Dynamic boundary conditions control the spatial and temporal variations of nutrient turnover in human impacted surface waters

2020 ◽  
Author(s):  
Tobias Schuetz ◽  
Anna Kurm ◽  
Till Gößges ◽  
Marion Groß ◽  
Selina Schmitz ◽  
...  
Keyword(s):  
Boundary Conditions ◽  
Temporal Dynamics ◽  
Treatment Plant ◽  
Temporal Variations ◽  
Pharmaceutical Products ◽  
Water Levels ◽  
Hyporheic Exchange ◽  
Biomass Growth ◽  
Nutrient Cycles ◽  
Ambient Conditions

<p>The temporal dynamics of nutrient cycles and the remineralization of micropollutants in given stream or river sections are driven by a complex interplay of hydraulic, climatic and ecological processes which are difficult to quantify and to predict. Typically, we use either e.g. water levels or velocity, radiation input, oxygen availability, water and air temperatures, hyporheic exchange or the activity of auto- and heterotroph organisms alone or in combination to explain observed rates of substance cycling. To improve the predictability of occurring nutrient cycles and biomass growth we selected seven river reaches (1.5 -3.3 km) throughout the Mosel-region in western Germany which are located down stream of sewage water treatment plant effluents. Over a time span of four months we carried out about 10 longitudinal snapshot sampling campaigns at each of the river sections. We sampled for nutrients (C, N, P) and selected pharmaceutical products as well as the hydraulic and climatic and boundary conditions. Additionally, at one of the river sites we observed along the river reach weekly microbial biofilm growth rates, microbial biodiversity (DNA), macrozoobenthos biodiversity in the dominating streambed substrates as well as weekly samples of C, N, P in the sediment.</p><p>The results show clearly how the interplay between hydraulic and climatic boundary conditions controls ongoing nutrient cycles and process rates; e. g. the spatial (downstream) extent of measurable surplus C, N, and P varies clearly over time as well as between the substances (P > C > N). Restricted by hydraulic boundary conditions, biomass production and a reduced (function specific) biodiversity of microbial biofilms coincide either with high nutrient surplus or with exposition to solar radiation. Favorable ambient conditions (lower water levels and higher energy availabilty) are dominant drivers for observable removal of pharmaceutical products rather than nutrient availability. Overall, our results demonstrate the importance of the local settings (cross section, shading) in combination with season and hydraulic loadings at given river sections for occurring process rates in nutrient cycles and biomass growth.</p>

Seasonal variations in surface water groundwater interaction alter the relation of solute transport and biogeochemical processes in the hyporheic zone

2021 ◽  
Author(s):  
Lara-Maria Schmitgen ◽  
Tobias Schuetz
Keyword(s):  
Surface Water ◽  
Boundary Conditions ◽  
Hyporheic Zone ◽  
Treatment Plant ◽  
Hyporheic Exchange ◽  
Waste Water Treatment Plant ◽  
Small Scale ◽  
Vertical Profiles ◽  
Surface Water And Groundwater ◽  
Exchange Flux

<p>The hyporheic interstitial as interface between surface water and groundwater offers a unique environment for contaminant attenuation and nutrient cycling, with steep chemical gradients and high retention times. Disentangling the effect of seasonal dynamics in exchange flux intensities and directions, we carried out 19 measurement campaigns where we sampled the continuum surface water - hyporheic zone - groundwater and the climatic and hydraulic boundary conditions of a whole year. Groundwater, surface water and hyporheic zone pore water from four depths were sampled at two vertical profiles in a second order stream about 150 m downstream a municipal waste water treatment plant effluent. Samples were analyzed for physical water parameters, major anions, ammonium, iron, manganese, NPOC and five selected pharmaceuticals (diclofenac, carbamazepine, caffeine, ethinylestradiol and clofibric acid). Surface water and groundwater levels as well as river discharge were measured to quantify the hydraulic boundary conditions. In addition, three vertical profiles, each equipped with five newly developed probes (Truebner AG) allowed a parallel monitoring of continuous bulk water temperatures and bulk electrical conductivity dynamics over two years. Furthermore, continuous hyporheic exchange flux intensities and exchange depths were calculated using analytical and numerical model schemes to allow distinguishing between small scale transport and attenuation processes.</p><p>The typical behavior of the redox sensitive metals and nutrients with depth is visible in each single profile snapshot. The picture is not as clear for the examined pharmaceuticals, because dilution has a major effect on the observable low concentrations. However, a clear seasonal variation driven by hydraulic and climatic processes can be observed for all substances. We were able to trace the organic pollutants down to the groundwater. Furthermore, the influence of hyporheic exchange flux intensities and directions on nutrient and contaminant depth profiles is shown.</p>

scholarly journals Dampak Dosis Kompos Kotoran Sapi Terhadap Profil Suhu Tanah di Zona Perakaran dan Produktivitas Tanaman Pakcoy (Brassica rafa L)

2019 ◽  
Vol 7 (2) ◽  
pp. 253
Author(s):  
I Made Andi Purnama Wijaya ◽  
Yohanes Setiyo ◽  
I Wayan Tika
Keyword(s):  
Physical Properties ◽  
Root Zone ◽  
Treatment Plant ◽  
Dry Weight ◽  
Fertilizer Application ◽  
Water Levels ◽  
Optimum Dose ◽  
Root Zone Temperature ◽  
Rooting Zone ◽  
Treatment Dose

Suhu tanah adalah salah satu sifat fisik tanah yang secara langsung mempengaruhi pertumbuhan tanaman pakcoy. Tujuan penelitian ini adalah (1) untuk menganalisis suhu di zona perakaran, (2) menganalisis hubungan antara dosis pemupukan mempergunakan kompos dengan suhu di zona perakaran dan (3) untuk menganalis suhu yang optimum untuk produktivitas dan kualitas pakcoy yang dihasilkan saat panen. Rancangan penelitian yang digunakan rancangan acak lengkap, dengan lima perlakuan dan tiga ulangan. Perlakuan tersebut adalah P0 : dosis kompos 0 kg/m2, P1 : dosis kompos 1 kg/m2, P2 : dosis kompos 2 kg/m2, P3 : dosis kompos 3 kg/m2, dan P4 : dosis kompos 4 kg/m2. Parameter yang diamati pada penelitian ini adalah suhu udara, suhulingkungan, kadar air tanah dan produktivitas. Padamalam hari suhu tanah di zona perakaran lebih tinggi 0,59 oC dari pada suhu lingkungan. Suhu tanah di zona perakaran terendah dan tertinggi adalah 18,02 oC dan 21,94 oC. Suhu tanah malam hari dan siang hari untuk dosis 0-5kg/m2 masih toleran pada tanaman pacoy. Berat kering tanaman pakcoy tertinggi pada perlakuan dosis kompos 4kg/m2 denganberat 92,21 gram/tanaman dan terendah pada perlakuan kontrol dengan berat 71,82 gram/tanaman.   The temperature of the soil is one of the physical properties of the soil, this soil physical properties direc2tly affect plant growth pakcoy.  The purpose of this research are (1) to analyze the temperature at root zone, temperature inside and out of the mini greenhouse, (2) analyze the relationship between temperature at root zone  with doses of compost fertilizer application and 3) to analyze the optimum dose of compost based on productivity and quality of the pakcoy is generated when the harvest. The design of the research used randomized complete design, with five treatments and three replicates. The treatment is P0: a dose of compost 0 kg/m, P1: a dose of compost 1 kg/m2, P2: a dose of compost 2 kg/m2, P3: the dose of compost 3 kg/m2, and P4: a dose of compost 4 kg/m2. The parameters observed in this research is the air temperature, the temperature of the environment, ground water levels and productivity.  At night the temperature of the soil rooting zone higher at 0.59 ºC than at the temperature of the environment. Soil temperature at root zone the lowest  and the highest  are 18.02 oC and 21.94 oC.  The temperature of the soil the night and during the day for dose 0-5 kg/m2 was still tolerant plants pakcoy. Dry weight of the plant the highest pakcoy on the treatment dose of compost 4 kg/m2  with a weight of 92.21 grams/lowest at the treatment plant and the control by the weight of 71.82 grams/plant.

scholarly journals Spatial and Temporal Variations of Nitrogen and Phosphorus in Surface Water and Groundwater of Mudong River Watershed in Huixian Karst Wetland, Southwest China

2021 ◽  
Vol 13 (19) ◽  
pp. 10740
Author(s):  
Linyan Pan ◽  
Junfeng Dai ◽  
Zhiqiang Wu ◽  
Liangliang Huang ◽  
Zupeng Wan ◽  
...  
Keyword(s):  
Surface Water ◽  
Temporal Dynamics ◽  
Flow Direction ◽  
Influencing Factor ◽  
Shallow Groundwater ◽  
Temporal Variations ◽  
Field Investigation ◽  
Spatial And Temporal Variation ◽  
Nitrogen And Phosphorus ◽  
River Watershed

When considering the factors affecting the spatial and temporal variation of nitrogen and phosphorus in karst watersheds, the unique karst hydrogeology as an internal influencing factor cannot be ignored, as well as natural factors such as meteorological hydrology and external factors such as human activities. A watershed-scale field investigation was completed to statistically analyze spatial and temporal dynamics of nitrogen and phosphorus through the regular monitoring and collection of surface water and shallow groundwater in the agricultural-dominated Mudong River watershed in the Huixian Karst Wetland over one year (May 2020 to April 2021). Our research found that non-point source pollution of nitrogen (84.5% of 239 samples TN > 1.0 mg/L) was more serious than phosphorus (7.5% of 239 samples TP > 0.2 mg/L) in the study area, and shallow groundwater nitrogen pollution (98.3% of 118 samples TN > 1.0 mg/L) was more serious than surface water (68.6% of 121 samples TN > 1.0 mg/L). In the three regions with different hydrodynamic features, the TN concentration was higher and dominated by NO3−-N in the river in the northern recharge area, while the concentrations of TN and TP were the highest in shallow groundwater wells in the central wetland core area and increased along the surface water flow direction in the western discharge area. This research will help improve the knowledge about the influence of karst hydrodynamic features on the spatial patterns of nitrogen and phosphorus in water, paying attention to the quality protection and security of water in karst areas with a fragile water ecological environment.

scholarly journals Hyporheic exchange controlled by dynamic hydrologic boundary conditions

2016 ◽  
Vol 43 (9) ◽  
pp. 4408-4417 ◽  
Author(s):  
Noah M. Schmadel ◽  
Adam S. Ward ◽  
Christopher S. Lowry ◽  
Jonathan M. Malzone
Keyword(s):  
Boundary Conditions ◽  
Hyporheic Exchange

scholarly journals Spatio-Temporal Dynamics of Riverine Nitrogen and Phosphorus at Different Catchment Scales in Huixian Karst Wetland, Southwest China

Water ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2924
Author(s):  
Linyan Pan ◽  
Junfeng Dai ◽  
Zhiqiang Wu ◽  
Zupeng Wan ◽  
Zhenyu Zhang ◽  
...  
Keyword(s):  
Human Activities ◽  
Temporal Dynamics ◽  
Temporal Variations ◽  
Spatial And Temporal Variations ◽  
Catchment Scale ◽  
Nitrogen And Phosphorus ◽  
Spatial And Temporal Scales ◽  
River Waters ◽  
Hydrological Conditions ◽  
Spatio Temporal

Spatio-temporal dynamics of riverine nitrogen (N) and phosphorus (P) in karst regions are closely linked to hydrological conditions, human activities and karst features in upstream catchments. From October 2017 to September 2019, we undertook 22 sampling campaigns in 11 nested catchments ranging from 21.00 to 373.37 km2 in Huixian karst wetland to quantify forms, concentrations, and fluxes of riverine total nitrogen (TN) and total phosphorus (TP), and to identify spatial and temporal variations of nutrients transfer from upstream to downstream, tributaries (Mudong River and Huixian River) to the main stem (Xiangsi River) in the dry and wet seasons. Considering the hydrological conditions, human activities and karst features within upstream catchments, the following three spatial and temporal variations of riverine nutrients were found over the monitoring period: (1) the dynamics of riverine nitrogen and phosphorus varied seasonally with hydrological conditions; (2) the spatial disparities of riverine nitrogen and phosphorus were induced by different human activities within catchment scales; (3) the dynamics of riverine nitrogen and phosphorus varied similarly at spatial scale restricted by karst features. The findings from this study may improve our understanding of the influence of hydrological conditions, human activities and karst features on nitrogen and phosphorus variations in river waters at different spatial and temporal scales in the Huixian karst wetland basin, and will help managers to protect and restore river water environments in karst basin from a catchment-scale perspective.

scholarly journals Passive Solar Photocatalytic Treatment of Emerging Contaminants in Water: A Field Study

Catalysts ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1045 ◽  
Author(s):  
Gisoo Heydari ◽  
Cooper H. Langford ◽  
Gopal Achari
Keyword(s):  
Solar Energy ◽  
Organic Contaminants ◽  
Emerging Contaminants ◽  
Naphthenic Acid ◽  
Temporal Variations ◽  
Ambient Conditions ◽  
Glass Spheres ◽  
Northern Latitudes ◽  
Slow Kinetics ◽  
Dichlorophenoxy Acetic Acid

Global economic shifts towards utilization of solar energy provides opportunities for photocatalytic technologies that can harness this abundant source of energy for treatment of organic contaminants. The majority of studies in this area have been performed under artificial light, whereas in this paper, the efficacy of passive photocatalysis was studied under sunlight. Buoyant titanium dioxide (TiO2) coated glass spheres were used to treat 2, 4-dichlorophenoxy acetic acid (2, 4-D), methyl chlorophenoxy propionic acid (MCPP), and 3, 6-Dichloro-2-methoxy benzoic acid (Dicamba) in Killex®, a commercially available herbicide. Furthermore, photocatalytic degradation of sulfolane and a typical naphthenic acid (cyclopentane carboxylic acid—CPA) were also tested under ambient conditions. The results showed 99.8% degradation of 2, 4-D, 100% degradation of both MCPP and Dicamba in Killex® solution, and 97.4% degradation of sulfolane by capturing 3.18 MJ/m2 solar energy. Total organic carbon (TOC) was decreased by 88% and 64% in both solutions, respectively. TOC of the aqueous solution containing 20 ppm CPA was also decreased by 78.4% with 7.8 MJ/m2 energy. Despite the slow kinetics and the temporal variations of sunlight in northern latitudes, the results indicated that passive photocatalysis is a promising approach for treatment of contaminants under ambient conditions.

Using data mining to explore the spatial and temporal dynamics of perceptions of metro services in China: The case of Shenzhen

2020 ◽  
pp. 239980832097469
Author(s):  
Shuli Luo ◽  
Sylvia Y He
Keyword(s):  
Social Media ◽  
Temporal Dynamics ◽  
Waiting Times ◽  
Temporal Variations ◽  
Transport Systems ◽  
Transport Services ◽  
Service Areas ◽  
Metro Systems ◽  
Using Data ◽  
Use Of Social Media

Improving perceptions of service quality is a promising planning strategy for increasing the attractiveness and retaining the ridership of public transport systems. The widespread use of social media presents an opportunity to investigate the performance of transport services from the customer’s perspective. This study proposes a framework for integrating quantitative and qualitative analyses to investigate the perceptions of transport services by mining data from social media. We utilise Sina Weibo data related to the Shenzhen metro system to illustrate a text mining process categorised by semantic, spatial and temporal information. On the semantic front, in addition to identifying service attributes and sentiment polarity consistent with previous literature, we find attributes specific to the Chinese context. We also identify clear temporal variations among different service attributes by visualising the number of corresponding microblogs across varying time scales such as hours, days and weekdays. The spatial variations reveal five main clusters around central business districts and transport hubs, which produce the highest density of reports about crowdedness, waiting times, reliability and frequency. However, microblogs that report on perceptions of safety and personnel behaviour present a different spatial pattern. This research offers insights into the ways in which we can use social media data to identify key service areas for immediate improvement and to monitor and manage metro systems more effectively over the long term.

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