scholarly journals Isotope hydrology and water sources in a heavily urbanised stream

2021 ◽  
Author(s):  
Christian Marx ◽  
Doerthe Tetzlaff ◽  
Reinhard Hinkelmann ◽  
Chris Soulsby
Keyword(s):  
Isotopic Composition ◽  
Agricultural Land ◽  
Stream Water ◽  
Treatment Plant ◽  
Temporal Variations ◽  
Water Sources ◽  
Stable Water Isotopes ◽  
Runoff Generation ◽  
Urban Catchments ◽  
Urban Storm

Complex networks of both natural and engineered flow paths control the hydrology of streams in major cities through spatio-temporal variations in connection and disconnection of water sources. We used spatially extensive and temporally intensive sampling of water stable isotopes to disentangle the hydrological sources of the heavily urbanized Panke catchment (≈ 220 km²) in the north of Berlin, Germany. The isotopic data enabled us to partition stream water sources across the catchment using a Bayesian mixing analysis. The upper part of the catchment streamflow here is dominated by groundwater from gravel aquifers underlying surrounding agricultural land. In dry summer periods, streamflow becomes intermittent; possibly as a result of local groundwater abstractions. Urban storm drainage is also an important part of runoff generation, dominating the responses to precipitation events. Although this dramatically changes the isotopic composition of the stream, it only accounts for 10-15% of annual streamflow. Moving downstream, subtle changes in sources and isotope signatures occur as catchment characteristic vary and the stream is affected by different tributary inflows. However, effluent from a wastewater treatment plant (WWTP) serving 700,000 people dominates the stream in the lower catchment where urbanisation effects are more dramatic. The associated increase in sealed surfaces downstream also reduces the relative contribution of groundwater to streamflow. The volume and isotopic composition of storm runoff is again dominated by urban drainage. As a result, only about 10% of annual runoff in the lower catchment comes from urban storm drains. The study shows the potential of stable water isotopes as inexpensive tracers in urban catchments that can provide a more integrated understanding of the complex hydrology of major cities. This offers an important evidence base for guiding the plans to develop and re-develop urban catchments to protect, restore and enhance the ecological and amenity value of these important resources.

scholarly journals Spatio-temporal variations of water sources and mixing spots in a riparian zone

2021 ◽  
Author(s):  
Guilherme E. H. Nogueira ◽  
Christian Schmidt ◽  
Daniel Partington ◽  
Philip Brunner ◽  
Jan H. Fleckenstein
Keyword(s):  
Hot Spots ◽  
Stream Water ◽  
Temporal Variations ◽  
Water Sources ◽  
Fully Integrated ◽  
Complementary Approach ◽  
Spatio Temporal ◽  
High Concentrations ◽  
Dynamic Exchange ◽  
Large Discharge

Abstract. Riparian zones are known to modulate water quality in stream-corridors. They can act as buffers for groundwater borne solutes before they enter the stream at harmful, high concentrations, or facilitate solute turnover and attenuation in zones where stream water (SW) and groundwater (GW) mix. This natural attenuation capacity is strongly controlled by the dynamic exchange of water and solutes between the stream and the adjoining aquifer, creating potential for mixing-dependent reactions to take place. Here, we couple a previously calibrated transient and fully-integrated 3D surface-subsurface, numerical flow model with a Hydraulic Mixing Cell (HMC) method to map the source composition of water along a reach of the 4th-order Selke stream and track its spatio-temporal evolution. This allows us to define zones in the aquifer with similar fractions of surface- and groundwater per aquifer volume (called “mixing hot-spots”), which have a high potential to facilitate mixing-dependent reactions and in turn enhance solute turnover. We further evaluated the HMC results against hydrochemical monitoring data. Our results show that on average about 50 % of the water in the aquifer consists of infiltrating SW. Within about 200 m around the stream the aquifer is almost entirely made up of infiltrated SW with nearly no other water sources mixed in. On average, about 9 % of the aquifer volume could be characterized as “mixing hot-spots”, but this percentage could rise to values nearly 1.5 times higher following large discharge events. Moreover, event intensity (magnitude of peak flow) was found to be more important for the increase of mixing than event duration. Our modelling results further suggest that discharge events more significantly increase mixing potential at greater distances from the stream. In contrast near the stream, the rapid increase of SW influx shifts the ratio between the water fractions to SW, reducing the potential for mixing and the associated reactions. With this easy-to-transfer framework we seek to show the applicability of the HMC method as a complementary approach for the identification of mixing hot-spots in stream corridors, while showing the spatio-temporal controls of the SW-GW mixing process and the implications for riparian biogeochemistry and mixing-dependent turnover processes.

scholarly journals Understanding of Storm Runoff Generation in a Weathered, Fractured Granitoid Headwater Catchment in Northern China

Water ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 123 ◽  
Author(s):  
Sihan Zhao ◽  
Hongchang Hu ◽  
Ciaran Harman ◽  
Fuqiang Tian ◽  
Qiang Tie ◽  
...  
Keyword(s):  
Potential Evapotranspiration ◽  
Stream Water ◽  
Fractured Rock ◽  
Northern China ◽  
Storm Event ◽  
Hydrograph Separation ◽  
Storm Events ◽  
Stable Water Isotopes ◽  
Runoff Generation ◽  
Streamflow Generation

Few of the classical field studies of streamflow generation in headwater watersheds have been conducted in catchments with thin soils and deeply weathered crystalline silicate bedrock. As such, the role of the (potentially very large) storage capacity of weathered, fractured rock in baseflow and storm event discharge remains poorly characterized. Here we present a study of streamflow generation in an upland semi-humid watershed (Xitaizi Experimental Watershed, XEW, 4.22 km2) dominated by baseflow feeding one of the main water supply reservoirs for the city of Beijing, China. This catchment is relatively dry (625 mm/yr precipitation, 480 mm/yr Evapotranspiration), but has strongly seasonal precipitation that varies in phase with strongly seasonal potential evapotranspiration. The catchment was instrumented with four weather stations and precipitation collectors, 11 deep wells drilled into the bedrock along three hillslopes, and additional soil moisture sensors and water samplers along one hillslope. In six storm events over two years, samples of rainfall, soil water (10–80 cm depth), groundwater, and stream water were collected with high frequency and analyzed for stable water isotopes (δ18O and δ2H). Tracer-based hydrograph separation showed that event water (precipitation) makes up the majority of the hydrograph peak above baseflow, and pre-event water contributions (on average) simply represent the steady release of groundwater. The quantity of event water corresponded to a very small effective contributing area (<0.2% of the catchment) that nevertheless showed a clear dependence on catchment wetness as measured by the streamflow. The streamflow itself was isotopically identical to the deep groundwater in wells. This suggests that the fractured, weathered, bedrock system dominates the production of streamflow in this catchment.

Sludge Disposal from an Island Community

1992 ◽  
Vol 25 (12) ◽  
pp. 33-47 ◽  
Author(s):  
T. S. C. Gross ◽  
R. R. Cohen
Keyword(s):  
Agricultural Land ◽  
Waste Heat ◽  
Treatment Plant ◽  
Small Island ◽  
Low Grade ◽  
Sludge Disposal ◽  
Disposal Option ◽  
Total Process ◽  
Island Community ◽  
Farm Produce

The small island of Jersey is served by a single wastewater treatment plant at Bellozanne. Since its inception some 30 years ago the sludge produced has been used on agricultural land. Inevitably there are circumstances which prevent this happening without interruption, eg, poor weather, or seasonal demand. On these occasions, the island has no other disposal option to fall back on. Furthermore, concerns over the practice have created a perception that it might be doing harm to the ‘quality' of the farm produce. The responsible body, the Public Services Department, formulated a flexible, multiple option solution and commissioned Halcrow to engineer the capital works. The works centre around a thermal drying plant using biogas produced by the digestion process as the main fuel. Waste heat is recovered for digester heating making the total process potentially self sufficient in energy. At the same time, the bulk of the product is reduced considerably, providing an easily transported material with potential for use directly on the land as a fertilizer substitute or as a low grade fuel. Farfrom being a disposal problem requiring manpower and expense, sludge will soon be regarded by the States of Jersey as a valuable resource with a revenue potential.

scholarly journals The effect of purified sewage discharge from a sewage treatment plant on the physicochemical state of water in the receiver

2016 ◽  
Vol 48 (3) ◽  
pp. 267-284
Author(s):  
Włodzimierz Kanownik ◽  
Agnieszka Policht-Latawiec ◽  
Magdalena Wiśnios
Keyword(s):  
Water Saturation ◽  
Stream Water ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Fold Increase ◽  
Municipal Sewage ◽  
Stream Water Quality ◽  
Sewage Discharge ◽  
Physicochemical State

Abstract The paper presents changes in the contents of physicochemical indices of the Sudół stream water caused by a discharge of purified municipal sewage from a small mechanical-biological treatment plant with throughput of 300 m3·d−1 and a population equivalent (p.e.) – 1,250 people. The discharge of purified sewage caused a worsening of the stream water quality. Most of the studied indices values increased in water below the treatment plant. Almost a 100-fold increase in ammonium nitrogen, 17-fold increase in phosphate concentrations and 12-fold raise in BOD5 concentrations were registered. Due to high values of these indices, the water physicochemical state was below good. Statistical analysis revealed a considerable effect of the purified sewage discharge on the stream water physicochemical state. A statistically significant increase in 10 indices values (BOD5, COD-Mn, EC, TDS, Cl−, Na+, K+, PO43−, N-NH4+ and N-NO2) as well as significant decline in the degree of water saturation with oxygen were noted below the sewage treatment plant. On the other hand, no statistically significant differences between the water indices values were registered between the measurement points localised 150 and 1,000 m below the purified sewage discharge. It evidences a slow process of the stream water self-purification caused by an excessive loading with pollutants originating from the purified sewage discharge.

Runoff generation processes in permafrost-influenced area of the Heihe River Headwater

2021 ◽  
Author(s):  
Fan Zhang ◽  
Xiong Xiao ◽  
Guanxing Wang
Keyword(s):  
Soil Water ◽  
Stream Water ◽  
Hydrological Regime ◽  
Summer Rainfall ◽  
Frozen Soil ◽  
Heihe River ◽  
The Tibetan Plateau ◽  
Permafrost Degradation ◽  
Runoff Generation ◽  
Spring Snowmelt

&lt;p&gt;Permafrost degradation under global warming may change the hydrological regime of the headwater catchments in alpine area such as the Tibetan Plateau (TP). In this study, he runoff generation processes in permafrost-influenced area of the Heihe River Headwater were investigated with the following results: 1) The observed stable isotope values of various water types on average was roughly in the order of snowfall and snowmelt &lt; bulk soil water (BSW) &lt; rainfall , stream water, mobile soil water (MSW) , and lateral subsurface flow. The depleted spring snowmelt and enriched summer rainfall formed tightly bound soil water and MSW, respectively. The dynamic mixing between tightly bound soil water and MSW resuted in BSW with more depleted and variable stable isotopic feature than MSW. 2) Along with the thawing of the frozen soil, surface runoff and shallowsubsurface flow (SSF) at 30&amp;#8722;60 cm was the major flow pathway in the permafrost influenced alpine meadow hillslope during spring snowmelt and summer rainfall period, reapectively, with the frozen soil maintaining supra-permafrost water level. 3) Comparison between two neighouring catchments under similar precipitation conditions indicated that streamflow of the lower catchment with less permafrost proportion and earlier thawing time has larger SSF and higher based flow component, indicating the potential changes of hydrological regims subject to future warming.&lt;/p&gt;

Hydrogeochemical temporal variations related to changes of seismic activity at Tenerife, Canary Islands

2021 ◽  
Author(s):  
Cecilia Amonte ◽  
María Asensio-Ramos ◽  
Gladys V. Melián ◽  
Nemesio M. Pérez ◽  
Eleazar Padrón ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Seismic Activity ◽  
Temporal Variations ◽  
Total Alkalinity ◽  
Molar Ratio ◽  
Sampling Point ◽  
Volcanic System ◽  
Mean Values ◽  
Isotopic Analyses ◽  
San Fernando

&lt;p&gt;The oceanic active volcanic island of Tenerife (2034 km&lt;sup&gt;2&lt;/sup&gt;) is the largest of the Canarian archipelago. There are more than 1,000 galleries (horizontal drillings) in the island, which are used for groundwater exploitation and allow reaching the aquifer at different depths and elevations. During a two-year period (July 2016 to July 2018), a hydrogeochemical study was carried out in two galleries on Tenerife (Fuente del Valle and San Fernando) for volcanic monitoring purposes with weekly sampling. Physicochemical parameter of water, such us temperature (&amp;#186;C), pH and electrical conductivity (E.C., &amp;#181;S&amp;#183;cm&lt;sup&gt;-1&lt;/sup&gt;), were measured in-situ at each sampling point and chemical/isotopic composition of the water determined later in the laboratory.&lt;/p&gt;&lt;p&gt;Temperature values showed mean values of 28.1 &amp;#186;C and 19.0 &amp;#186;C for Fuente del Valle and San Fernando galleries, respectively. According to the average pH values, which were 6.30 for Fuente del Valle and 7.13 for San Fernando, and based on the chemical composition, both galleries are sodium-bicarbonate (Na-HCO&lt;sub&gt;3&lt;/sub&gt;) type. E.C. values in both galleries presented high ranges, with mean values of 975 and 1648 &amp;#181;S&amp;#183;cm&lt;sup&gt;-1&lt;/sup&gt; for Fuente del Valle and San Fernando, respectively. The total alkalinity mean value of groundwater from Fuente del Valle gallery was 11.3 mEq&amp;#183;L&lt;sup&gt;-1&lt;/sup&gt; HCO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;, while that from San Fernando was 17.3 mEq&amp;#183;L&lt;sup&gt;-1&lt;/sup&gt; HCO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;. The SO&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2-&lt;/sup&gt;/Cl molar ratio was 0.59 and 3.4 for the samples from Fuente del Valle and San Fernando galleries, respectively.&lt;/p&gt;&lt;p&gt;The &amp;#948;&lt;sup&gt;18&lt;/sup&gt;O and &amp;#948;D isotopic analyses showed a meteoric origin of groundwaters, with mean values of -6.2&amp;#8240; and -26&amp;#8240; vs. VSMOW for Fuente del Valle and -6.2&amp;#8240; and -21 &amp;#8240; vs. VSMOW for San Fernando. The isotopic data showed a strong interaction with endogenous gases such as CO&lt;sub&gt;2&lt;/sub&gt;, H&lt;sub&gt;2&lt;/sub&gt;S, H&lt;sub&gt;2&lt;/sub&gt;, etc. Regarding the isotopic composition of total dissolved carbon species, expressed as &amp;#948;&lt;sup&gt;13&lt;/sup&gt;C&lt;sub&gt;TDIC&lt;/sub&gt;, average values of -0.17&amp;#8240; and 0.26&amp;#8240; were obtained for Fuente del Valle and San Fernando galleries, respectively. These results show an endogenous origin CO&lt;sub&gt;2&lt;/sub&gt; signature, heavier for Fuente del Valle gallery groundwater compared to that of San Fernando.&lt;/p&gt;&lt;p&gt;Groundwater physicochemical parameters exhibited stable values throughout the study period, while significant temporal variations were observed in the total alkalinity, SO&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2-&lt;/sup&gt;/Cl&lt;sup&gt;-&lt;/sup&gt; molar ratio, &amp;#948;&lt;sup&gt;18&lt;/sup&gt;O and &amp;#948;D. Changes in isotopic ratios coincided with variations observed in the alkalinity and the SO&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2-&lt;/sup&gt;/Cl&lt;sup&gt;-&lt;/sup&gt; molar ratio. On October 2, 2016, a seismic swarm of long-period events was recorded on Tenerife followed by a general increase of the seismic activity in and around the island. A correlation was observed between some hydrogeochemical parameters in the groundwaters of the galleries, related to observed changes of the seismic activity. This study demonstrates the suitability of monitoring the chemical and isotopic composition of groundwater from Fuente del Valle and San Fernando galleries, as they are sensitive to changes in volcanic activity on Tenerife island. The study of groundwaters associated to a volcanic system can provide information about the magmatic gas input in the aquifer, modelling how the groundwaters flow through the edifice, and offer important geochemical information that could herald a future eruption.&lt;/p&gt;

Effects of phosphorus recovery requirements on Swedish sludge management

2002 ◽  
Vol 46 (4-5) ◽  
pp. 435-440 ◽  
Author(s):  
E. Levlin ◽  
M. Löwén ◽  
K. Stark ◽  
B. Hultman
Keyword(s):  
Phosphorus Removal ◽  
Agricultural Land ◽  
Treatment Plant ◽  
Phosphorus Recovery ◽  
Molar Ratio ◽  
Toxic Substances ◽  
Biological Phosphorus Removal ◽  
Sludge Management ◽  
Small Stream ◽  
Sludge Disposal

Expected requirements of phosphorus recovery, restrictions on sludge disposal on landfill, and difficulties in obtaining consensus on sludge use on agricultural land has led to several development works in Sweden to change sludge management methods. Especially sludge fractionation has gained interest including following steps to recover products and separate transfer of toxic substances into a small stream. Commercial systems are offered based on technology by Cambi/KREPRO and BioCon and other companies and many other methods are under development. Iron salts are widely used in Sweden as precipitation agents for phosphorus removal and this technology has some disadvantages for phosphorus recovery compared with the use of biological phosphorus removal. The amount of chemicals needed for a KREPRO or a BioCon system was calculated for a treatment plant which has an addition of iron salt resulting in 1,900 mole Fe per tonne DS. The result was compared with the chemical consumption of recovery systems installed at plants with lower use of iron for precipitation. The chemical consumption in equivalents per tonne DS was found to be 5,000 + 6,000 * (molar ratio iron to phosphorus).

scholarly journals An Optimized Snowmelt Lysimeter System for Monitoring Melt Rates and Collecting Samples for Stable Water Isotope Analysis

2019 ◽  
Vol 67 (1) ◽  
pp. 20-31 ◽  
Author(s):  
Andrea Rücker ◽  
Massimiliano Zappa ◽  
Stefan Boss ◽  
Jana von Freyberg
Keyword(s):  
Isotopic Composition ◽  
Isotope Analysis ◽  
Ground Level ◽  
Isotopic Signature ◽  
Small Scale ◽  
Spatial And Temporal Variability ◽  
Environmental Tracers ◽  
Hydrograph Separation ◽  
Stable Water Isotopes ◽  
Restricted Volume

Abstract The contribution of snow meltwater to catchment streamflow can be quantified through hydrograph separation analyses for which stable water isotopes (18O, 2H) are used as environmental tracers. For this, the spatial and temporal variability of the isotopic composition of meltwater needs to be captured by the sampling method. This study compares an optimized snowmelt lysimeter system and an unheated precipitation collector with focus on their ability to capture snowmelt rates and the isotopic composition of snowmelt. The snowmelt lysimeter system consists of three individual unenclosed lysimeters at ground level with a surface of 0.14 m2 each. The unheated precipitation collector consists of a 30 cm-long, extended funnel with its orifice at 2.3 m above ground. Daily snowmelt samples were collected with both systems during two snowfall-snowmelt periods in 2016. The snowmelt lysimeter system provided more accurate measurements of natural melt rates and allowed for capturing the small-scale variability of snowmelt process at the plot scale, such as lateral meltwater flow from the surrounding snowpack. Because of the restricted volume of the extended funnel, daily melt rates from the unheated precipitation collector were up to 43% smaller compared to the snowmelt lysimeter system. Overall, both snowmelt collection methods captured the general temporal evolution of the isotopic signature in snowmelt.

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