scholarly journals Understanding groundwater, surface water, and hyporheic zone biogeochemical processes in a Chalk catchment using fluorescence properties of dissolved and colloidal organic matter

2009 ◽  
Vol 114 ◽  
Author(s):  
D. J. Lapworth ◽  
D. C. Gooddy ◽  
D. Allen ◽  
G. H. Old
Keyword(s):  
Organic Matter ◽  
Surface Water ◽  
Hyporheic Zone ◽  
Fluorescence Properties ◽  
Biogeochemical Processes

scholarly journals Nitrogen Retention in Headwater Streams: The Influence of Groundwater-Surface Water Exchange

2001 ◽  
Vol 1 ◽  
pp. 623-631 ◽  
Author(s):  
S.A. Thomas ◽  
H.M. Valett ◽  
P.J.. Mulholland ◽  
C.S. Fellows ◽  
J.R. Webster ◽  
...  
Keyword(s):  
Surface Water ◽  
Water Exchange ◽  
Hyporheic Zone ◽  
Headwater Streams ◽  
Important Determinant ◽  
Nitrogen Retention ◽  
Biologically Active ◽  
Biogeochemical Processes ◽  
N Dynamics ◽  
Research Questions

Groundwater-surface water (GW-SW) interaction lengthens hydraulic residence times, increases contact between solutes and biologically active surfaces, and often creates a gradient of redox conditions conducive to an array of biogeochemical processes. As such, the interaction of hydraulic patterns and biogeochemical activity is suspected to be an important determinant of elemental spiraling in streams. Hydrologic interactions may be particularly important in headwater streams, where the extent of the GW-SW mixing environment (i.e., hyporheic zone) is proportionately greater than in larger streams. From our current understanding of stream ecosystem function, we discuss nitrogen (N) spiraling, present a conceptual model of N retention in streams, and use both of these issues to generate specific research questions and testable hypotheses regarding N dynamics in streams.

scholarly journals Nitrogen attenuation, dilution and recycling in the intertidal hyporheic zone of a subtropical estuary

2018 ◽  
Vol 22 (7) ◽  
pp. 4083-4096 ◽  
Author(s):  
Sébastien Lamontagne ◽  
Frédéric Cosme ◽  
Andrew Minard ◽  
Andrew Holloway
Keyword(s):  
Surface Water ◽  
Hyporheic Zone ◽  
Isotopic Fractionation ◽  
Hyporheic Exchange ◽  
Biogeochemical Processes ◽  
Intertidal Sediments ◽  
Intertidal Zones ◽  
N Removal ◽  
Subtropical Estuary ◽  
Biogeochemical Transformations

Abstract. Tidal estuarine channels have complex and dynamic interfaces controlled by upland groundwater discharge, waves, tides and channel velocities that also control biogeochemical processes within adjacent sediments. In an Australian subtropical estuary, discharging groundwater with elevated (> 300 mg N L−1) NH4+ and NO3- concentrations had 80 % of the N attenuated at this interface, one of the highest N removal rates (> 100 mmol m−2 day−1) measured for intertidal sediments. The remaining N was also diluted by a factor of 2 or more by mixing with surface water before being discharged to the estuary. Most of the mixing occurred in a hyporheic zone in the upper 50 cm of the channel bed. However, groundwater entering this zone was already partially mixed (12 %–60 %) with surface water via tide-induced circulation. Below the hyporheic zone (50–125 cm below the channel bed), NO3- concentrations declined slightly faster than NH4+ concentrations and δ15NNO3 and δ18ONO3 gradually increased, suggesting a co-occurrence of anammox and denitrification. In the hyporheic zone, δ15NNO3 continued to become enriched (consistent with either denitrification or anammox) but δ18ONO3 became more depleted (indicating some nitrification). A high δ15NNO3 (23 ‰–35 ‰) and a low δ18ONO3 (1.2 ‰–8.2 ‰) in all porewater samples indicated that the original synthetic nitrate pool (industrial NH4NO3; δ15N ∼ 0 ‰; δ18O ∼ 18 ‰–20 ‰) had turned over completely during transport in the aquifer before reaching the channel bed. Whilst porewater NO3- was more δ18O depleted than its synthetic source, porewater δ18OH2O (−3.2 ‰ to −1.8 ‰) was enriched by 1 ‰–4 ‰ relative to rainfall-derived groundwater mixed with seawater. Isotopic fractionation from H2O uptake during the N cycle and H2O production during synthetic NO3- reduction are the probable causes for this δ18OH2O enrichment. Whilst occurring at a smaller spatial scale than tide-induced circulation, hyporheic exchange can provide a similar magnitude of mixing and biogeochemical transformations for groundwater solutes discharging through intertidal zones.

Simultaneous fate of trace organic compounds and dissolved organic matter in surface water and the hyporheic zone of an urban river

2020 ◽  
Author(s):  
Birgit Maria Mueller ◽  
Hanna Schulz ◽  
Anke Putschew ◽  
Jörg Lewandowski
Keyword(s):  
Organic Matter ◽  
Surface Water ◽  
Dissolved Organic Matter ◽  
Organic Compounds ◽  
Water Samples ◽  
Hyporheic Zone ◽  
Treated Wastewater ◽  
Turnover Rates ◽  
Trace Organic Compounds ◽  
Trace Organic

<p>Rivers being influenced by treated wastewater are characterized by an altered water chemistry compared to their natural state. Downstream of the outlet of a wastewater treatment plant (WWTP), concentrations of dissolved organic matter (DOM) and trace organic compounds (TrOCs) in the receiving river are increased. As DOM might serve as a metabolic co-substrate during microbial TrOC degradation, DOM influences the attenuation of TrOCs. Due to steep biochemical gradients at the surface water - groundwater interface, the hyporheic zone is considered a hotspot for microbial activity. Therefore, turnover rates in the hyporheic zone of a stream are high in comparison to the turnover rates in the water column. The River Erpe is a sandy lowland river in the East of Berlin, Germany, which receives treated wastewater from the WWTP Muenchehofe. In order to study the simultaneous fate of TrOCs and DOM in surface water and the hyporheic zone, a field sampling campaign was conducted at a side channel of the River Erpe. Surface water samples were taken at site A and both surface and pore water samples from 25 cm sediment depth were taken at site B which is 850 m downstream of site A. The sampling interval was every three hours over 48 hours. Samples were analysed for 17 TrOCs (HPLC-MS/MS) and the molecular composition of DOM (FT-ICR MS). DOM compound classes were calculated semi-quantitatively as the percentage share of each class of the whole DOM composition. Mean concentrations of the TrOCs analysed changed by an increase of 200 % to a decrease of 29 % in the surface water between site A and B and by a decrease of 5 to 93 % in the hyporheic zone at site B. The molecular composition of DOM changed at most by a single digit percentage per compound group with the attenuation being larger in the hyporheic zone. The percentage share of two out of seven DOM compound classes significantly correlated with the concentration of at least ten TrOCs between surface water at site A and B. Such a correlation was observed for five compound classes in the hyporheic zone at site B. The present study shows that the attenuation of both TrOCs and DOM in a sandy urban river mainly takes place in the hyporheic zone but it is not capable of assuming a causal relationship between the attenuation of TrOCs and DOM.</p>

scholarly journals Simultaneous attenuation of trace organics and change in organic matter composition in the hyporheic zone of urban streams

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Birgit M. Mueller ◽  
Hanna Schulz ◽  
Robert E. Danczak ◽  
Anke Putschew ◽  
Joerg Lewandowski
Keyword(s):  
Organic Matter ◽  
Surface Water ◽  
Molecular Diversity ◽  
Hyporheic Zone ◽  
Transformation Product ◽  
Treated Wastewater ◽  
Hyporheic Exchange ◽  
Urban Stream ◽  
Strong Correlations ◽  
High Attenuation

AbstractTrace organic compounds (TrOCs) enter rivers with discharge of treated wastewater. These effluents can contain high loads of dissolved organic matter (DOM). In a 48 h field study, we investigated changes in molecular composition of seven DOM compound classes (FTICR-MS) and attenuation of 17 polar TrOCs in a small urban stream receiving treated wastewater. Correlations between TrOCs and DOM were used to identify simultaneous changes in surface water and the hyporheic zone. Changes in TrOC concentrations in surface water ranged between a decrease of 29.2% for methylbenzotriazole and an increase of 152.2% for the transformation product gabapentin-lactam. In the hyporheic zone, only decreasing TrOC concentrations were observed, ranging from 4.9% for primidone to 93.8% for venlafaxine . TrOC attenuation coincided with a decline of molecular diversity of easily biodegradable DOM compound classes while molecular diversity of poorly biodegradable DOM compound classes increased. This concurrence indicates similar or linked attenuation pathways for biodegradable DOM and TrOCs. Strong correlations between TrOCs and DOM compound classes as well as high attenuation of TrOCs primarily occurred in the hyporheic zone. This suggests high potential for DOM turnover and TrOC mitigation in rivers if hyporheic exchange is sufficient.

scholarly journals Effect of Digestate and Straw Combined Application on Maintaining Rice Production and Paddy Environment

2021 ◽  
Vol 18 (11) ◽  
pp. 5714
Author(s):  
Xue Hu ◽  
Hongyi Liu ◽  
Chengyu Xu ◽  
Xiaomin Huang ◽  
Min Jiang ◽  
...  
Keyword(s):  
Organic Matter ◽  
Surface Water ◽  
Soil Organic Matter ◽  
Paddy Soil ◽  
Rice Yield ◽  
Soil Surface ◽  
Rice Production ◽  
Straw Decomposition ◽  
Rice Grains ◽  
Combined Application

Few studies have focused on the combined application of digestate and straw and its feasibility in rice production. Therefore, we conducted a two-year field experiment, including six treatments: without nutrients and straw (Control), digestate (D), digestate + fertilizer (DF), digestate + straw (DS), digestate + fertilizer + straw (DFS) and conventional fertilizer + straw (CS), to clarify the responses of rice growth and paddy soil nutrients to different straw and fertilizer combinations. Our results showed that digestate and straw combined application (i.e., treatment DFS) increased rice yield by 2.71 t ha−1 compared with the Control, and digestate combined with straw addition could distribute more nitrogen (N) to rice grains. Our results also showed that the straw decomposition rate at 0 cm depth under DS was 5% to 102% higher than that under CS. Activities of catalase, urease, sucrase and phosphatase at maturity under DS were all higher than that under both Control and CS. In addition, soil organic matter (SOM) and total nitrogen (TN) under DS and DFS were 20~26% and 11~12% higher than that under B and DF respectively, suggesting straw addition could benefit paddy soil quality. Moreover, coupling straw and digestate would contribute to decrease the N content in soil surface water. Overall, our results demonstrated that digestate and straw combined application could maintain rice production and have potential positive paddy environmental effects.

Removal of the Neutral Dissolved Organic Matter (NDOM) from Surface Water by Coagulation/Flocculation and Nanofiltration

2021 ◽  
pp. 1-14
Author(s):  
Sami Khettaf ◽  
Roumaissa Boumaraf ◽  
Fatiha Benmahdi ◽  
Kamel-Eddine Bouhidel ◽  
Mohammed Bouhelassa
Keyword(s):  
Organic Matter ◽  
Surface Water ◽  
Dissolved Organic Matter

Upgrading of waterworks with a new biooxidation process for removal of manganese and iron

1998 ◽  
Vol 37 (9) ◽  
pp. 121-126 ◽  
Author(s):  
T. Hedberg ◽  
T. A. Wahlberg
Keyword(s):  
Organic Matter ◽  
Water Treatment ◽  
Surface Water ◽  
Pilot Plant ◽  
Previous Treatment ◽  
Full Scale ◽  
Unit Operations ◽  
Treatment Water

The paper describes how waterworks can be upgraded by the use of microbiologically unit operations to make it possible to remove manganese from groundwater and surface water. Pilot plant studies and full-scale plant studies show that conventional oxidants as permanganate may be replaced by biooxidation thus reducing the use of chemicals in water treatment. Water containing high amounts of Fe and/or Mn and organic matter may be difficult to treat and pilot plant studies are therefore recommended. This study shows that one ground waterworks and one surface waterworks succed in removing manganese where previous treatment with permangante had failed.

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