Salinity chlorinity and

Early scientists recognized that standards were needed to determine reliable values of the chlorinity and salinity of seawater. The IAPSO Standard Sea Water Service (originally based in Copenhagen) collected and distributed seawater from the North Atlantic with a known, measured chlorinity. This sample was supplied to oceanographers to standardize the AgNOg solutions used to determine chlorinity in various laboratories. 

As a calibrant solution for the AgNOs titrant, Standard Seawater was prepared that had certified values for both chlorinity and salinity. Unfortunately, the above salinity-chlorinity relationship was derived from only nine seawater samples that were somewhat atypical. It has since been redefined using a much larger set of samples representative of oceanic waters to become... 

Nations Scientific, Education, and Cultural Organization (UNESCO) committee to determine a more precise relation between chlorinity and salinity. The definition of 1969 produced by UNESCO is written in Eq. (8.2) ... 

Water in Industry. Freshwater for industry can often be replaced by saline or brackish water, usually after sedimentation, filtration, and chlorination (electrical or chemical), or other treatments (22). Such treatment is not necessary for the largest user of water, the electric power industry, which in the United States passed through its heat exchangers in 1990 about 40% of the total supply of surface water, a quantity similar to that used for agriculture, and it was 48% of the combined fresh and saline water withdrawals (10). Single stations of 1000 MW may heat as much as 12 Mm /d by as much as 10—15°C. 

Concentrate can be harmful to the environment due to either its higher than normal salinity, or due to pollutants that otherwise would not be present in the receiving body of water. These include chlorine and other biocides, heavy metals, antisealants, coagulants and cleaning chemicals. Of particular concern is the effect of pollutants on delicate ecosystems and endangered or threatened species. However, with appropriate measures in place, the discharge of concentrate to surface water can remain a viable method for seawater desalination plants. 

In general the water soluble inorganics consist of predominantly sodium, chlorine and sulphur (as sulphate ion) with lesser amounts of calcium and magnesium. The Bowmans and Lochiel lignites, both from the St. Vincents Basin, have very high sodium, chlorine and sulphur as a consequence of the saline environment in this region. 

Unlike magnesium, calcium, and strontium, there is no significant trend between dissolved barium and chlorinity or salinity. There is, however, a general inverse correlation between barium and SOq (Figure 7), which is consistent with the hypothesis that equilibrium with respect to barite (BaSOq) may be the factor controlling barium concentrations (Kharaka and Berry, 1974 Hanor, 2001). 

Kamineni D. C. (1987) Halogen bearing minerals in plutonic rocks a possible source of chlorine in saline groundwater in the Canadian shield. In Saline Water and Gases in Crystalline Rocks, Special Paper 33 (eds. P. Fritz and S. K. Frape). Geological Association of Canada, Memorial University, Newfoundland, pp. 69-79. 

Salinity is a measure of the mass of salts dissolved in seawater. It is usually measured in grams of salt per kilogram of seawater. The average salinity of ocean water is about 35 g per kg, so ocean water contains about 3.5% dissolved salts. Most of these salts dissociate in water and are present in the form of ions. Table 26-2 lists the ions in seawater. Note that chlorine and sodium are the most abundant ions in seawater. Although Earth s oceans are vast, the proportions and quantities of dissolved salts are nearly constant in all areas. Indeed, they have stayed almost the same for hundreds of millions of years. Why is this so As rivers, volcanoes, and atmospheric processes add new substances to seawater, elements are removed from the oceans by biological processes and sedimentation. Thus, the oceans are considered to be in a steady state with respect to sahnity. 

Mercury can be used for the extraction of gold. In hospitals and homes, it is still used in thermometers and blood-pressure cuffs, can be found in batteries, switches, and fluorescent light bulbs. Large amounts of metallic mercury are employed as electrodes in the electrolytic production of chlorine and sodium hydroxide from saline. Today, exposure of the general population comes from three major sources fish consumption, dental amalgams, and vaccines. 

Up to 1974, hydrographic data were collected with reversing water bottles and thermometers, and titration of chlorinity for salinity, using certified standard seawater as the reference. From 1974, temperature and salinity profiles were measured with CTD, but up to 1988, nutrient samples were still collected with reversing water bottles. From 1988, CTD-Rosette samplers have been used. An overview of the NERI devices, methods, and uncertainties is given in Table 11.8. 

Ozone can be used to replace chlorine for the sterilization of water. Replacement of chlorine is desirable because chlorination increases the salinity of water. The more salt in the water the less value it has for later use in, for example, irrigation of cropland. When used to sterilize water, chlorine reacts with trace organic compounds to form carcinogenic chlorine compounds such as chloroform. The use of ozone to replace chlorine in water treatment will eliminate chlorination-induced salinity and carcinogenic chlorinated organic compounds. Because of its instability, any residual ozone not consumed in purifying the water rapidly decomposes to ordinary oxygen. 

Temperature, however, is not the only consideration ocean-water density is also influenced by salinity. Seawater contains dissolved ions, mainly sodium and chlorine, and, as a result, is denser than freshwater (typically 1035 kg m 3 compared with 1000 kg m-3). The salinity of seawater is not uniform everywhere in the ocean. Evaporation at the sea surface increases the salinity (as water is evaporated off but dissolved ions are left behind), whereas inputs from rain or river runoff lead to decreased salinity. Salinity is also increased by the formation of sea ice as ice forms, salt is rejected from the freezing water, and the remaining liquid water is enriched in salt. 

The collection of water samples obtained from 05°01 S 32°34 W based on the temperature and salinity data represent sample collections from sub-tropical water, Antarctic intermediate water. North Atlantic deep and bottom water and Antarctic bottom water all the major types of sub-surface water present at this location (13). The lowest strontium/ chlorinity ratio value was found at 4387 meters in the Antarctic bottom... 

Characters and Tests.—Colourless, rhomhoidal crystalline plates, cool saline taste, sparingly soluble in cold water. Its aqueous solution is not affected by silver nitrate or ammonium oxalate. Strongly heated, it fuses, gives off oxygen gas, and leaves a white residue (potassium chloride), which readily dissolves in water, and produces a solution which yields a white precipitate (silver chloride) with silver nitrate, indicating the presence of chlorine, and a yellow precipitate (potassium-platinic chloride) with platinum chloride, showing the presence of potassium. It explodes when triturated in a mortar with sulphur. ... 

Mackay D, Fraser A (2000) Bioaccumulation of persistent organic chemicals Mechanisms and models. Environ Pollut 110(3) 375-391 Mai BX, Fu JM, Sheng GY, Kang YH, Lin Z, Zhang G (2002) Chlorinated and polycychc aromatic hydrocarbons in riverine and estuarine sediments from Pearl River Delta, China. Environ Pollut 117(3) 457-474 Mao XY, Jiang WS, Zhao P, Gao HW (2008) A 3-D numerical study of salinity variations in the Bohai Sea during the recent years. Cont Shelf Res 28(19) 2689-2699... 

Properties Colorless gas R.T. readily liquefied fishy oily rancid sweaty odor saline taste sol. in water, alcohol, ether, benzene, toluene, xylene, chloroform, chlorinated and aromatic soivs. misc. with oxygenated soivs. m.w. 59.11 dens. 0.932 m.p. -117 C b.p. 2.9 C flash pt. 38 F ref. index 1.3443... 

When bubbles are generated by gas other than air (oxygen, hydrogen, nitrogen, chlorine, and carbon dioxide), the behaviors observed depending on pH, salinity, surfactants, and so on are similar to the behaviors of air bubbles, with perhaps an exception for gasses, such as carbon dioxide, which can dissolve easily in water. 

As clearly indicated by Dr. Kalvoda the application of electrochemical processes for the removal of pollutants is mainly concerned with the many sources of toxic heavy metals such as chemical manufactures, metal plating, surface treatment, mining and metallurgical operations. Electrodeposition, electroreduction to insoluble species and the use of sacrificial anodes are the techniques most widely used in this field. The production of chlorine from saline waters in urban or industrial wastewater treatments must also be quoted as a very interesting and practical example of an electrochemical application to the disinfection of different types of water. 

Salinity is defined as the total weight of solids dissolved in 1000 g of water. For example, 35 parts per thousand (96c) salinity is equivalent to 35 g of solids dissolved in 1000 grams of water or a dissolved matter content of 35 000 ppm [12. Salinity usually is determined by measuring chlorinity and then deriving the salinity from the following relation ... 

With the introduction of electrical measurement methods and shipboard computers into oceanography in the 1960s, electrical conductivity replaced chlorinity as the third basic parameter. Two reasons were responsible for this change. Firstly, conductivity can be measured electrically in situ along with pressure and temperature, and salinity and density can be derived on-line once the fundamental determinations needed for such calculations have been made. Secondly, it turned out that based on electrical conductivity, the accuracy in density that could be achieved is an order of magnitude better than that based on chlorinity. 

In the early 1960s, bench salinometers were developed that allowed measurement of the electrical conductivity of a seawater sample relative to that of a standard with high precision. Cox et al. (1967) had related chlorinity and conductivity ratios of seawater to standard seawater at temperatures higher than 10 °C and tabulated their results (UNESCO, 1966). Following their work, the responsible international oceanographic organizations adopted a redefinition of salinity (Wooster et al, 1969). Firstly, it was assumed that salinity was proportional to chlorinity, to be consistent with the assumed constancy of the ionic composition. The constant was chosen so that for 5=35 %o, both the Knudsen formula (3-1) and the new relationship... 

Required Total alkalinity, chlorinity or salinity, initial temperature, pH, and the temperature at which the pH was measured. 

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