If sea water contains ammonia as one of it's pollutants, it is supposed that some of the ammonia enters the product water at a desalination plant using an evaporation method. Then, the rate of ammonia in the product water can be estimated with the vapor-liquid (V-L) equilibrium which must include the chemical equilibrium of ammonia in the brine.
In this paper, we present the V-L equilibrium equation on an ammonia-saline water system which includes the chemical eqilibrium. In order to predict theoretically the behavior of ammonia in the plant, we calculated the equilibrium values for the pH levels, at the temperatures and the salinities which were nearly the same as the those in the operation conditions of a desalting evaporator.
As a result, the effects of temperature, pH and salinity to the V-L equilibrium in this system were clarified theoretically for the first time by considering the chemical equilibrium, and it was found that this equation could also be used for predicting exactly the behavior of ammonia in a desalting evaporation plant. Also, in the discussion about the equation and the results, it became clear that the chemical equilibrium had to always be considered in the V-L equilibrium equation of a chemical substance which ionized and/or formed the complex in a solution like ammonia, and that the equation of ammonia (eq. 12) could be used for the substance only by making a partial amendment of the equation to be an appropriate form for the substance.

View full abstract

Both inorganic and organic carbon dissolved in sea water were studied. New equations concerningthe dissociation of carbonic acid in sea water were introduced which enabled the calculationof each concentration of free carbonic acid, bicarbonate and carbonate ions. By these equations, the quantitative relation between carbonate alkalinity (CA) and total inorganic carbon concentration (C) was obtained. In addition, equations to estimate ratio of simultaneous changes in carbonate alkalinity and calcium content were given which indicate that the ratio is not constant (0.5), but changes widely from 0.1 to 1.0.
It is considered that total content of carbon dissolved in inorganic and organic forms is nearly constant in the entire ocean owing to longer residence time of carbon in the ocean.
It is postulated that the concentration of both inorganic and organic carbon can be expressed as a sum of each own constant term (primary concentration) and variable terms relating to biological and biochemical effects. The constancy of total carbon concentration was proved experimentally by employing dry combustion method of analysis of organic carbon.
In the upper layer (0-1,000 m), carbon concentration is mainly controlled by biological production including shell formation, while in deep layer, by oxidative decomposition of organic matters and solution of calcium carbonate. The concentrations of inorganic and organic carbon in the upper layer are 1.9 to 2.1 mg at/kg and 0.27 to 0.35 mg at/kg respectively. In deep layers, 2.2 to 2.35 mg at/kg for inorganic and 0.07 to 0.10 mg at/kg for organic carbon. It was estimated thatprimary concentrations of inorganic and organic carbon are respectively 2.15 mg at/kg and 0.26mg at/kg, and the total concentration of dissolved carbon is 2.41 mg at/kg. Since two atoms of oxygen forms one molecule of carbon dioxide, and 80% of AOU is used for oxidation of organic carbon, 0.4 AOU is consumed through reproduction of inorganic carbon. The ratio of analytical results of organic carbon by dry combustion and wet oxidation methods was about 2.5 near the surface and 1.3-1.4 in middle and deep layers.
In the last chapter, equations to express the ratio of inorganic carbon and nitrogen concentration were deduced which agreed well with observations. As to organic carbon and nitrogen, the constantratio of 9.3 was proposed. Finally, it was suggested in this paper to revise substantially socalled radio-carbon age of sea water.

View full abstract