The Reduced Strychnine Method for Determining Nitrates in Sea Water

1936 ◽  
Vol 2 (1) ◽  
pp. 1-11 ◽  
Author(s):  
William A. Riddell
Keyword(s):  
Hydrochloric Acid ◽  
Sea Water ◽  
Nitrate Concentration ◽  
Comparison Standard ◽  
Strait Of Georgia ◽  
Small Glass ◽  
Random Samples

A satisfactory procedure for the estimation of the dissolved nitrates in the waters of the strait of Georgia is described involving the use of a Duboscq colorimeter. Seven ml. of sample and reagent plus 3 drops of concentrated hydrochloric acid develop a satisfactory colour. A large number of small glass vials are used in place of the regular Duboscq cups. Standards are prepared from random samples of sea water. The proportionality between colour developed and nitrate concentration is practically linear up to 4.8 mg. of NO3 ion per litre but the factor is not 1. This necessitates an appreciable correction for all observed concentrations which differ greatly from that of the comparison standard.

Taste by Touch: Some Experiments with Octopus

1963 ◽  
Vol 40 (1) ◽  
pp. 187-193
Author(s):  
M. J. WELLS
Keyword(s):  
Hydrochloric Acid ◽  
Fresh Water ◽  
Sea Water ◽  
Olfactory Organ ◽  
Distilled Water ◽  
Quinine Sulphate ◽  
Human Tongue ◽  
Half Strength

1. A method of teaching Octopus chemotactile discriminations is described. 2. The animals can be shown to be capable of distinguishing by touch between porous objects soaked in plain sea water and sea water with hydrochloric acid, sucrose or quinine sulphate added. 3. They can detect these substances in concentrations at least 100 times as dilute as the human tongue is capable of detecting them in distilled water. 4. They can be trained to distinguish between equimolar (0.2 mM) solutions of hydrochloric acid, sucrose and quinine. 5. They can also be trained to distinguish between sea water and fresh water or half-strength sea water or sea water with twice the usual quantity of salt. 6. The function of the ‘olfactory organ’ is discussed. 7. Chemotactile learning is discussed in relation to the means by which Octopus finds its way about the territory around its ‘home’

scholarly journals Evaluation of bottled water quality by determining nitrate concentration

2020 ◽  
Vol 18 (5) ◽  
pp. 681-691
Author(s):  
María Susana Fortunato ◽  
Ana Julieta González ◽  
María Florencia Tellechea ◽  
Mariano Humberto Reynoso ◽  
Favia Vallejos ◽  
...  
Keyword(s):  
Water Quality ◽  
Buenos Aires ◽  
Nitrate Concentration ◽  
Public Awareness ◽  
Bottled Water ◽  
Buenos Aires Province ◽  
Water Access ◽  
Limit Value ◽  
Random Samples ◽  
Consumption Habits

Abstract The presence of nitrate in sources of drinking water is a matter of concern because of its potential risk for human health. In many countries like Argentina, an increasing proportion of the population chooses to consume bottled water, among other reasons, for lack of water access. The present study was conducted (a) to evaluate the quality of bottled waters by determining nitrate concentration, (b) to relate bottled water quality with water access, (c) to analyze public awareness about bottled water quality and consumption habits of the population in the urban area of Buenos Aires. Two locations were selected, Ciudad Autónoma de Buenos Aires (C.A.B.A.) and Malvinas Argentinas in Buenos Aires Province (PBA), with percentages of water access of 99.6% and 8.8%, respectively. Random samples from both locations (n = 100) were analyzed. A survey was conducted in order to inquire about perception of population on bottled water quality and their consumption habits. In C.A.B.A., no sample exceeded the 45 mg/L limit value in force in Argentina, while in Malvinas Argentinas, 34% of the brands analyzed showed values above it. The survey revealed that 71.7% of people consume bottled water. While people in C.A.B.A. do so mainly out of habit, safety is the priority in PBA.

THE EPITHALASSA OF THE STRAIT OF GEORGIA: SALINITY, TEMPERATURE, pH AND PHYTOPLANKTON

1931 ◽  
Vol 5 (2) ◽  
pp. 231-284 ◽  
Author(s):  
A. H. Hutchinson ◽  
C. C. Lucas
Keyword(s):  
Great Basin ◽  
Sea Water ◽  
Economic Value ◽  
River Mouth ◽  
Water Source ◽  
Large River ◽  
Exact Nature ◽  
Fraser River ◽  
Fish Food ◽  
Strait Of Georgia

The investigation was initiated in order to determine the extent of the Fraser River's effect on temperature, salinity, currents, and fish food, probable factors in the direction of salmon migrations. A correct valuation of the Fraser River in these respects has necessitated a survey of the Strait of Georgia waters and an estimate of the relative importance of water entering the Strait from other sources, from the sea through the passes and from other rivers. It is believed that the data presented may have a potential economic value as a basis for a further knowledge of the habits of fish, the establishment of oyster beds, the development of clam beaches and of crab and shrimp industries and the location of summer resorts. Conclusions regarding the interrelations of salinity, temperature, pH, tidal movements and phytoplankton, may be of scientific interest.The following conclusions discussed in the paper may be emphasized: (1) The Strait of Georgia is a great basin, connected with the sea by narrow passes, which receives water from a number of large rivers, notably the Fraser River. (2) The river water is conserved during the summer and forms a marked upper layer, epithalassa, which is characterized by low salinity and high temperature. The increase in temperature as compared with sea water may amount to 10 °C. or 18° F. (3) Throughout the greater part of the region this epithalassa has a stability which is sufficient to resist tidal and wave movements. (4) Since time is a factor, the heating effect of the sun, insolation, upon the epithalassa becomes most evident at regions some distance from the river mouth. In the case of a large river, as the Fraser, this distance may exceed ten miles. (5) Abundant fish food in the form of plankton is present and the amount is greatest at the regions where the most complete mixing of the river and of the sea water takes place. Evidently each water source contributes certain conditions or factors favorable for plankton growth. Further investigation to determine the exact nature of these conditions is in progress. (6) Mass movements of the epithalassa accompany tidal changes, resulting in variations of salinity, temperature and plankton at any point according to the source of the translocated water and the phase of the tide.

scholarly journals The ultra-violet absorption of sea water

1961 ◽  
Vol 41 (3) ◽  
pp. 591-597 ◽  
Author(s):  
F. A. J. Armstrong ◽  
G. T. Boalch
Keyword(s):  
Surface Waters ◽  
Coastal Waters ◽  
Sea Water ◽  
Nitrate Concentration ◽  
Ultra Violet ◽  
Short Wave ◽  
Atlantic Water ◽  
Seasonal Effect ◽  
High Nitrate Concentration ◽  
The Difference

SUMMARYMeasurements of the ultra-violet absorption spectra between 200 and 400 mix, have been made with a spectrophotometer. At short wave-lengths natural sea water has double the absorbancy of artificial sea water. The difference in samples from shallow depths is ascribed to organic material, of which part may be the Gelbstoff of Kalle. Regional variations have been found, coastal waters having higher U.V. absorptions. A small seasonal effect with an increase in absorbancy in summer in the English Channel has been seen. In deep Atlantic water increased absorption below 235 m/x may be due to its high nitrate concentration. At longer wave-lengths absorbancies were less than in surface waters. Measurements of U.V. absorption may supplement other physical methods of characterizing water masses.

scholarly journals Optical Fiber Sensors for the Detection of Hydrochloric Acid and Sea Water in Epoxy and Glass Fiber-Reinforced Polymer Composites

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 379 ◽  
Author(s):  
Cristian Marro Bellot ◽  
Marco Sangermano ◽  
Massimo Olivero ◽  
Milena Salvo
Keyword(s):  
Hydrochloric Acid ◽  
Optical Fiber ◽  
Glass Fiber ◽  
Structural Integrity ◽  
Sea Water ◽  
Optical Fiber Sensors ◽  
Fiber Reinforced Polymers ◽  
Fiber Reinforced ◽  
Fiber Sensors ◽  
Glass Fiber Reinforced

Optical fiber sensors (OFSs), which rely on evanescent wave sensing for the early detection of the diffusion of water and hydrochloric acid through glass fiber-reinforced polymers (GFRPs), have been developed and tested. Epoxy and GFRP specimens, in which these sensors were embedded, were subjected to tests in artificial sea water and hydrochloric acid. The sensors were able to detect the diffusion of chemicals through the epoxy and GFRP samples on the basis of a drop in the reflected signal from the tip of the optical sensor probe. Water and hydrochloric acid diffusion coefficients were calculated from gravimetric measurements and compared with the experimental response of the OFSs. Furthermore, mechanical tests were carried out to assess the influence of the sensors on the structural integrity of the GFRP specimens.

A Horizontally Resolving Physical–Biological Model of Nitrate Concentration and Primary Productivity in the Strait of Georgia

1993 ◽  
Vol 50 (7) ◽  
pp. 1456-1466 ◽  
Author(s):  
M. A. St. John ◽  
S. G. Marinone ◽  
J. Stronach ◽  
P. J. Harrison ◽  
J. Fyfe ◽  
...  
Keyword(s):  
Surface Layer ◽  
Water Column ◽  
Primary Productivity ◽  
River Runoff ◽  
Nitrate Concentration ◽  
Energy Requirement ◽  
Fraser River ◽  
Strait Of Georgia ◽  
Wind Events ◽  
Wind Mixing

Model simulations revealed that wind mixing was the dominant physical mechanism that added nitrate to the surface layer and subsequently enhanced primary productivity in the Strait of Georgia. Simulations of high Fraser River runoff showed that the enhanced stability of the water column in the vicinity of the riverine plume made wind mixing of nutrients into the surface layer more difficult. We propose that this increase in stability results in an earlier onset of the spring bloom in regions influenced by Fraser River runoff. During the summer, an increase in the buoyancy of surface water due to the freshwater plume reduces nitrate concentration in the surface layer and thereby limits primary production in the plume area. The reduced impact of wind events on nitrate fluxes is the result of a greater energy requirement to break down the more buoyant surface layer. Results indicate that during the fall, when light is again limiting and surface nitrate concentrations increase due to wind mixing by fall storms, the freshwater runoff from the Fraser River results in a more stable water column (similar to the spring situation) in the southern Strait, resulting in the potential for a fall bloom.

scholarly journals THE ACCUMULATION OF ELECTROLYTES

1938 ◽  
Vol 21 (6) ◽  
pp. 767-773 ◽  
Author(s):  
A. G. Jacques ◽  
W. J. V. Osterhout
Keyword(s):  
Sea Water ◽  
Nitrate Concentration

The nitrate concentration in the sap of Valonia macrophysa, Kütz., is at least 2000 times that of the sea water, and in Halicystis Osterhoutii, Blinks and Blinks, at least 500 times that of the sea water.

scholarly journals Assessment of Seawater Intrusion into Shallow Coastal Aquifer in Kanyakumari District, Tamilnadu, India

2020 ◽  
Vol 9 (3) ◽  
pp. 3006-3014
Keyword(s):  
Seawater Intrusion ◽  
Sea Water ◽  
Magnesium Carbonate ◽  
Research Area ◽  
Quality Parameters ◽  
Shallow Aquifer ◽  
Quality Of Water ◽  
Random Samples ◽  
Calcium Magnesium

Improved use of groundwater is often causing intrusion of seawater. The intrusion of seawater also takes place in coastal areas. In this analysis, the distribution and the levels of intrusion in the research area (Kanyakumari district, Tamilnadu, India) are determined. The test was done using random samples at a period of 15 days in which 30 different samples were taken in 5 different locations with a certain distance from the seashore, then chemical analysis including pH, electrical conductivity (EC), total dissolved solids (TDS), chloride, sodium, calcium, magnesium, carbonate, and bicarbonate water quality parameters were carried out. Chloride Bicarbonate Ratio was used for the calculation of the penetration rate of the seawater, and subsequently chloride and electric conductivity were defined as type and quality of water characters. The results showed that the shallow aquifer was intruded by seawater at several sample levels, which was included in the normal to high intrusion classification. The sea water intrusion was classified as freshwater to saltwater, the concentrations in chloride ranged from 159 to 6021 mg / L. The ratio of bicarbonate chloride was 0.28 to 21.46, normally above 15.5, indicating that groundwater was disturbed. As a result, in comparison to standards or other seawater intrusion indicators, Rajakamangalam-well 1 (RM-W1) has been affected by seawater intrusion highly.

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