scholarly journals The metabolic regimes of flowing waters

2017 ◽  
Vol 63 (S1) ◽  
pp. S99-S118 ◽  
Author(s):  
E. S. Bernhardt ◽  
J. B. Heffernan ◽  
N. B. Grimm ◽  
E. H. Stanley ◽  
J. W. Harvey ◽  
...  
Keyword(s):  
Flowing Waters

UV-disinfection of treated wastewater: possible effects on surface waters

1994 ◽  
Vol 29 (12) ◽  
pp. 255-266 ◽  
Author(s):  
T. Gschlößl
Keyword(s):  
Uv Irradiation ◽  
Wastewater Treatment Plants ◽  
Technological Development ◽  
Research Work ◽  
Treatment Plant ◽  
Pilot Project ◽  
Point Sources ◽  
Treated Wastewater ◽  
Bathing Water Directive ◽  
Flowing Waters

UV-irradiation as an effective method of diminishing germs in the outlet of wastewater treatment plants was studied in a half-scale pilot-project sponsored by the State of Bavaria/BRD for a period of 3 years. Technical, physical and biological parameters capable of influencing this process were examined. The possibility to improve the hygienic and also the ecological structure of receiving waters was put to discussion. Possible effects of formed bypproducts upon the water biocoenosis of rivers were pointed out. The results demonstrated that UV-irradiation can diminish the number of germs in the outlet of a treatment plant to an extent which is sufficient to guarantee the maintenance of the bacteriological and presumably also the virological values set by the EC Bathing Water Directive. Nevertheless the UV-treatment process requires further technological development and research work concerning i.e. the improvement of hydraulic conditions, coat-forming on the quartz sleeves of the lamps, photochemical forming of by-products, after-growth and effects upon the localised benthic flora and fauna of the receiving water. It has to be stressed that a significant improvement of the bacteriological structure of flowing waters is only attainable, if the influx from non-point sources can be reduced simultaneously.

scholarly journals Double-diffusive mixing makes a small contribution to the global ocean circulation

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Carine G. van der Boog ◽  
Henk A. Dijkstra ◽  
Julie D. Pietrzak ◽  
Caroline A. Katsman
Keyword(s):  
Ocean Circulation ◽  
Mechanical Energy ◽  
Global Ocean ◽  
Small Contribution ◽  
Global Ocean Circulation ◽  
Diffusive Fluxes ◽  
Diffusive Mixing ◽  
Diffusive Processes ◽  
Flowing Waters ◽  
Double Diffusive

AbstractDouble-diffusive processes enhance diapycnal mixing of heat and salt in the open ocean. However, observationally based evidence of the effects of double-diffusive mixing on the global ocean circulation is lacking. Here we analyze the occurrence of double-diffusive thermohaline staircases in a dataset containing over 480,000 temperature and salinity profiles from Argo floats and Ice-Tethered Profilers. We show that about 14% of all profiles contains thermohaline staircases that appear clustered in specific regions, with one hitherto unknown cluster overlying the westward flowing waters of the Tasman Leakage. We estimate the combined contribution of double-diffusive fluxes in all thermohaline staircases to the global ocean’s mechanical energy budget as 7.5 GW [0.1 GW; 32.8 GW]. This is small compared to the estimated energy required to maintain the observed ocean stratification of roughly 2 TW. Nevertheless, we suggest that the regional effects, for example near Australia, could be pronounced.

scholarly journals Study Concerning the Quality Indices of Flowing Waters. A Case Study: Iara River

2013 ◽  
Vol 70 (2) ◽  
pp. 453-454
Author(s):  
Antonia ODAGIU ◽  
Ioan OROIAN ◽  
Ilie COVRIG ◽  
Tania MIHÄ‚IESCU
Keyword(s):  
Water Pollution ◽  
Water Quality ◽  
Veterinary Medicine ◽  
Public Interest ◽  
Time Interval ◽  
Mountain River ◽  
Quality Indices ◽  
The University ◽  
Flowing Waters

The water pollution is first of all a consequence of the lack of prevention and also inertia of public interest initiatives, often being claimed technical and economical difficulties. The aim of this paper is to present the results of monitoring the water quality from a mountain river. The analysis was carried on within the Laboratory of the Monitoring of Environmental Quality from the Faculty of Agriculture of the University of Agricultural Sciences and Veterinary Medicine Cluj - Napoca, during April - June 2013. Temperature recorded values between 16 -210C pH,  6.5 - 6.9, conductivity 70.2 µS/cm - 72,8 µS/cm, turbidity 0.05 - 0,16 NTU, dissolved oxygen 10.01 -9.10 mg/L. All monitored parameters that are the basis of identification of the water quality indices, during monitored time interval, April 1st - June 26th 2013 framed within normal admitted limits, which demonstrate the lack of pollution of this river segment.

Use of power analysis for determining the number of samples needed to assess water quality in lakes and flowing waters

2021 ◽  
Author(s):  
Andrea L. Conine ◽  
Sarah E. Rickard ◽  
Alene M. Onion ◽  
Eric J. Wiegert ◽  
Alexander J. Smith
Keyword(s):  
Water Quality ◽  
Power Analysis ◽  
Flowing Waters

Riethia (Kieffer 1917) (Diptera: Chironomidae) revised for the Austro-Pacific region

Zootaxa ◽  
2019 ◽  
Vol 4646 (3) ◽  
pp. 461-500 ◽  
Author(s):  
PETER S. CRANSTON
Keyword(s):  
New Zealand ◽  
Adult Male ◽  
New Caledonia ◽  
Molecular Data ◽  
Molecular Evidence ◽  
Pacific Region ◽  
South American Species ◽  
Standing Waters ◽  
Flowing Waters ◽  
Male Pupa

Riethia Kieffer, known previously from New Zealand for a species stated to be also in Australia plus several Australian and South American species, is revised for the Austro-Pacific region. The three previously-described Australian species Riethia stictoptera Kieffer (the genotype), Riethia cinctipes Freeman and Riethia plumosa Freeman are distinct and valid, and are redescribed in all stages. In contrast, Riethia zeylandica Freeman now is restricted to New Zealand: Australian specimens previously allocated to R. zeylandica belong to several new species recognised on morphology of adult male, pupa and larva, with guidance from molecular data. Most belong to a widespread eastern Australian Riethia azeylandica sp. n.: others are allocated to Riethia hamodivisa sp. n., Riethia paluma sp. n., Riethia phengari sp. n. and Riethia queenslandensis sp. n., each with a more restricted range. From Western Australia three species, Riethia donedwardi sp. n., Riethia noongar sp. n. and Riethia wazeylandica sp. n., are described as new from adult male, pupa and larva. Riethia kakadu sp. n. is described from the monsoonal tropics of Northern Territory from the adult male and tentatively associated pupa. From New Caledonia a reared species is described as Riethia neocaledonica sp. n.. Illustrated identification keys are provided for the males, pupae and larvae. Unassociated larvae that key to reared described species are excluded from type status, and based on morphology and molecular evidence three unreared larval types, ‘A’, ‘B’ and ‘C’, are also described and keyed. Previously reported molecular vouchers are reviewed, and certain Genbank accessions re-identified. Extensive data shows Riethia are distributed almost throughout Australia from standing and flowing waters, from tropics and subtropics to cool temperate Tasmania, but probably only in permanent and standing waters. The immature stages of several taxa can co-occur: as many as four can be found simultaneously in one site. Terminology of the volsellae of the male genitalia and the dorsal head and maxilla of the larva is reviewed. 

scholarly journals Near-Wake Flow Structure of a Suspended Cylindrical Canopy Patch

Water ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 84 ◽  
Author(s):  
Ayşe Yüksel Ozan ◽  
Didem Yılmazer
Keyword(s):  
Flow Field ◽  
Flow Structure ◽  
Green Infrastructure ◽  
Nutrient Management ◽  
Wake Flow ◽  
Wake Region ◽  
Near Wake ◽  
Vegetation Patch ◽  
Comprehensive Picture ◽  
Flowing Waters

Urban stormwater is an important environmental problem, especially for metropolitans worldwide. The most important issue behind this problem is the need to find green infrastructure solutions, which provide water treatment and retention. Floating treatment wetlands, which are porous patches that continue down from the free-surface with a gap between the patch and bed, are innovative instruments for nutrient management in lakes, ponds, and slow-flowing waters. Suspended cylindrical vegetation patches in open channels affect the flow dramatically, which causes a deviation from the logarithmic law. This study considered the velocity measurements along the flow depth, at the axis of the patch, and at the near-wake region of the canopy, for different submerged ratios with different patch porosities. The results of this experimental study provide a comprehensive picture of the effects of different submergence ratios and different porosities on the flow field at the near-wake region of the suspended vegetation patch. The flow field was described with velocity and turbulence distributions along the axis of the patch, both upstream and downstream of the vegetation patch. Mainly, it was found that suspended porous canopy patches with a certain range of densities (SVF20 and SVF36 corresponded to a high density of patches in this study) have considerable impacts on the flow structure, and to a lesser extent, individual patch elements also have a crucial role.

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