scholarly journals Observations on the blood of Certain Ascidians, with Special Reference to the Biochemistry of Vanadium

1939 ◽  
Vol 16 (4) ◽  
pp. 499-523
Author(s):  
D. A. WEBB
Keyword(s):  
Sulphuric Acid ◽  
Sea Water ◽  
Chain Complex ◽  
Pigment Cells ◽  
Bile Pigment ◽  
Vanadium Compounds ◽  
Straight Chain ◽  
Orange Pigment ◽  
Theoretical Considerations

The blood of a number of species of Ascidiacea has been examined with reference to the presence of the vanadium chromogen described by Henze, and the results are discussed in connexion with the data available from other authors. The chromogen is always contained, together with sulphuric acid, in a special type of cell described as a vanadocyte. These are found only in the hcidiidae and Perophoridae, though members of certain other families contain vanadium in some other form. The distribution within the group of sulphuric acid in vesicular cells of the blood and test is also discussed. There is no reason to suppose that the pigments of Ascidians, other than the chromogen itself, are vanadium compounds. A curious type of cell inclusion from the orange pigment cells of Ascidia mentula is described. Experimental evidence and theoretical considerations are brought forward to show that the vanadium chromogen is not in any sense a respiratory pigment. At present no function can be ascribed to it. I t is not a protein or porphyrin compound, but seems to consist of vanadium in association with a straight chain complex of pyrrol rings, comparable perhaps to a bile pigment. It seems possible that sea water provides a sufficiently rich source of vanadium to account for the amounts absorbed. The phylogenetic aspects of these facts are considered in relation to Berrill's recentre-classification of the Ascidiacea. The presence of vanadium is a primitive character which has been lost in the more specialized families.

The influence and importance of daily weather conditions in the supply of chloride, sulphate and other ions to fresh waters from atmospheric precipitation

1958 ◽  
Vol 244 (1236) ◽  
pp. 140-140
Keyword(s):  
Sulphuric Acid ◽  
Atmospheric Pollution ◽  
Natural Waters ◽  
Sea Water ◽  
Atmospheric Precipitation ◽  
Weather Conditions ◽  
Sea Spray ◽  
Lake District ◽  
The South ◽  
Soil Weathering

This paper deals with chemical analyses for hydrogen, sodium, potassium, calcium, chloride, sulphate and nitrate ions in daily precipitation samples collected in the English Lake District, and examines the correlations of these analyses with ( a ) one another, ( b ) the amount of precipitation, ( c ) wind direction, ( d ) wind velocity, and ( e ) temperature. Highly significant correlations are found between estimates for H, K, Ca, NO 3 and SO 4 ions, and atmospheric pollution appears to supply much of the sulphate in Lake District rain, since it comes largely as sulphuric acid from the south-east. The correlation between Na and Cl is also extremely close, with the proportion between the two ions very similar to that in sea water. Since these two ions are supplied mainly from the south-west, in amounts which are greatly increased by high winds, sea spray may be inferred as the principal source. Nevertheless, evidence is presented for some small supply from atmospheric pollution, and it is furthermore suggested that mixed droplets of sea salt and sulphuric acid may, upon abstraction of moisture by freezing or evaporation, release gaseous hydrogen chloride to the air and so alter the balance of Na and Cl in precipitation. The supply of Na and Cl is also considerably higher in cold than in warm weather, a phenomenon possibly connected with stormier conditions and greater evaporation over the Atlantic Ocean. The atmospheric contribution of ions to natural waters via precipitation is shown to be of great importance, in particular to bog pools, to upland tarns on hard rocks, and to the soil solution in highly organic mor humus layers overlying heavily leached hillside soils. Sodium and chloride in most surface waters appears to be almost wholly supplied by sea spray, while calcium and magnesium bicarbonates are the main products of soil weathering. A net loss of rain acids is evident in all soil waters, although some may be more acid than normal rain water owing to considerable concentration by evaporation. The soil waters are relatively rich in potassium, presumably supplied from decaying vegetation.

Santa Cesarea Terme, a sulphuric acid speleogenetic system intensely influenced by marine waters

2021 ◽  
Author(s):  
Ilenia M. D'Angeli ◽  
Jo De Waele ◽  
Adriano Fiorucci ◽  
Bartolomeo Vigna ◽  
Stefano M. Bernasconi ◽  
...  
Keyword(s):  
Sulphuric Acid ◽  
Southern Italy ◽  
Sea Water ◽  
Sampling Site ◽  
Seasonal Effects ◽  
Water Sampling ◽  
Marine Waters ◽  
Water Head ◽  
Marine Influence ◽  
By Products

<p>Santa Cesarea Terme (SCT) karst system opens along the Adriatic coastline of Apulia (southern Italy) and is composed of four sub-horizontally caves Fetida, Sulfurea, Gattulla and Solfatara. Being influenced by rising sulphidic waters, it is used as thermal spa for human health treatments. The caves show interesting signs of hypogene sulphuric acid speleogenetic (SAS) activity such as peculiar morphologies and mineralogical by-products. From the geomorphological standpoint it is possible to observe ceiling cupolas, megacusps (former megascallops), rising channels, submerged feeders, weathered walls, replacement pockets, whereas for mineralogy sulphur, gypsum and jarosite deposits have been recorded. Despite the presence of extensive SAS features, SCT is also intensely influenced by marine water.</p><p>All these observations induced us to conduct a long-lasting (2015-2018) geochemical monitoring to understand intensity and tendency of the two main domains (rising acidic vs. marine).</p><p>Water sampling was done every 3-4 months at 4 sites in Fetida (2 in areas influenced by sea water movements, and 2 in the innermost zone, less but still influenced by sea), and 1 site in Gattulla. Moreover, 1 sampling site located along the coastline (sea water) was constantly monitoring for comparative reasons.</p><p>Collected groundwaters exhibit mean temperatures of 23 °C (7 °C higher than average annual air temperature) and circumneutral pH. All samples belong to the Na-Cl-SO<sub>4</sub> type of waters. Sea waters display the highest pH (ranging between 8.15 and 8.20), [Na<sup>+</sup>], [K<sup>+</sup>], [Mg<sup>2+</sup>], [Cl<sup>-</sup>], [SO<sub>4</sub><sup>2-</sup>], and total dissolved solids (TDS), and on the other hands one of the innermost sampling site in Fetida Cave showed the highest values of temperature (29 °C), [HS<sup>-</sup>], [Ca<sup>2+</sup>] and the lowest pH (6.76). In addition, the Ba<sup>2+</sup>/Sr<sup>2+ </sup>ratio compared with Ca<sup>2+</sup>/HCO<sub>3</sub><sup>-</sup> or Ca<sup>2+</sup>/SO<sub>4</sub><sup>2-</sup> clearly exhibit the presence of two main domains: rising acid and marine. In particular, the samples collected in the Adriatic Sea are always in the domain of marine influence, whilst all the others from Gattulla and Fetida, depending on sampling conditions (tides, waves, etc..), can fall in both domains.</p><p>Our investigations demonstrated rising sulphidic fluids to reach the surface through deep tectonic fractures and karst flowpaths, but seasonal effects due to modest water head variations (tides) and meteomarine conditions affect the geochemical variability, even in the innermost portion of the caves, inducing these slightly thermal acidic fluids to partially mix with marine waters.</p>

Determination of nitrate in sea water by cadmium-copper reduction to nitrite

1967 ◽  
Vol 47 (1) ◽  
pp. 23-31 ◽  
Author(s):  
E. D. Wood ◽  
F. A. J. Armstrong ◽  
F. A. Richards
Keyword(s):  
Standard Deviation ◽  
Sulphuric Acid ◽  
Sea Water ◽  
Colorimetric Method ◽  
Zinc Powder ◽  
Small Samples ◽  
Nitrosyl Chloride ◽  
Sensitivity Limit ◽  
High Concentrations

An accurate, dependable determination of 0–60 μg-at./l. of NO−3-N in sea water has been developed. The sample is treated with tetrasodium ethylenediaminetetraacetate solution and passed through a column of copperized cadmium filings. A nearly quantitative reduction of nitrate to nitrite results. Nitrite is then determined by a diazotization method. Neither sulphide nor high nitrite concentrations interferes. Approximately eight samples per hour per column can be analysed with a standard deviation of 0.12 μg-at./l. at the 20 μg-at./l. level.IntroductionAccurate determinations of nitrate ions in sea water have been difficult, especially under shipboard conditions.The colorimetric method described by Harvey (1926, 1930) and improved by Cooper (1932), Zwicker & Robinson (1944), and others uses strychnidine in concentrated sulphuric acid to produce a red colour. The reagent lacks reliable sensitivity, because it is dependent on the rates of mixing and cooling.In a method by Armstrong (1963), the absorbance of nitrosyl chloride in the UV region is measured with a spectrophotometer. While the method is good for small samples containing high concentrations of nitrate, the use of concentrated sulphuric acid and lack of sensitivity limit its use in routine analysis.A method in which nitrate is quantitatively reduced to nitrite would be advantageous, because nitrite can be readily determined by the sensitive diazotization method proposed by Griess (1879). Several such methods have been proposed. FØyn (1951), Vatova (1956), and Chow & Johnstone (1962) used zinc powder for the reduction, but the reduction is sensitive to temperature, and it is necessary to centrifuge or filter each sample.

Theoretical considerations about the reactions of calcification in sea water

1999 ◽  
Vol 63 (3-4) ◽  
pp. 213-224 ◽  
Author(s):  
Claire Copin Montégut ◽  
Gérard Copin Montégut
Keyword(s):  
Sea Water ◽  
Theoretical Considerations

Selective leaching of a polymetallic complex ore by sulphuric acid and thiourea mixed with sea water

1995 ◽  
Vol 38 (2) ◽  
pp. 189-204 ◽  
Author(s):  
Djamal-Eddine Akretche ◽  
Sofia Kara Slimane ◽  
Hacène Kerdjoudj
Keyword(s):  
Sulphuric Acid ◽  
Sea Water ◽  
Selective Leaching

scholarly journals The determination of silicate in sea water

1951 ◽  
Vol 30 (1) ◽  
pp. 149-160 ◽  
Author(s):  
F. A. J. Armstrong
Keyword(s):  
Sulphuric Acid ◽  
Sea Water ◽  
Picric Acid ◽  
Colorimetric Method ◽  
Ammonium Molybdate ◽  
Potassium Chromate ◽  
Distilled Water ◽  
Yellow Colour ◽  
Standard Solutions

Silicon in sea water may be present in suspension, in particles of clay or sand, as a constituent of diatoms, etc., or in solution. Some silicon in solution occurs in the form of silicate. This is usually estimated by the colorimetric method of Diénert & Wandenbulcke (1923), which makes use of the yellow colour of the silicomolybdic acid which is formed when ammonium molybdate and sulphuric acid are added to the water (Atkins, 1923). The colour may be compared with that of standard solutions of picric acid (Diénert & Wandenbulcke, 1923) or potassium chromate (Swank & Mellon, 1934). The method is simple but the colour in sea water is often faint and is not easy to match visually, nor is its intensity strictly proportional to the concentration of silicate. Less colour is produced in sea water than in standard solutions made with distilled water and this ‘salt error’ must be allowed for (Brujewicz & Blinov, 1933; Wattenberg, 1937; Robinson & Spoor, 1936).

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