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

2020 ◽  
Author(s):  
Vera Poletaeva ◽  
Elvira Tirskikh ◽  
Mikhail Pastukhov
Keyword(s):  
Pore Water ◽  
Bottom Sediments ◽  
Ionic Composition ◽  
Water System ◽  
Water Reservoir ◽  
Water Area ◽  
Pore Waters ◽  
Overlying Water ◽  
The Difference ◽  
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.

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

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.

scholarly journals Behaviour of Sediments in Water Structures

2020 ◽  
Vol 15 (2) ◽  
pp. 69-74
Author(s):  
Natália Junáková ◽  
Jozef Junák
Keyword(s):  
Bottom Sediments ◽  
Water System ◽  
Water Reservoir ◽  
Sorption Process ◽  
Coarse Grained ◽  
Aqueous Environment ◽  
Technical Problems ◽  
Maximum Sorption Capacity ◽  
Small Water ◽  
High Concentrations

AbstractBottom sediments are a natural part of aquatic ecosystems. They are increasingly contributing to the deterioration of watercourses and reservoirs and are an undesirable material that causes various serious environmental and technical problems. The most significant problems include the instability of riverbeds, the transport of chemicals, nutrients and organic compounds, the supply of sediments to water reservoirs. Bottom sediments have the ability to bind to their surface various predominantly harmful substances such as heavy metals, radionuclides, nutrients and organic substances. Such sediments pose a risk to the water system in terms of possible remobilization of pollutants into the water.This paper is focused on the study of behavior of sediments in the Hervartov small water reservoir located in the east of Slovakia and their ability to adsorb phosphorus at the sediment-water interface. The results show that the efficiency of sorption of phosphorus from the aqueous environment by fine and coarse-grained sediments is the highest at the lowest input concentrations of phosphorus in solution, or at low concentrations in surface water above the sediment. At these concentrations, the amount of sorbed phosphorus by fine-grained sediments was up to almost 99%. The coarse-grained sediments sorbed phosphorus at a level of up to 84%. Increasing the concentration of phosphorus in the solution leads to a decrease in the sorption efficiency of the sediment, while at high concentrations of the sorbate, the sorption process is significantly stabilized due to reaching the maximum sorption capacity of bottom sediments.

Biogeochemical cycling of nutrients and trace metals in anoxic freshwater sediments of the Neckar River, Germany

1995 ◽  
Vol 46 (1) ◽  
pp. 237 ◽  
Author(s):  
Y Song ◽  
G Muller
Keyword(s):  
Organic Matter ◽  
Trace Metals ◽  
Pore Water ◽  
Sediment Cores ◽  
Sharp Decrease ◽  
Metal Sulfides ◽  
Pore Waters ◽  
Overlying Water ◽  
Mineralization Of Organic Matter ◽  
Cycling Of Nutrients

Pore-water components (SO42-, Fe2+, Mn2+), including nutrients (NH4+:, NO3-, PO43-), alkalinity and pH were determined at three sites in the Neckar River. Sequential extraction procedures and trace metals in both pore waters and sediments are reported in order to evaluate the mobility of trace metals in contaminated sediments. The results show that the mineralization of organic matter plays an important role in the cycling of nutrients and trace metals. Pore-water profiles (Zn, Cu, Pb, Cd) suggest that the element maximums at the sediment-water interface are caused by the decomposition of biomass. Low concentrations of dissolved Zn, Cu, Pb and Cd in the anoxic sediments can be explained by a sharp decrease of SO42- in pore water concomitant with HS- production. This leads to the formation of highly insoluble metal sulfides. Solubility calculations show that the sediments act as a sink for trace metals with respect to trace metal sulfides. The organic/sulfidic-bound fraction accounts for 64-81% of Cd in the sediment cores, 36-67% of Pb and 51-69% of Cu. In contrast, Cr in pore water increases with depth because of its release from Fe/Mn oxides. NH4+ and PO43- are also released into the pore water owing to the mineralization of organic matter. No significant fluxes of NH4+ and PO43- into overlying water were found because of the existence of an oxic surface layer.

HEAVY METAL SPECIATION IN BOTTOM SEDIMENTS OF THE VYSHNEVOLOTSKY RESERVOIR

2018 ◽  
pp. 46-54
Author(s):  
O. A. Lipatnikova
Keyword(s):  
Heavy Metal ◽  
Organic Matter ◽  
Bottom Sediments ◽  
Metal Speciation ◽  
Organic Matter Content ◽  
Water Reservoir ◽  
Matter Content ◽  
Heavy Metal Speciation ◽  
Mobile Forms ◽  
Manganese Hydroxides

The study of heavy metal speciation in bottom sediments of the Vyshnevolotsky water reservoir is presented in this paper. Sequential selective procedure was used to determine the heavy metal speciation in bottom sediments and thermodynamic calculation — to determine ones in interstitial water. It has been shown that Mn are mainly presented in exchangeable and carbonate forms; for Fe, Zn, Pb и Co the forms are related to iron and manganese hydroxides is played an important role; and Cu and Ni are mainly associated with organic matter. In interstitial waters the main forms of heavy metal speciation are free ions for Zn, Ni, Co and Cd, carbonate complexes for Pb, fulvate complexes for Cu. Effects of particle size and organic matter content in sediments on distribution of mobile and potentially mobile forms of toxic elements have been revealed.

Influence of pH on the Migration of Various Forms of Metals in the "Bottom Sediments - Water" System under Experimental Conditions

2009 ◽  
Vol 45 (3) ◽  
pp. 92-100 ◽  
Author(s):  
P. N. Linnik ◽  
A. V. Zubko ◽  
I. B. Zubenko ◽  
I. I. Ignatenko ◽  
L. A. Malinovskaya
Keyword(s):  
Bottom Sediments ◽  
Water System ◽  
Experimental Conditions ◽  
Influence Of Ph

Non-steady variations of SOD and phosphate release rate due to changes in the quality of the overlying water

2000 ◽  
Vol 42 (3-4) ◽  
pp. 265-272 ◽  
Author(s):  
T. Inoue ◽  
Y. Nakamura ◽  
Y. Adachi
Keyword(s):  
Release Rate ◽  
Oxygen Demand ◽  
Phosphate Concentration ◽  
Sediment Oxygen Demand ◽  
Biochemical Reactions ◽  
Overlying Water ◽  
Phosphate Release ◽  
Do Concentration ◽  
The Difference

A dynamic model, which predicts non-steady variations in the sediment oxygen demand (SOD) and phosphate release rate, has been designed. This theoretical model consists of three diffusion equations with biochemical reactions for dissolved oxygen (DO), phosphate and ferrous iron. According to this model, step changes in the DO concentration and flow velocity produce drastic changes in the SOD and phosphate release rate within 10 minutes. The vigorous response of the SOD and phosphate release rate is caused by the difference in the time scale of diffusion in the water boundary layer and that of the biochemical reactions in the sediment. Secondly, a negative phosphate transfer from water to sediment can even occur under aerobic conditions. This is caused by the decrease in phosphate concentration in the aerobic layer due to adsorption.

scholarly journals Spatio-temporal Variation in Nutrient Profiles and Exchange Fluxes at the Sediment-Water Interface in Yuqiao Reservoir, China

2019 ◽  
Vol 16 (17) ◽  
pp. 3071 ◽  
Author(s):  
Wen ◽  
Wu ◽  
Yang ◽  
Jiang ◽  
Zhong
Keyword(s):  
Pore Water ◽  
Water Source ◽  
Water Soluble ◽  
Drinking Water Source ◽  
Eutrophic Lakes ◽  
Overlying Water ◽  
Total N ◽  
Yuqiao Reservoir ◽  
Nutrient Profiles ◽  
Main Component

Nutrients released from sediments have a significant influence on the water quality in eutrophic lakes and reservoirs. To clarify the internal nutrient load and provide reference for eutrophication control in Yuqiao Reservoir, a drinking water source reservoir in China, pore water profiles and sediment core incubation experiments were conducted. The nutrients in the water (soluble reactive P (SRP), nitrate-N (NO3−-N), nitrite-N (NO2−-N), and ammonium-N (NH4+-N)) and in the sediments (total N (TN), total P (TP) and total organic carbon (TOC)) were quantified. The results show that NH4+-N was the main component of inorganic N in the pore water. NH4+-N and SRP were higher in the pore water than in the overlying water, and the concentration gradient indicated a diffusion potential from the sediment to the overlying water. The NH4+-N, NO3−-N, and SRP fluxes showed significant differences amongst the seasons. The NH4+-N and SRP fluxes were significantly higher in the summer than in other seasons, while NO3−-N was higher in the autumn. The sediment generally acted as a source of NH4+-N and SRP and as a sink for NO3−-N and NO2−-N. The sediments release 1133.15 and 92.46 tons of N and P, respectively, to the overlying water each year.

Dissolution and recrystallization in modern shelf carbonates: evidence from pore water and solid phase chemistry

1993 ◽  
Vol 344 (1670) ◽  
pp. 27-36 ◽  
Keyword(s):  
Organic Matter ◽  
Pore Water ◽  
Solid Phase ◽  
Chemical Exchange ◽  
Isotope Composition ◽  
Geochemical Data ◽  
Carbonate Sediments ◽  
Pore Waters ◽  
Carbonate Minerals ◽  
Carbonate Production

We present an overview of geochemical data from pore waters and solid phases that clarify earliest diagenetic processes affecting modern, shallow marine carbonate sediments. Acids produced by organic matter decomposition react rapidly with metastable carbonate minerals in pore waters to produce extensive syndepositional dissolution and recrystallization. Stoichiometric relations among pore water solutes suggest that dissolution is related to oxidation of H 2 S which can accumulate in these low-Fe sediments. Sulphide oxidation likely occurs by enhanced diffusion of O 2 mediated by sulphide-oxidizing bacteria which colonize oxic/anoxic interfaces invaginating these intensely bioturbated sediments. Buffering of pore water stable isotopic compositions towards values of bulk sediment and rapid 45 Ca exchange rates during sediment incubations demonstrate that carbonate recrystallization is a significant process. Comparison of average biogenic carbonate production rates with estimated rates of dissolution and recrystallization suggests that over half the gross production is dissolved and/or recrystallized. Thus isotopic and elemental composition of carbonate minerals can experience significant alteration during earliest burial driven by chemical exchange among carbonate minerals and decomposing organic matter. Temporal shifts in palaeo-ocean carbon isotope composition inferred from bulk-rocks may be seriously compromised by facies-dependent differences in dissolution and recrystallization rates.

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