. 02004

Author(s):

Angelica Tuttolomondo ◽

Alessio Ferrari ◽

Lyesse Laloui

Keyword(s):

Shear Strength ◽

Chemical Composition ◽

Pore Water ◽

Effective Stress ◽

Environmental Conditions ◽

Chemical Potential ◽

Shear Strength Parameters ◽

Strength Parameters ◽

Saturation State ◽

Water Chemical Composition

An effective stress concept for active clays is formulated to improve the modelling of these materials under a variety of environmental conditions. In particular, the mechanical effects induced by a change in the chemical potential of pore water associated with a change of its pressure (even in the negative range), as well as a change of its chemical composition, are considered. Some implications of the proposed framework are shown with reference to shear strength results related to unsaturated conditions. The proposed approach allows to describe the shear strength envelope consistently by using a unique set of shear strength parameters irrespective of the pore water chemical composition and of the saturation state.

Download Full-text

Hydrochemistry of sediment pore water in the Bratsk reservoir (Baikal region, Russia)

Scientific Reports ◽

10.1038/s41598-021-90603-x ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

V. I. Poletaeva ◽

E. N. Tirskikh ◽

M. V. Pastukhov

Keyword(s):

Pore Water ◽

Ionic Composition ◽

Water System ◽

Water Reservoir ◽

Environmental Parameters ◽

Water Area ◽

Pore Waters ◽

Overlying Water ◽

Major Ion ◽

Bratsk Reservoir

AbstractThis study aimed to identify the factors responsible for the major ion composition of pore water from the bottom sediments of the Bratsk water reservoir, which is part of the largest freshwater Baikal-Angara water system. In the Bratsk reservoir, the overlying water was characterized as HCO3–Ca–Mg type with the mineralization ranging between 101.2 and 127.7 mg L−1 and pore water was characterized as HCO3–SO4–Ca, SO4–Cl–Ca–Mg and mixed water types, which had mineralization varying from 165.9 to 4608.1 mg L−1. The ionic composition of pore waters varied both along the sediment depth profile and across the water area. In pore water, the difference between the highest and lowest values was remarkably large: 5.1 times for K+, 13 times for Mg2+, 16 times for HCO3−, 20 times for Ca2+, 23 times for Na+, 80 times for SO42−, 105 times for Cl−. Such variability at different sites of the reservoir was due to the interrelation between major ion concentrations in the pore water and environmental parameters. The major factor responsible for pore water chemistry was the dissolution of sediment-forming material coming from various geochemical provinces. In the south part of the reservoir, Cl−, Na+ and SO42− concentrations may significantly increase in pore water due to the effect of subaqueous flow of highly mineralized groundwater.

Download Full-text

Sea spray influences water chemical composition of Mediterranean semi-natural springs

CATENA ◽

10.1016/j.catena.2018.10.035 ◽

2019 ◽

Vol 173 ◽

pp. 414-423 ◽

Cited By ~ 2

Author(s):

M. Fernández-Martínez ◽

O. Margalef ◽

F. Sayol ◽

D. Asensio ◽

G. Bagaria ◽

...

Keyword(s):

Chemical Composition ◽

Sea Spray ◽

Water Chemical Composition ◽

Natural Springs

Download Full-text

Effects of Additional Gases Resulting From Residual Water Inside ILW Packages

Volume 7: Operations, Applications and Components ◽

10.1115/pvp2016-63008 ◽

2016 ◽

Author(s):

Marko Nehrig ◽

Frank Wille ◽

Annette Rolle ◽

Konrad Linnemann

Keyword(s):

Chemical Composition ◽

Hydrogen Embrittlement ◽

Thermal Behavior ◽

Pore Water ◽

Safety Assessment ◽

Free Water ◽

Intermediate Level ◽

Residual Water ◽

Gas Generation ◽

Combustible Gases

Packages for intermediate level waste (ILW) often contain residual water besides the actual waste. The water either exists as obvious free water or it may be bound physically or chemically, e.g. as pore water. A water driven gas generation could occur by vaporisation and by radiolysis. Steam as the result of vaporisation causes an increasing pressure inside a package and can affect corrosion. Vaporisation and condensation processes itself change the thermal behavior of the content especially during strongly unsteady thermal situations like accident fire situations. Radiolysis changes the chemical composition of the content which could cause an unexpected interaction, e.g. hydrogen embrittlement. Besides the pressure build-up the radiolysis of water generates hydrogen and oxygen, which can be highly flammable respectively explosive. The gas generation caused by vaporisation and radiolysis must be taken into account during the design and the safety assessment of a package. Pressure build-up, a changed thermal behavior and content chemistry, and especially the risk of accumulation of combustible gases exceeding the limiting concentration for flammability has to be considered in the safety assessment. Approaches to ensure the transportability of stored packages due to radiolysis will be discussed.

Download Full-text