scholarly journals Simulation of pollutants spreading from a sewage outfall in the Rijeka Bay

2020 ◽  
Vol 21 (1) ◽  
pp. 116
Author(s):  
IVA MRŠA HABER ◽  
TARZAN LEGOVIĆ ◽  
LADO KRANJČEVIĆ ◽  
MARIJAN CUKROV
Keyword(s):  
Surface Water ◽  
Cold Water ◽  
Water Layer ◽  
Bottom Layer ◽  
Fecal Coliforms ◽  
Sewage Discharge ◽  
North West ◽  
Sewage Outfall ◽  
Bora Wind ◽  
Mesh Convergence

Results from a 3D numerical simulation of wind-induced currents and pollution spreading from a sewage outfall are described.The goal was to predict seawater sanitary quality in the Rijeka Bay, Adriatic Sea. A sea motion model was coupled with a modelof transport and chemical reactions of fecal coliforms (FC), fecal streptococci (FS) and dissolved oxygen. The selected simulationperiod of 36 hours following wastewater discharge was found to be sufficient for a significant extinction of bacteria. The simulationwas carried out for eight wind directions and two intensities (moderate and high). Mesh convergence was obtained. Twomesh sizes were coupled: coarse, for the whole Bay, and fine, for the northern part of the Bay, close to the sewage discharge ofthe Rijeka city.For all considered wind directions, the pollution plume with a concentration higher than 100 FC and 100 FS per 100 ml of seawateris conveyed mostly parallel to the coast in either north-west or south-east directions. The plume does not rise to the surfacebut stays at the depth of 10 to 20 meters. This is a consequence of the hydrodynamics of the Rijeka Bay: the bora wind carriesthe surface water layer out of the Bay through the Middle and Great Gates, while cold water enters the Bay from the layer belowthe thermocline. During the southern wind (jugo), the situation is reversed: warmer surface water enters the Bay through eitherthe Middle Gate or the Great Gate, while cold seawater exits through the bottom layer, accumulating warmer seawater in the Bay.The conclusion is that the Rijeka city sewage discharge Delta is well-designed, and the microorganism concentration is wellwithin the suggested regulatory range. The discharge site is far enough from the coast, where local streamlines are mostly parallelto the coast, hence the elevated pollution concentration does not come close to swimming and recreational areas. Even if thedischarge increases by 50%, which is unlikely in the near future, the pollution at beaches will stay within regulatory boundaries.

scholarly journals Calcium carbonate saturation in the surface water of the Arctic Ocean: undersaturation in freshwater influenced shelves

2009 ◽  
Vol 6 (11) ◽  
pp. 2421-2431 ◽  
Author(s):  
M. Chierici ◽  
A. Fransson
Keyword(s):  
Calcium Carbonate ◽  
Surface Water ◽  
Cold Water ◽  
Dissolved Inorganic Carbon ◽  
Chukchi Sea ◽  
Total Alkalinity ◽  
The Arctic ◽  
Subsurface Water ◽  
Chukchi Peninsula ◽  
Bering Strait

Abstract. In the summer of 2005, we sampled surface water and measured pH and total alkalinity (AT) underway aboard IB Oden along the Northwest Passage from Cape Farewell (South Greenland) to the Chukchi Sea. We investigated the variability of carbonate system parameters, focusing particularly on carbonate concentration [CO32−] and calcium carbonate saturation states, as related to freshwater addition, biological processes and physical upwelling. Measurements on AT, pH at 15°C, salinity (S) and sea surface temperature (SST), were used to calculate total dissolved inorganic carbon (CT), [CO32−] and the saturation of aragonite (ΩAr) and calcite (ΩCa) in the surface water. The same parameters were measured in the water column of the Bering Strait. Some surface waters in the Canadian Arctic Archipelago (CAA) and on the Mackenzie shelf (MS) were found to be undersaturated with respect to aragonite (ΩAr<1). In these areas, surface water was low in AT and CT (<1500 μmol kg−1) relative to seawater and showed low [CO32−]. The low saturation states were probably due to the likely the effect of dilution due to freshwater addition by sea ice melt (CAA) and river runoff (MS). High AT and CT and low pH, corresponded with the lowest [CO32−], ΩAr and ΩCa, observed near Cape Bathurst and along the South Chukchi Peninsula. This was linked to the physical upwelling of subsurface water with elevated CO2. The highest surface ΩAr and ΩCa of 3.0 and 4.5, respectively, were found on the Chukchi Sea shelf and in the cold water north of Wrangel Island, which is heavily influenced by high CO2 drawdown and lower CT from intense biological production. In the western Bering Strait, the cold and saline Anadyr Current carries water that is enriched in AT and CT from enhanced organic matter remineralization, resulting in the lowest ΩAr (~1.2) of the area.

scholarly journals Heavy Metal Content in Water of Resko Lake (North-West Poland)

2013 ◽  
Vol 13 ◽  
pp. 279-287 ◽  
Author(s):  
Piotr Daniszewski ◽  
Ryszard Konieczny
Keyword(s):  
Surface Water ◽  
Water Samples ◽  
Metal Content ◽  
Research Work ◽  
Average Concentration ◽  
Permissible Limit ◽  
Toxic Heavy Metals ◽  
Annual Average ◽  
North West ◽  
Annual Average Concentration

The present research work deals with the quantification of toxic heavy metals in the water samples collected from Lake of Resko (North-West Poland). While the annual average concentration of Cadmium was calculated as 0.34 ppm in 2008 of the year and 0.28 ppm in 2009 of the year. The values obtained were found to be below the permissible limit of 2.0 ppm set for inland surface water. While the annual average concentration of Chromium was calculated as 1,75 ppm in 2008 of the year and 1.97 ppm in 2009 of the year. Which was very much above the permissible limit of 0.1 ppm set for inland surface water. The observed annual average concentration of Copper in the water was 0.05 ppm in 2008 of the year and 0.06 ppm in 2009 of the year, which was below the permissible limit of 3.0 ppm set for inland surface water. While the annual average concentration of Mercury was calculated as 0.03 ppm in 2008 of the year and 0.04 ppm in 2009 of the year, which was very much above the maximum limit of 0.01 ppm set for inland surface water. The annual average concentration of Nickel in the water samples was observed to be 2.07 ppm in 2008 of the year and 2.09 ppm in 2009 of the year, which is close to the limit of 3.0 ppm set for inland surface water. The annual average concentration of Pb in the water samples was observed to be 0.07 ppm in 2008 of the year and 0.05 ppm in 2009 of the year, which is above the permissible limit of 0.1 ppm set for inland surface water. The results of the present investigation indicate that the annual average concentration of Zn in water samples was 3.02 ppm in 2008 of the year and 2.74 ppm in 2009 of the year, which is above the permissible limit of 5.0 ppm set for inland surface water.

scholarly journals On the possible presence of oxygen in the upper sediment layer of the hydrogen sulfide zone in the Black Sea

2019 ◽  
Vol 59 (1) ◽  
pp. 166-169
Author(s):  
P. A. Stunzhas ◽  
M. B. Gulin ◽  
A. G. Zatsepin ◽  
E. A. Ivanova
Keyword(s):  
Black Sea ◽  
Benthic Fauna ◽  
Water Layer ◽  
Bottom Layer ◽  
The Black Sea ◽  
Depth Range ◽  
Sediment Layer ◽  
Bottom Water Layer ◽  
Long Time ◽  
Eukaryotic Organisms

In the northeastern Black Sea the search was performed for living eukaryotic organisms (micro- and meiobenthos) in hypoxic and anoxic conditions as well as measurement of O2 in the bottom water layer and in the upper layer of sediments. The results have shown the presence of a deep maximum abundance of zoobenthos in a depth range of 215–244 m. This aggregation of benthic fauna occupies a layer of 30 m along the vertical. In general, the proportion of active meiobenthos was no greater than 1.5% of the total number of organisms recorded from the sample.The presence of aerobic benthos near the upper boundary of the H2S zone can be explained by: sliding down of sediments from a higher depth; quasi-periodic O2 supply due to fluctuations in the position of the isopycna and/or sinking of waters downslope in the bottom Ekman layer. Also, in the case of physical entry of oxygen into the bottom layer, it can remain for a relatively long time in the upper part of the H2S zone due to the lack of deep Mn+2 flux and reaction with it.

scholarly journals Draft Genome Sequences of Potentially Pathogenic Clostridium perfringens Strains from Environmental Surface Water in the North West Province of South Africa

2019 ◽  
Vol 8 (32) ◽  
Author(s):  
Johannes Cornelius Jacobus Fourie ◽  
Tomasz J. Sanko ◽  
Cornelius Carlos Bezuidenhout ◽  
Charlotte Mienie ◽  
Rasheed Adegbola Adeleke
Keyword(s):  
South Africa ◽  
Surface Water ◽  
Clostridium Perfringens ◽  
Draft Genome ◽  
Anthropogenic Factors ◽  
Genome Sequences ◽  
Content Type ◽  
North West ◽  
The North ◽  
North West Province

Surface water systems in South Africa are experiencing a major decline in quality due to various anthropogenic factors. This poses a possible health risk for humans. Here, we present the draft genome sequences of three Clostridium perfringens isolates obtained from a fecally polluted river system in the North West province of South Africa.

scholarly journals Hydrochemistry of shallow groundwater and surface water in the Ndop plain, North West Cameroon

2013 ◽  
Vol 7 (6) ◽  
pp. 518-530 ◽  
Author(s):  
J Wirmvem Mengnjo ◽  
Ohba Takeshi ◽  
Y Fantong Wilson ◽  
N Ayonghe Samuel ◽  
Y Suila Justice ◽  
...  
Keyword(s):  
Surface Water ◽  
Shallow Groundwater ◽  
North West

scholarly journals Variability of the Antarctic Slope Current System in the Northwestern Weddell Sea

2017 ◽  
Vol 47 (12) ◽  
pp. 2977-2997 ◽  
Author(s):  
Marina Azaneu ◽  
Karen J. Heywood ◽  
Bastien Y. Queste ◽  
Andrew F. Thompson
Keyword(s):  
Current System ◽  
Water Layer ◽  
Bottom Layer ◽  
Weddell Sea ◽  
The South ◽  
Orkney Islands ◽  
Dense Water ◽  
South Orkney Islands ◽  
Antarctic Slope Current ◽  
The Antarctic

AbstractThe dense water outflow from the Antarctic continental shelf is closely associated with the strength and position of the Antarctic Slope Front. This study explores the short-term and spatial variability of the Antarctic Slope Front system and the mechanisms that regulate cross-slope exchange using highly temporally and spatially resolved measurements from three ocean gliders deployed in 2012. The 22 sections along the eastern Antarctic Peninsula and west of the South Orkney Islands are grouped regionally and composited by isobaths. There is consistency in the front position around the Powell Basin, varying mostly between the 500- and 800-m isobaths. In most of the study area the flow is bottom intensified. The along-slope transport of the Antarctic Slope Current (upper 1000 m) varies between 0.2 and 5.9 Sv (1 Sv ≡ 106 m3 s−1) and does not exhibit a regional pattern. The magnitude of the velocity field shows substantial variability, up to twice its mean value. Higher eddy kinetic energy (0.003 m2 s−2) is observed in sections with dense water, possibly because of baroclinic instabilities in the bottom layer. Distributions of potential vorticity show an increase toward the shelf along isopycnals and also in the dense water layer. Glider sections located west of the South Orkney Islands indicate a northward direction of the flow associated with the Weddell Front, which differs from previous estimates of the mean circulation. This study provides some of the first observational confirmation of the high-frequency variability associated with an active eddy field that has been suggested by recent numerical simulations in this region.

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