Saline Water Distillation

Saline Water Distilletlon The scaling problem is of particular significance in water desalination because the very low cost velue of the fresh water product restricts treatment methods. Scale formation cannot be tolerated to any extent because of its effect on production rate and energy consumption. Current practice for all distillation methods relies on one of two approaches for controlling calcium carbonate  

No economical control method is available for calcium sulfate other than ensuring that the concentration-temperature process path is within the solubility confines of the various crystalline modification of calcium sulfate. The limiting top temperature at which seawater mey be evaporated without calcium sulfate scale deposition is of major design significance. 

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Bodell, B.R. Silicon rubber vapor diffusion in saline water distillation. United States Patent Application Serial No 285,032, 1963. 

Saline Water Distillation-Scaling Experiments Using the Spray Evaporation Technique... 

Much is being learned of the role of dissolved oxygen, pH, and other properties of saline water as they affect the life of materials of construction. We are fast approaching the time when carbon steel, cast iron, and plastics can be used for saline water distilling plants. 

Therefore, 12.37 kg saline water are needed in this case to produce 1 kg distillate. This high dow rate incuts corresponding pumping equipment and energy expenses, sluggish system dynamics, and, because the stream level depth is limited to about 0.3—0.5 m for best evaporation rates, also requites large evaporator vessels with their associated expense. 

The generated water vapor rises through a screen (demister) placed to remove entrained saline water droplets. Rising further, it then condenses on the condenser tube bank, and internal heat recovery is achieved by transferring its heat of condensation to the seawater feed that is thus being preheated. This internal heat recovery is another of the primary advantages of the MSF process. The energy performance of distillation plants is often evaluated by the performance ratio, PR, typically defined as... 

Because water of depths below about 2 m does not absorb much solar radiation direcdy, the radiation is absorbed and converted to heat primarily in the basin floor, which thus should have high radiative absorptance in the solar radiation spectmm. It is also noteworthy that if the stUl is designed to have low heat losses to the ambient, and if the ambient temperature drops, distillation will continue for some time even in the absence of solar energy input, because the saline water may remain warmer than the condensing glass surface and thus continue evaporating. 

Cleanse the wound using standard wound cleansing procedures and mild-cleansing agents (e.g., rinsing with saline or distilled water). 

Compound Distilled Water solubility (mg/L) Seawater solubility (mg/L) Freshwater CCAS (mg/L) Saline water CCAS (mg/L)... 

As we have discussed already, the property of membrane semipermeability applies to all sorts of systems. Likewise, reverse osmosis may be applied to a wide variety of systems. An application that has attracted a great deal of interest in recent years is the production of potable water from saline water. Since no phase transitions are involved as, for example, in distillation, the method offers some prospect of economic feasibility in coastal regions. 

In distillation, impurities from saline water or brine arc removed by boiling the saline water, collecting the waler vapor and then cooling the... 

A number of other desalination processes, such as freezing, membrane distillation, and solar humidification, have been used to desalt saline waters. Based on their commercial success, these processes can be considered as minor desalination processes. 

The conversion of saline water to fresh water by freezing is relatively new, but it is believed to have great potential. Theoretically, freezing has several inherent advan-iages over conventional distillation processes—for example, the lesser tendency toward... 

Other pilot plant activity includes testing of solar stills at an experimental station near Daytona Beach, Fla. At the Bureau of Reclamation Laboratories in Denver, the Office of Saline Water has two electrodialysis units, one built by Ionics, Inc., Cambridge, Mass., and the other by the Central Technical Institute, T.N.O., of the Netherlands. A Japanese electrodialysis unit is on order and will be tested at the Denver Laboratories. Various types of membranes are also being tested at Denver. Distillation experiments are continuing in research facilities located at Wrightsville Beach, N. C. 

Badger-Hickman Centrifugal Distillation Techniques and Equipment/ U. S. Dept. Interior, Saline Water Conversion Program, Progress Rept. 12 (November 1956). 

The Office of Saline Water is directing a large number of investigations into the feasibility of new processes for producing fresh water starting with sea or brackish water as a source. It is desired that these plants last for 20 years or more. This paper points up ways in which the economic waste resulting from corrosion in saline water plants can be avoided. The article is based on a review of the corrosion literature and on consultations with marine experts in the field. Of the many materials for distillation plants, steel is the most important. It can be used to handle sea water below 250° F., if proper steps are taken such as the removal of all air (oxygen) from solution. For severe service and better performance metals like titanium, Hastelloy C, Monel, cupro-nickels, aluminum, aluminum brass, or Admiralty brass are used. 

Growing scarcity of fresh water in many places in this country and the rest of the world has stimulated the development of several potentially useful processes for saline water demineralization. Because fresh water is such a cheap commodity, these processes must demonstrate the maximum conceivable economy to compete with even the most expensive natural fresh water sources. Nearly all of these methods require considerable energy, either as heat or as electric power. Since this is a large cost item in these processes, solar distillation offers substantial operating economies, but at the expense of large investment requirement. 

The support and cooperation of the Office of Saline Water, U. S. Department of the Interior, in a solar distillation program, a portion of which is the subject of this paper, are gratefully acknowledged. 

Among the methods of saline water conversion being investigated by the Department of the Interior s Office of Saline Water is direct solar distillation. One phase of the study of solar distillation includes the field evaluation of stills of promising design, which is being carried out for the Office of Saline Water by Battelle Memorial Institute. 

Basically, the relative volatility of the components in sea water or saline waters is reversed by this type of ion exchange. Thus, the 3.5% of ordinarily nonvolatile salts present in sea water are made volatile by substituting for them a volatile salt such as one of the ammonium carbonates. This substitution puts distillation in an entirely different light The minor component is now to be distilled away from the major component, water, which should reduce the amount of distillation to be done per unit quantity of water produced by manyfold compared to distillation (or evaporation) processes in which all of the recovered water must be distilled. 

Hydrate Natural gas and condensate in distilled and saline water and in methanol Reference Tohidi et al. (1994a, 1995b, 1996b)... 

Bowles and Apte [698] have described a method for the determination of methylmercuiy compounds in non saline waters using steam distillation followed by gas chromatography with an atomic fluorescence spectrometric detector. These workers evaluated steam distillation as a technique for the separation of methylmercury compounds from water and obtained recoveries in spiking experiments ranging from approximately 100% in fresh waters and estuaries to 80% in sea water. 

Beryllium has been determined [764] in non saline waters and in sea water at oceanic levels of 2.30pM. Two ml of 0.1M EDTA, 2ml of 1.0M sodium acetate, 1.0ml of benzene and lOOpl of l,l,l-trifluoro-2-4-pentanedione were added sequentially to 150ml samples. Following liquid-liquid extraction using detailed handling procedures, the organic phase was mixed with 1.0ml of 1.0M sodium hydroxide (de-emulsifier), washed several times with distilled water and the resultant beryllium l,l,l-trifluoro-2,4-pentanedione complex analysed by gas chromatography with electron capture detection. 

The set of data in Table 6.4 was generated so that the concentration of dissolved ions increases from data set 1 to set 5, but the relative abundance of the ions is preserved (check it, for example, by comparing the Mg Ca ratio in data sets 1-5, Table 6.4). This imitates dilution of a saline water by different amounts of a fresh (ideally, distilled) water, a common occurrence in nature. The data of Table 6.4 have been plotted once with a linear concentration axis (Fig. 6.2) and once with a logarithmic concentration axis (Fig. 6.3). The outcome is striking the same data plotted with a different concentration axes reveal intrinsically different patterns. On the linear plot the lines of the individual water samples differ in their gradients, whereas on the semilogarithmic plot the lines have the same gradients. The latter well reflects the dilution of saline water with fresh water, whereas the former... 

An important factor in the interaction of foreign surfaces with blood is the rapid adsorption of plasma proteins onto such surfaces when they are exposed to blood (4). For this reason the adsorption of radioactively tagged blood components on heparinized and unheparinized surfaces was measured. Proteins were dissolved in approximate physiological concentrations in a buffered (pH 7.35) physiological saline solution and the solutions were exposed to the test surfaces for 2 hours at 37 °C. in a static system. After the exposure, the surfaces were rinsed with physiological saline and distilled water and then dried. The amount of protein on the surfaces was determined in a 27r-gas flow proportional counter (7). As shown in Table III, although both heparinized surfaces were nonthrombogenic, there is no consistent pattern of either increased or decreased adsorption of the proteins caused by the heparinization. In-... 

PAMCl solution needs to be prepared from the ampule containing 1 g of desiccated 2-PAMCl inject 3 ml of saline, 5% distilled or sterile water into ampule and shake well. Resulting solution is 3.3 ml of 300 mg ml ... 

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