Dissolved Oxygen in Water

M. A. IT insky and G. Knorre proposed l-nitroso-2-naphthol as a reagent for cobalt and Zh.I. lotsich - magnesium diiodine acetylene as a reagent for carbonyl group. F.M. Flavitsky developed a method for qualitative analysis based on solid substances as well as a portable laboratory for qualitative analysis. G.V. Khlopin proposed a method for determining oxygen dissolved in water. 

DO Dissolved Oxygen - a measure of the oxygen dissolved in water expressed in milligrams per liter. 

KLa is the volumetric oxygen mass transfer coefficient, owing to the oxygen transfer from the gas phase or air, c, the surface of the cells, cx or to the transfer of oxygen dissolved in water to the surface of the cells. 

Closely related to the London interaction is the dipole-induced-dipole interaction, in which a polar molecule interacts with a nonpolar molecule (for example, when oxygen dissolves in water). Like the London interaction, the dipole—induced-dipole interaction arises from the ability of one molecule to induce a dipole moment in the other. However, in this case, the molecule that induces the dipole moment has a permanent dipole moment. The potential energy of the interaction is... 

Solutions Solutions are homogeneous forms of matter that may be composed of a solid dissolved in a liquid - such as common salt dissolved in water a gas dissolved in a liquid - for example, oxygen dissolved in water or a solid dissolved in another - for example, carbon dissolved in iron in some alloys of this metal. The composition and properties of each solution are determined by the nature of the components and the relative amount of each component in the solution (see Table 2). 

There is a longstanding demand for a simple and portable instrument for the detection and measurement of oxygen dissolved in water. Suitable electrodes have been developed and more recently have been ingeniously used as the basis for a range of biochemical sensors. 

Tap water is always saturated with oxygen, the amount depending on the temperature. The maximum concentration of oxygen in water - about 0.02 mol dm-3 - occurs at a temperature of 3 °C. The amount of oxygen dissolved in water will decrease below this temperature, since (partition) decreases. Accordingly, much dissolved oxygen is expelled from solution as the water freezes, merely to keep track of the constant decreasing value of K(partition). 

Fluorescence quenching resulting from the collision of the analyte with a fluorescent compound (see Chapter 4). This method is particularly well suited to the detection of gases such as oxygen (dissolved in water or blood), SO2, H2S, ammonia, HC1, Cl2, chlorocarbons, etc. 

Trickle bed gas absorber-reactor. Sulfur dioxide is to be removed from a gas by passing the gas and water through a bed of highly porous activated carbon kept at 25°C. In this system sulfur dioxide and oxygen dissolve in water and react on the solid to give sulfur trioxide, as follows ... 

Acidity problems tend to be localized in bodies of water near industrial operations that discharge acidic materials or near active or abandoned mines. Acids form when water flows through all kinds of mines, including coal mines and mines for the extraction of various metals. Probably the most common acid-forming process in such cases occurs when iron pyrites (FeS2), found in coal seams and in many metal mines, is oxidized by atmospheric oxygen or oxygen dissolved in water to produce iron(II) sulfate ... 

Another correlation for estimating Henry s constant for oxygen dissolved in water in the temperature range 100 200 °C has been presented by Wu et al. (2003) ... 

Remember, induced dipoles are only temporary. If the water molecule in Figure 7.4b were removed, the oxygen molecule would return to its normal, nonpolar state. As a consequence, dipole-induced dipole attractions are weaker than dipole-dipole attractions. Dipole—induced dipole attractions are strong enough to hold relatively small quantities of oxygen dissolved in water, however. As this chapter s introduction discusses, this attraction between water and molecular oxygen is vital for fish and other forms of aquatic life that rely on molecular oxygen mixed in water. 

Aquatic animals breathe the oxygen dissolved in water. The oxygen in water comes from the water plants. 

Oxygen dissolves in water according to Henry s law, The partial pressure of a gas in a liquid is equal to the partial pressure of the gas above the liquid. Therefore, the DO concentrations depend on the atmospheric pressure. They are also temperature-dependent as the solubility of gases decreases with increasing temperature. Another factor that decreases the solubility of oxygen in water is the dissolved salt content the more salts are dissolved, the less room for oxygen to dissolve. 

The electrolysis of water proceeds without any side reactions and also the current losses which are caused by dissipation and by the recombination of hydrogen and oxygen dissolved in water are low. The current efficiency at normal pressure is, therefore, very good, reaching about 99 per cent. If electrolysis is carried out at a higher pressure the current efficiency is somewhat lower, as more gas is dissolved in the electrolyte which causes an increased quantity of the recombined hydrogen and oxygen. 

In the absence of a sacrificial metal, oxygen dissolved in water may react with the iron casing of the heater. One product formed is iron(II) hydroxide (Fe(OH)2). Which element is oxidized and which is reduced in this reaction ... 

Miss Katherine Williams, who worked for many years in the department on the chemistry of cooked fish, came first under Ramsay. It is said that he suggested that she should repeat the Cavendish experiment on air, but she chose something easier, the determination of the oxygen dissolved in water (p. 69). Later, when he and Miss K. Williams, at Bristol, were investigating an alleged allotropic form of nitrogen (Proc. Chem. Soc., 1886), he says that he suggested that she should... 

Figure 12 shows examples of the potential applications of substituted polyacetylenes studied, especially poly(4a). Oxygen enrichment (26-28, 31-33) is applicable to combustion furnaces, car engines, and respiration-aiding apparatus. The transport of oxygen dissolved in water (33, 34) can be applied to contact lenses and artificial lungs. Liquid-mixture separation (30,... 

Radiorelease methods are based on the same principle the substance to be determined is brought into contact with another substance containing a radionuchde reagent, and by their interaction a certain amount of the radionuclide is released and measured. For this method substances loaded with Kr (radioactive kryptonates), for example krypton clathrates, may be applied. By reaction with oxygen Kr is released and can be measured continuously. Oxygen dissolved in water can be measured by reaction with jj deposited on Cu 204 jj jg oxidized and released into the... 

An early example of a patent on membrane contactor for gas transfer is in Ref. [12]. Harvesting of oxygen dissolved in water and discharging of CO2 to the water is presented in Ref. [13]. A membrane device to separate gas bubbles from infusion fluids such as human-body fluids is claimed in Ref. [14]. A hollow fiber membrane device for removal of gas bubbles that dissolve gasses from fluids delivered into a patient during medical procedures is disclosed in Ref. [15]. Membrane contactors have also found application in dissolved gas control in bioreactors discussed in Refs. [16-17]. 

The Henry s law constant for oxygen dissolved in water is 4.34 X 10 atm at 25°C. If the partial pressure of oxygen in air is 0.20 atm under ordinary atmospheric conditions, calculate the concentration (in moles per liter) of dissolved oxygen in water that is in equilibrium with air at 25°C. 

The colour reaction with Indigo Carmine is useful for determining oxygen dissolved in water [2-4]. The yellow reduced form of the reagent (leucobase) turns red (Xmax = 555 nm) under the influence of oxygen. Leuco forms of other dyes have also been proposed for determining oxygen. These include Methylene Blue [4-7], Berbelin Blue (formula 35.1) [8], Methyl Red [9], and Safranine T [4]. 

A solution with oxygen dissolved in water containing 0.5 mg O2/100 g of H20 is brought in contact with a large volume of atmospheric air at 283 K and a total pressure of 1 atm. The Henry s law constant for the oxygen-water system at 283 K equals 3.27 x 104 atm/mole fraction. 

The oxidation of Cr(III) to Cr(IV) by oxygen dissolved in water is very slow and takes place only in alkaline media. On the other hand, reduction of Cr(VI) in natural waters by bivalent iron is possible especially in acid media and by sulphites and hydrogen monosulphide. The maximum concentration of Cr(VI) in drinking water permitted by the World Health Organization is 0.05 mg. ... 

---