Saline water

Summary

_Salt water Saline water (more commonly known as salt water) is water that contains a high concentration of dissolved salts (mainly sodium chloride). On the United States Geological Survey (USGS) salinity scale, saline water is saltier than brackish water, but less salty than brine. The salt concentration is usually expressed in parts per thousand (permille, ‰) and parts per million (ppm). The USGS salinity scale defines three levels of saline water. The salt concentration in slightly saline water is 1,000 to 3,000 ppm (0.1–0.3%); in moderately saline water is 3,000 to 10,000 ppm (0.3–1%); and in highly saline water is 10,000 to 35,000 ppm (1–3.5%). Seawater has a salinity of roughly 35,000 ppm, equivalent to 35 grams of salt per one liter (or kilogram) of water. The saturation level is only nominally dependent on the temperature of the water. At one liter of water can dissolve about 357 grams of salt, a concentration of 26.3% w/w. At boiling () the amount that can be dissolved in one liter of water increases to about 391 grams, a concentration of 28.1% w/w. At , saturated sodium chloride brine is about 28% salt by weight. At , brine can only hold about 26% salt. At 20 °C one liter of water can dissolve about 357 grams of salt, a concentration of 26.3%. The thermal conductivity of seawater (3.5% dissolved salt by weight) is 0.6 W/mK at . The thermal conductivity decreases with increasing salinity and increases with increasing temperature. The salt content can be determined with a salinometer. Density ρ of brine at various concentrations and temperatures from can be approximated with a linear equation: where the values of an are: About four percent of hydrogen gas produced worldwide is created by electrolysis. The majority of this hydrogen produced through electrolysis is a side product in the production of chlorine.

Official source

https://en.wikipedia.org/wiki/Saline_water

About this result

This page is automatically generated and may contain information that is not correct, complete, up-to-date, or relevant to your search query. The same applies to every other page on this website. Please make sure to verify the information with EPFL's official sources.

Related publications (2)

Related concepts (15)

Related courses (1)

Related lectures (9)

Coastal reservoir contributes to alleviating the freshwater shortage in stressed areas, and the salinization of reservoir water is one of the most important challenges that coastal reservoir faced. Field-investigation indicates that there are many deep pools located at reservoir bed, and a large amount of high-salinity water was found within a deep pool which was hardly be desalted. Laboratory experiments and numerical simulations with different depth and locations of deep pools were conducted to further discuss the influence of deep pool on the salinization of reservoir and adjacent aquifer. Results showed that deep pool has greatly increased the salinity of reservoir water due to high-salinity water stored in the deep pool, which may act as an extra source of saltwater to the coastal reservoir during the dry season. The increasing depth of the deep pool was found to have negative impacts on the salinity of reservoir water, and as the distance from the deep pools to dam increased, the salinization extent in coastal reservoir decreased. Salinity data from the numerical simulations in coastal reservoirs and adjacent aquifer were matched the experimental data well. Flow field indicates that there is a high exchange capacity zone occurred from the deep pool to the seaward boundary, which gave the reasonable reasons for the existence of high-salinity water within deep pools. Those findings highlight the significant influence of deep pool on the salinization of the coastal reservoir, and explain the increased salinization by the deep pool.

2019

Mixing of fresh (river) water and salty water (seawater or saline brine) in a control fashion would produces an electrical energy known as salinity gradient energy (SGE). Two main conversion technologies of SGE are membrane-based processes; pressure retarded osmosis (PRO) and reverse electrodialysis (RED). In PRO, semipermeable membranes placed between the two streams of solutions allow the transport of water from low-pressure diluted solution to high-pressure concentrated solution. RED requires two alternating semipermeable membranes that allow the diffusion of the ions but not the flow of H2O. Lifetime and power density of the semipermeable membrane are two main factors affecting on deployment of PRO and RED. Semipermeable membranes with lifetime greater than 10 years and power density higher than 5 W/m(2) would lead to faster development of this conversion technology. An exergy analysis of an SGE system of sea-river can be applied to calculate the maximum potential power for electricity generation. Seawater is taken as reference environment (global dead state) for calculating the exergy of water since the seawater is the final reservoir. Once the fresh water is mixed with water of the sea or lake it becomes unuseful for human, agricultural or industrial uses loses all its exergy. Aqueous sodium chloride solution model is used in this study to calculate the thermodynamic properties of seawater. This model does not consider seawater as an ideal model and provides accurate thermodynamics properties of sodium chloride solution. As a case study, exergy calculation of Iran's Urmia Lake- GadarChay River system. The chemical exergy analysis considers sodium chloride (NaCl) as main salt in the water of Lake Urmia. The sodium chloride concentration is more than 200 g/L in recent years. Based on the exergy results the potential power of this system is 329 MW. This results indicates a high potential for constructing power plant for salinity gradient energy conversion.

Amer Soc Mechanical Engineers2016