Role of River–Lake System Sediments and Microbial Activity in the Hyporheic Zone

The effect of river–lake systems on the surface water self-purification process is a significant and not fully recognised scientific issue. The conditions prevailing in the hyporheic zone of these ecosystems are of great importance in the process of component exchange between water and sediments. The aim of this study was to investigate the influence of the type of sediments located at the bottom of the riverbed being part of a river–lake system on microbial activity in the hyporheic zone. An ex situ experiment was used to study the microbiological activity and the transformation of components in the collected river sediments. It was found that the specific properties of sediments varied depending on their location in the riverbed between the lakes comprising the system and that the prevailing meteorological conditions can also have an effect on microbial activity in the hyporheic zone, e.g., aerobic conditions. These conditions determined the intensity of component conversion in the sediments due to microbial metabolism. A closer understanding of the processes occurring in the hyporheic zone may allow the processes of water self-purification within river–lake systems to be supported in the future, which will contribute to the improvement of surface water quality.

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Effects of Fe addition on sediment P dynamics in a eutrophic lake

10.5194/egusphere-egu21-4941 ◽

2021 ◽

Author(s):

Melanie Münch ◽

Rianne van Kaam ◽

Karel As ◽

Stefan Peiffer ◽

Gerard ter Heerdt ◽

...

Keyword(s):

Water Quality ◽

Organic Matter ◽

Surface Water ◽

Water Column ◽

Sediment Cores ◽

Surface Water Quality ◽

Water Interface ◽

Eutrophic Lakes ◽

Fe Addition

The decline of surface water quality due to excess phosphorus (P) input is a global problem of increasing urgency. Finding sustainable measures to restore the surface water quality of eutrophic lakes with respect to P, other than by decreasing P inputs, remains a challenge. The addition of iron (Fe) salts has been shown to be effective in removing dissolved phosphate from the water column of eutrophic lakes. However, the resulting changes in biogeochemical processes in sediments as well as the long-term effects of Fe additions on P dynamics in both sediments and the water column are not well understood.In this study, we assess the impact of past Fe additions on the sediment P biogeochemistry of Lake Terra Nova, a well-mixed shallow peat lake in the Netherlands. The Fe-treatment in 2010 efficiently reduced P release from the sediments to the surface waters for 6 years. Since then, the internal sediment P source in the lake has been increasing again with a growing trend over the years.In 2020, we sampled sediments at three locations in Terra Nova, of which one received two times more Fe during treatment than the other two. Sediment cores from all sites were sectioned under oxygen-free conditions. Both the porewaters and sediments were analysed for their chemical composition, with sequential extractions providing insight into the sediment forms of P and Fe. Additional sediment cores were incubated under oxic and anoxic conditions and the respective fluxes of P and Fe across the sediment water interface were measured.The results suggest that Fe and P dynamics in the lake sediments are strongly coupled. We also find that the P dynamics are sensitive to the amount of Fe supplied, even though enhanced burial of P in the sediment was not detected. The results of the sequential extraction procedure for P, which distinguishes P associated with humic acids and Fe oxides, as well as reduced flux of Fe(II) across the sediment water interface in the anoxic incubations, suggest a major role of organic matter in the interaction of Fe and P in these sediments.Further research will include investigations of the role of organic matter and sulphur in determining the success of Fe-treatment in sequestering P in lake sediments. Based on these data in combination with reactive transport modelling we aim to constrain conditions for successful lake restoration through Fe addition.

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Surface Water Quality and Landscape Gradients in the North Carolina Cape Fear River Basin: The Key Role of Fecal Coliform

Southeastern Geographer ◽

10.1353/sgo.2016.0045 ◽

2016 ◽

Vol 56 (4) ◽

pp. 428-453

Author(s):

Jennifer B. Alford ◽

Keith G. Debbage ◽

Michael A. Mallin ◽

Zhi-Jun Liu

Keyword(s):

Water Quality ◽

North Carolina ◽

Surface Water ◽

River Basin ◽

Fecal Coliform ◽

Surface Water Quality ◽

The North ◽

Landscape Gradients ◽

Cape Fear

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Role of tributaries in Donbas in ensuring the quality of the Siverskyi Donets river surface water

Ukrainian hydrometeorological journal ◽

10.31481/uhmj.24.2019.06 ◽

2019 ◽

pp. 64-71

Author(s):

N. S. Loboda ◽

O. V. Smalii

Keyword(s):

Water Quality ◽

Surface Water ◽

Surface Water Quality ◽

Ecological Condition ◽

Donets Basin ◽

Salt Composition ◽

Ecological Index ◽

Main River

The relevance of the work consists in the need to study the water quality of the Siverskyi Donets River and its tributaries at the beginning of the 21th century, since the river is a main source of water supply in the eastern part of Ukraine. The catchment area of the Siverskyi Donets River is located in the most industrialized region of Ukraine. It is a transboundary river and its catchment is located in the territory of both Ukraine and Russia. The volume of the river's water use, if compared to its runoff volume, is the largest in Ukraine. The condition of water quality is determined by high water consumption and large amount of polluted water being discharged into it. The largest impact is caused by discharges from the residential and commercial complex (big cities) and the enterprises of coal industry, ferrous metallurgy, chemical and petrochemical industry which are concentrated in the Donets Coal Basin. The purpose of this work is to assess the changes of surface water quality of the Siverskyi Donets Basin and to establish the role of the tributaries affected by considerable anthropogenic pressure in the formation of the ecological state of the main river. The research aims at analyzing the hydrochemical indices of the Siverskyi Donets River and its tributaries: the Udy River (9 km to the south from Kharkiv) located in the forest-steppe zone and affected by the wastewater of Kharkiv megalopolis; the Oskil River (Chervonooskilske Reservoir) located in the karst area, having a significant underground water supply and the runoff of which is regulated by the reservoir; the Luhan, Kryvyi Torets, Kazennyi Torets, Bakhmut rivers that are tributaries originating from the Donetsk Highlands and affected by the wastewater of Donbas industrial and municipal enterprises. The subject of the research is the ecological condition of water resources in the rivers of the Siverskyi Donets Basin estimated using the generalized ecological index. The water quality condition was analyzed based on the hydrochemical observations performed from 1990 to 2015 by Central Geophysical Observatory in Kyiv. The main method of research is the method of ecological assessment of surface water quality of land and estuaries in Ukraine using relevant categories. The assessment of the surface water quality using the generalized ecological index (with application of average indicators) showed that the water quality deteriorates along the main river with its worst condition at Lysychansk section. Analysis of the tributaries indicated the worst ecological condition of the Bakhmut River (Donbas). For most of the considered rivers the 3rd class of quality (“satisfactory”), the 4th category ("satisfactory condition and slightly contaminated”) were established. If we consider the index of ecological condition by maximum indicators, the results are almost the same for all the studied rivers: 5th class, 7th category ("very poor condition and very contaminated”). According to the block of salt composition components, the worst ecological condition is established for sections of the Siverskyi Donets River (city of Lysychansk) and the Bakhmut River. The analysis of the generalized ecological index dynamics along the length of the main river indicated a general trend (except for the section in Lysychansk) to water quality improvement. This was achieved following the decrease of toxic effects due to reduction of petroleum products and phenol concentrations. No significant changes in the index were detected for the tributaries. Donbas rivers are also characterized by increase of the salt composition components index: their water is classified as "brackish" whereas the water of other tributaries is classified as “fresh water”. The pollution with nitrogen compounds still remains significant and keeps increasing. The heavy metals content decreases very slowly. The inflow of water of the Donbas rivers to the main river causes significant changes of the ecological condition at the Lysychansk section located downstream from the place of their confluence.

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Spatio-temporal variability of five surface water quality parameters in the Swartvlei estuarine lake system, South Africa

African Journal of Aquatic Science ◽

10.2989/16085914.2015.1029868 ◽

2015 ◽

Vol 40 (2) ◽

pp. 119-131 ◽

Cited By ~ 5

Author(s):

IA Russell

Keyword(s):

South Africa ◽

Water Quality ◽

Surface Water ◽

Temporal Variability ◽

Surface Water Quality ◽

Quality Parameters ◽

Water Quality Parameters ◽

Lake System ◽

Spatio Temporal

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Ground-surface water interactions and the role of the hyporheic zone

Groundwater and Ecosystems ◽

10.1007/1-4020-4738-x_10 ◽

2006 ◽

pp. 131-143 ◽

Cited By ~ 1

Author(s):

Ken W. F. Howard ◽

H. S. Maier ◽

S. L. Mattson

Keyword(s):

Surface Water ◽

Hyporheic Zone ◽

Ground Surface

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A multirate mass transfer model to represent the interaction of multicomponent biogeochemical processes between surface water and hyporheic zones (SWAT-MRMT-R 1.0)

10.5194/gmd-2019-301 ◽

2020 ◽

Author(s):

Yilin Fang ◽

Xingyuan Chen ◽

Jesus Gomez velez ◽

Xuesong Zhang ◽

Zhuoran Duan ◽

...

Keyword(s):

Surface Water ◽

Exchange Rates ◽

Surface Water Quality ◽

Residence Times ◽

Biogeochemical Processes ◽

Channel Water ◽

Hyporheic Zones ◽

Hanford Reach ◽

Multirate Mass Transfer

Abstract. Surface water quality along river corridors can be modulated by hyporheic zones (HZs) that are ubiquitous and biogeochemically active. Watershed management practices often ignore the potentially important role of HZs as a natural reactor. To investigate the effect of hydrological exchange and biogeochemical processes on the fate of nutrients in surface water and HZs, a novel model, SWAT-MRMT-R, was developed coupling the Soil and Water Assessment Tool (SWAT) watershed model and the reaction module from a flow and reactive transport code (PFLOTRAN). SWAT-MRMT-R simulates concurrent nonlinear multicomponent biogeochemical reactions in both the channel water and its surrounding HZs, connecting the channel water and HZs through hyporheic exchanges using multirate mass transfer (MRMT) representation. Within the model, HZs are conceptualized as transient storage zones with distinguished exchange rates and residence times. The biogeochemical processes within HZs are different from those in the channel water. Hyporheic exchanges are modeled as multiple first order mass transfers between the channel water and HZs. As a numerical example, SWAT-MRMT-R is applied to the Hanford Reach of the Columbia River, a large river in the United States, focusing on nitrate dynamics in the channel water. Major nitrate contaminants entering the Hanford Reach include those from the legacy waste, irrigation return flows (irrigation water that is not consumed by crops and runs off as point sources to the stream), and groundwater seepage resulted from irrigated agriculture. A two-step reactions for denitrification and an aerobic respiration reaction are assumed to represent the biogeochemical transformations taking place within the HZs. The spatially variable hyporheic exchange rates and residence times in this example are estimated with the basin-scale Networks with Exchange and Subsurface Storage (NEXSS) model. Our simulation results show that 1) as the commonly used transient storage model for stream–HZ exchange of solutes uses a single residence time to parameterize the exchange coefficient, it may overestimate the nitrate attenuation role of HZs ignoring the contribution from HZs with low residence times; and 2) source locations of nitrate have different impact on surface water quality due to the spatially variable hyporheic exchanges.

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