Application of the flow-through analyses of ammonia and calcium in ice core and fresh water by fluorometric detection

2001 ◽  
Vol 5 (1-2) ◽  
pp. 29-36 ◽  
Author(s):  
Masahiro Maruo ◽  
Eiichiro Nakayama ◽  
Hajime Obata ◽  
Kokichi Kamiyama ◽  
Takashi Kimoto
Keyword(s):  
Fresh Water ◽  
Ice Core ◽  
Fluorometric Detection ◽  
Flow Through

scholarly journals Short Term Effects of Salinization on Compound Release from Drained and Restored Coastal Wetlands

Water ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1549 ◽  
Author(s):  
Haojie Liu ◽  
Bernd Lennartz
Keyword(s):  
Fresh Water ◽  
Coastal Wetlands ◽  
Saline Water ◽  
Breakthrough Curves ◽  
Water Salinity ◽  
Retardation Factor ◽  
Peat Soils ◽  
Exchange Processes ◽  
Nacl Concentration ◽  
Flow Through

Over the past two decades, great efforts have been made to restore coastal wetlands through the removal of dikes, but challenges remain because the effects of flooding with saline water on water quality are unknown. We collected soil samples from two adjacent coastal fen peatlands, one drained and diked, the other open to the sea and rewetted, aiming at assessing the mobility and export of various compounds. Microcosm experiments with constant flow-through conditions were conducted to determine the effluent concentrations of dissolved organic carbon (DOC), ammonium ( NH 4 + ), and phosphate ( PO 4 3 − ) during saline–fresh water cycles. Sodium chloride (NaCl) was used to adjust salinity (saline water, NaCl concentration of 0.12 mol L−1; fresh water, NaCl concentration of 0.008 mol L−1) and served as a tracer. A model analysis of the obtained chloride ( Cl − ) and sodium ( Na + ) breakthrough curves indicated that peat soils have a dual porosity structure. Sodium was retarded in peat soils with a retardation factor of 1.4 ± 0.2 due to adsorption. The leaching tests revealed that water salinity has a large impact on DOC, NH 4 + , and PO 4 3 − release. The concentrations of DOC in the effluent decreased with increasing water salinity because the combination of high ionic strength (NaCl concentration of 0.12 mol L−1) and low pH (3.5 to 4.5) caused a solubility reduction. On the contrary, saline water enhanced NH 4 + release through cation exchange processes. The PO 4 3 − concentrations, however, decreased in the effluent with increasing water salinity. Overall, the decommissioning of dikes at coastal wetlands and the flooding of once drained and agriculturally used sites increase the risk that especially nitrogen may be leached at higher rates to the sea.

scholarly journals Stratigraphy, stable isotopes and salinity in multi-year sea ice from the rift area, south George VI Ice Shelf, Antarctic Peninsula

1991 ◽  
Vol 37 (127) ◽  
pp. 357-367
Author(s):  
J.-L. Tison ◽  
E. M. Morris ◽  
R. Souchez ◽  
J. Jouzel
Keyword(s):  
Stable Isotopes ◽  
Sea Ice ◽  
Fresh Water ◽  
Large Scale ◽  
Sea Water ◽  
Ice Core ◽  
Ice Shelf ◽  
The Core ◽  
Brackish Ice ◽  
Ice Production

AbstractResults from a detailed profile in a 5.54 m multi-year sea-ice core from the rift area in the southern part of George VI Ice Shelf are presented. Stratigraphy, stable isotopes and Na content are used to investigate the growth processes of the ice cover and to relate them to melting processes at the bottom of the ice shelf.The thickest multi-year sea ice in the sampling area appears to be second-year sea ice that has survived one melt season. Combined salinity/stable-isotope analyses show large-scale sympathetic fluctuations that can be related to the origin of the parent water. Winter accretion represents half of the core length and mainly consists of frazil ice of normal sea-water origin. However, five major dilution events of sea water, with fresh-water input from the melting base of the ice shelf reaching 20% on two occasions, punctuate this winter accretion. Two of them correspond to platelet-ice production, which is often related to the freezing of ascending supercooled water from the bottom of the ice shelf.Brackish ice occurs between 450 and 530 cm in the core. It is demonstrated that this results from the freezing of brackish water (Jeffries and others, 1989) formed by mixing of normal sea water with melted basal shelf ice, with dilution percentages of maximum 80% fresh water.

scholarly journals Stratigraphy, stable isotopes and salinity in multi-year sea ice from the rift area, south George VI Ice Shelf, Antarctic Peninsula

1991 ◽  
Vol 37 (127) ◽  
pp. 357-367 ◽  
Author(s):  
J.-L. Tison ◽  
E. M. Morris ◽  
R. Souchez ◽  
J. Jouzel
Keyword(s):  
Stable Isotopes ◽  
Sea Ice ◽  
Fresh Water ◽  
Large Scale ◽  
Sea Water ◽  
Ice Core ◽  
Ice Shelf ◽  
The Core ◽  
Brackish Ice ◽  
Ice Production

AbstractResults from a detailed profile in a 5.54 m multi-year sea-ice core from the rift area in the southern part of George VI Ice Shelf are presented. Stratigraphy, stable isotopes and Na content are used to investigate the growth processes of the ice cover and to relate them to melting processes at the bottom of the ice shelf.The thickest multi-year sea ice in the sampling area appears to be second-year sea ice that has survived one melt season. Combined salinity/stable-isotope analyses show large-scale sympathetic fluctuations that can be related to the origin of the parent water. Winter accretion represents half of the core length and mainly consists of frazil ice of normal sea-water origin. However, five major dilution events of sea water, with fresh-water input from the melting base of the ice shelf reaching 20% on two occasions, punctuate this winter accretion. Two of them correspond to platelet-ice production, which is often related to the freezing of ascending supercooled water from the bottom of the ice shelf.Brackish ice occurs between 450 and 530 cm in the core. It is demonstrated that this results from the freezing of brackish water (Jeffries and others, 1989) formed by mixing of normal sea water with melted basal shelf ice, with dilution percentages of maximum 80% fresh water.

scholarly journals How much Arctic fresh water participates in the subpolar overturning circulation?

2021 ◽  
Author(s):  
Isabela Le Bras ◽  
Fiamma Straneo ◽  
Morven Muilwijk ◽  
Lars Henrik Smedsrud ◽  
Feili Li ◽  
...  
Keyword(s):  
Fresh Water ◽  
Climate Models ◽  
Deep Ocean ◽  
The Arctic ◽  
Water Fluxes ◽  
Overturning Circulation ◽  
Ice Melt ◽  
Flow Through ◽  
Heat Budgets ◽  
Water Outflow

<p><span>Fresh Arctic waters flowing into the Atlantic are thought to have two primary fates. They may be mixed into the deep ocean as part of the overturning circulation, or flow alongside regions of deep water formation without impacting overturning. Climate models suggest that as increasing amounts of fresh water enter the Atlantic, the overturning circulation will be disrupted, yet we lack an understanding of how much fresh water is mixed into the overturning circulation's deep limb in the present day. To constrain these fresh water pathways, we build steady-state volume, salt, and heat budgets east of Greenland that are initialized with observations and closed using inverse methods. Fresh water sources are split into oceanic Polar Waters from the Arctic and surface fresh water fluxes, which include net precipitation, runoff, and ice melt, to examine how they imprint the circulation differently. We find that 65 mSv of the total 110 mSv of surface fresh water fluxes that enter our domain participate in the overturning circulation, as do 0.6 Sv of the total 1.2 Sv of Polar Waters that flow through Fram Strait. Based on these results, we hypothesize that the overturning circulation is more sensitive to future changes in Arctic fresh water outflow and precipitation, while Greenland runoff and iceberg melt are more likely to stay along the coast of Greenland.</span></p>

scholarly journals Water Circulation and Ice Accretion Beneath Ward Hunt Ice Shelf (Northern Ellesmere Island, Canada), Deduced From Salinity and Isotope Analysis of Ice Cores

1988 ◽  
Vol 10 ◽  
pp. 68-72 ◽  
Author(s):  
Martin O. Jeffries ◽  
William M. Sackinger ◽  
H. Roy Krouse ◽  
Harold V. Serson
Keyword(s):  
Sea Ice ◽  
Fresh Water ◽  
Sea Water ◽  
Ice Core ◽  
Isotope Analysis ◽  
Ice Cores ◽  
Water Circulation ◽  
Ice Shelf ◽  
The West ◽  
Water Ice

Ice-core drilling and ice-core analysis (electrical conductivity–salinity, 18O, 3H, density) reveal that the internal structure of the west Ward Hunt Ice Shelf contrasts sharply with that of the east ice shelf. The west ice shelf contains a great thickness (≥22 m) of sea ice (mean salinity, 2.22‰; mean δ18O, -0.8‰), whereas the east ice shelf is entirely of meteoric or fresh-water ice (mean salinity 0.01‰; mean δ18O, -29.7‰). High tritium activities are found only in ice from near the bottom of the east and west ice shelves. The contrasting ice-core data is considered to be a proxy record of variations in water circulation and bottom freezing beneath the ice shelf. The west shelf is underlain by sea water flowing into Disraeli Fiord. Sea ice accretes on to the bottom of the west ice shelf from the sea-water flowing into the fiord. Sea-water flowing out of the fiord is directed below the east ice shelf. However, the east ice shelf is not underlain directly by sea-water but by a layer of fresh water from the surface of Disraeli Fiord. In this region, ice growth resulting from the presence of this stable fresh-water layer has been accompanied by surface ablation over a period of perhaps the last 450 years. As a result, fresh-water ice has completely replaced any sea ice that originally grew in the region of the east ice shelf. Whereas the west and east shelves are underlain almost exclusively by sea-water and fresh water, ice in the south shelf is the result of freezing of fresh, brackish or sea water. This is attributed to mixing of the inflowing and outflowing waters.

scholarly journals Status-quo of the different canal systems of Punjab, India

2021 ◽  
Vol 889 (1) ◽  
pp. 012063
Author(s):  
Harinderpal Singh Bedi ◽  
Sandeep Singh
Keyword(s):  
Fresh Water ◽  
Water Distribution ◽  
Status Quo ◽  
The State ◽  
Agricultural Products ◽  
Present Condition ◽  
The Status ◽  
Canal Systems ◽  
Flow Through ◽  
Three Rivers

Abstract In India, Punjab is a state which grows large proportion of countries agricultural products and the dependence of cultivatable land, for irrigation, is highly shifting towards the use of surface water. Currently, there are three major fresh water rivers that flow through Punjab i.e., Ravi, Beas and Satluj. Since, India’s independence and its partition, several reforms have taken place with respect to the modifications in the flow of these rivers. As several activities of the state such as, industrial, domestic, geo-political etc., are dependent on the availability of the fresh water, therefore, it is imperative to provide the status-quo of the changes in the rivers of Punjab. This article brings forward, the present condition of the three rivers of Punjab with respect to the development of canals, construction of headworks, dams etc. It is expected that this article will provide an insight of the complete fresh water distribution in the state Punjab, India, to the various stakeholders of associated fields.

scholarly journals Water Circulation and Ice Accretion Beneath Ward Hunt Ice Shelf (Northern Ellesmere Island, Canada), Deduced From Salinity and Isotope Analysis of Ice Cores

1988 ◽  
Vol 10 ◽  
pp. 68-72 ◽  
Author(s):  
Martin O. Jeffries ◽  
William M. Sackinger ◽  
H. Roy Krouse ◽  
Harold V. Serson
Keyword(s):  
Sea Ice ◽  
Fresh Water ◽  
Sea Water ◽  
Ice Core ◽  
Isotope Analysis ◽  
Ice Cores ◽  
Water Circulation ◽  
Ice Shelf ◽  
The West ◽  
Water Ice

Ice-core drilling and ice-core analysis (electrical conductivity–salinity, 18O, 3H, density) reveal that the internal structure of the west Ward Hunt Ice Shelf contrasts sharply with that of the east ice shelf. The west ice shelf contains a great thickness (≥22 m) of sea ice (mean salinity, 2.22‰; mean δ18O, -0.8‰), whereas the east ice shelf is entirely of meteoric or fresh-water ice (mean salinity 0.01‰; mean δ18O, -29.7‰). High tritium activities are found only in ice from near the bottom of the east and west ice shelves. The contrasting ice-core data is considered to be a proxy record of variations in water circulation and bottom freezing beneath the ice shelf. The west shelf is underlain by sea water flowing into Disraeli Fiord. Sea ice accretes on to the bottom of the west ice shelf from the sea-water flowing into the fiord. Sea-water flowing out of the fiord is directed below the east ice shelf. However, the east ice shelf is not underlain directly by sea-water but by a layer of fresh water from the surface of Disraeli Fiord. In this region, ice growth resulting from the presence of this stable fresh-water layer has been accompanied by surface ablation over a period of perhaps the last 450 years. As a result, fresh-water ice has completely replaced any sea ice that originally grew in the region of the east ice shelf. Whereas the west and east shelves are underlain almost exclusively by sea-water and fresh water, ice in the south shelf is the result of freezing of fresh, brackish or sea water. This is attributed to mixing of the inflowing and outflowing waters.

Studies on the Design of Reverse Osmosis Water Desalination Systems for Cost and Energy Efficiency

2010 ◽  
Author(s):  
Karim Hamza ◽  
Mohammed Shalaby ◽  
Ashraf O. Nassef ◽  
Mohamed F. Aly ◽  
Kazuhiro Saitou
Keyword(s):  
Optimal Design ◽  
Reverse Osmosis ◽  
Fresh Water ◽  
Unit Cost ◽  
Minimum Cost ◽  
Water Desalination ◽  
Salt Ions ◽  
Cost Of Energy ◽  
Flow Through ◽  
The Cost

This paper explores optimal design of reverse osmosis (RO) systems for water desalination. In these systems, salty water flows at high pressure through vessels containing semi-permeable membrane modules. The membranes can allow water to flow through, but prohibit the passage of salt ions. When the pressure is sufficiently high, water molecules will flow through the membranes leaving the salt ions behind, and are collected in a fresh water stream. Typical system design variables include the number and layout of the vessels and membrane modules, as well as the operating pressure and flow rate. This paper presents models for single and two-stage pressure vessel configurations. The models are used to explore the various design scenarios in order to minimize the cost and energy required per unit volume of produced fresh water. Multi-objective genetic algorithm (GA) is used to generate the Pareto-optimal design scenarios for the systems. Case studies are considered for four different water salinity concentration levels. Results of the studies indicate that even though the energy required to drive the RO system is a major contributor to the cost of fresh water production, there exists a tradeoff between minimum energy and minimum cost. An additional parametric study on the unit cost of energy is performed in order to explore future trends. The parametric study demonstrates how an increase in the unit cost of energy may shift the minimum cost designs to shift to more energy-efficient design scenarios.

Determination of propranolol in plasma by radial compression liquid chromatography with fluorometric detection.

1985 ◽  
Vol 31 (7) ◽  
pp. 1196-1197 ◽  
Author(s):  
A el-Yazigi ◽  
C R Martin
Keyword(s):  
Internal Standard ◽  
Fluorometric Detection ◽  
Radial Compression ◽  
Monobasic Sodium Phosphate ◽  
Routine Monitoring ◽  
Micron Particle ◽  
One Step ◽  
Flow Through ◽  
Liquid Chromatographic

Abstract This radial compression liquid-chromatographic assay for propranolol in plasma is rapid, reproducible, and suitable for use in routine monitoring. A 10-micron particle, 8 mm X 10 cm CN cartridge is used in conjunction with a radial compression separation system. The mobile phase is monobasic sodium phosphate (pH 3) solution/methanol/acetonitrile (760/84/156 by vol), the flow rate 6 mL/min. Propranolol was detected by use of a spectrofluorometer equipped with a 20-microL flow-through cell, at excitation and emission wavelengths of 250 and 336 nm. The retention times for propranolol and metoprolol (the internal standard) are 3.13 and 1.42 min, respectively. A one-step extraction with chloroform yields "clean" chromatograms, with greater than 90% of the drug being analytically accounted for. Under these conditions, results are precise and accurate. Currently we are using this method to monitor propranolol in hypertensive neonates. Data on changes in the concentrations of propranolol in plasma with time are presented for one such patient.

The Effects of Chronic Cyanide Poisoning on the Tolerance of Rainbow Trout to Varying Salinity

1975 ◽  
Vol 10 (1) ◽  
pp. 118-125 ◽  
Author(s):  
Gérard Leduc ◽  
Kenneth K.S. Chan
Keyword(s):  
Rainbow Trout ◽  
Blood Plasma ◽  
Fresh Water ◽  
Salt Water ◽  
Plasma Osmolality ◽  
Exposure Period ◽  
Chloride Ions ◽  
Salmo Gairdneri ◽  
Cyanide Poisoning ◽  
Flow Through

Abstract The effects of cyanide on iono- and osmoregulation are soon established and last long after the period of exposure to the toxicant is over. The effects are of the order of 4 to 8 percent changes in blood plasma osmolality and chloride ions, changes which are indicative of serious physiological impairment, having costly energetic implications. The deleterious effects of cyanide were detected at concentrations as low as 0.01 mg/l HCN in water of pH 7.5. Juvenile rainbow trout, Salmo gairdneri, were first exposed to various concentrations of cyanide ranging from 0.01 to 0.037 mg/1 HCN for 28 days in fresh water in flow-through aquaria at 10?C. After this exposure period the fish together with untreated fresh water controls were transferred into 18.9 ppt salt water for 260 hours during which blood plasma osmolality and chloride were monitored. By the end of the salinity tolerance tests the poisoned fish had experienced greater loss of water than the controls but no change of chloride were observed. Upon return to fresh water for 100 hours all the fish lost chloride ions, the effect being much greater in the cyanide exposed fish. When the fish were first adapted to salt water then transferred to fresh water cyanide they also experienced loss of chloride and dilution of plasma greater than the controls did.

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