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Table of Contents
- 1 What is brackish water? Meaning and definition
- 2 Characteristics of brackish water: how does it differ from fresh water?
- 3 Is brackish water safe to drink? Can it be used for irrigation?
- 4 Industrial uses of brackish water
- 5 Why use brackish water in some industrial processes? Benefits and environmental challenges
Brackish waters have a salt concentration intermediate between fresh water and seawater.
Its chemical composition determines its quality for various purposes, from the from human consumption to applications in aquaculture, agriculture, energy generation and industrial processes.
Although these uses are very interesting, brackish waters also play an important ecological role, and require sustainable management that guarantees their long-term availability.
What is brackish water? Meaning and definition
The adjective "saline" defines water with a significant amount of dissolved salts in it, which directly affects:
- Its physical properties.
- Its ability to support different forms of aquatic life.
- Its consumption by humans.
From a geological point of view, brackish waters They are transition zones between fresh water and salt water of the sea.
Technically, brackish water is considered to be water that It contains between 0,5 and 30 grams of salt per liter (between 0,5 and 30 parts per thousand /ppt)Although its salinity may vary depending on its proximity to oceans, seas or salt lakes, the presence of minerals in the soil or the climatic conditions of the area.
Characteristics of brackish water: how does it differ from fresh water?
Brackish waters are located both in the land surface, As in underground aquifersand they always have an inflow of fresh or salt water (that is, which are not stagnant waters).
Some examples are coastal lagoons (coastal lagoons formed with seawater, but partially separated from it), estuaries (where fresh water and salt water mix), saline springs and endorheic basins (geographic depression where water accumulates).
In addition to their salinity, brackish waters are characterized by their temperature and turbidity.
The temperature of brackish water is usually higher than that of fresh water, which It affects its ability to retain oxygen. and, consequently, to some biological processes, such as the distribution of species.
Brackish waters also They tend to be turbid when compared to those of freshwater rivers or lakes.
This is due to the high presence of suspended particles, sediments and organic matter, which directly affects processes such as photosynthesis or oxygen production by aquatic plants.
In addition, brackish waters They usually have a higher concentration of sodium, potassium, calcium, magnesium, chloride, sulfate, bicarbonate, carbonate, and nitrate. than fresh water.
Is brackish water safe to drink? Can it be used for irrigation?
Brackish water has a pH similar to that of seawater, and its potability depends on its composition.
Basically, this means that when its salinity is high or it contains many minerals, it is considered unsuitable for human consumption.
To To make brackish water potable, it is necessary to desalinate it industrially through a reverse osmosis process (by passing the mass of water through filters and semipermeable membranes to remove the salt) or by electrodialysis (since water with a higher salt concentration has higher conductivity. A good option is to use electrical energy to separate the salts from the water).
Regarding the possibility of using brackish water in agriculture, something similar occurs: its amount of concentrated salt will determine its suitability for crop irrigation.
Industrial uses of brackish water
Although it is not recommended for directly watering vegetables or most fruits, Brackish water is used to irrigate salt-tolerant crops., such as cotton or some varieties of rice.
In aquaculture, it allows the controlled breeding of fish and shellfish species that tolerate salt water, such as shrimp, sturgeon, sea trout, or some varieties of salmon.
Other uses of brackish water include:
Solar thermal power plants
Solar thermal power plants are industrial facilities in which solar radiation is used to heat a fluid which, through a thermodynamic cycle, harnesses its power to move an alternator and generate electrical energy.
In these plants, the brackish water, when heated, produces large quantities of steam that drive the turbines to produce electricity
Brackish water It is also used for cooling equipment or cleaning solar panels.
Chemical industry
Thanks to its salinity, brackish water is used as a solvent and as a raw material in the manufacture of some chemical products.
Wastewater treatment
In their natural habitat, brackish waters act as a filter that traps sediments and nutrients coming from rivers.
This process It helps maintain water quality in the oceans.preventing the proliferation of harmful algae.
In some Treatment plants, Brackish water is used for wastewater treatment, considerably reducing the demand for drinking and fresh water for this purpose.
However, as salinity increases, the rate of degradation of organic matter in these waters decreases, requiring special measures such as adding a salinity regulating tank, increasing the clarifier retention time, or increasing the aeration volume.
Why use brackish water in some industrial processes? Benefits and environmental challenges
Brackish water is more abundant than fresh water, which is becoming increasingly limited and scarce.
Therefore, using saline water can be a sustainable alternative in certain sectors and activities, helping to reduce pressure on water resources.
Treating wastewater with brackish water also minimizes pollution and promotes people's health and safety.because the discharge of pollutants into freshwater areas is much lower.
Furthermore, brackish water allows for the expansion of economic and industrial activities to distant and remote regions, which is an advantage for many communities.
Are we therefore talking about a resource with potential for industry?
The industrial applications of brackish water are undeniable: Some sources indicate that desalinating and purifying brackish water using reverse osmosis uses half the energy required to desalinate seawater, while its use in agriculture in recent decades has boosted job creation and crop production in more arid areas.
However, Brackish waters have enormous ecological valueand they face challenges that threaten their health such as pollution, uncontrolled dumping of industrial, agricultural and urban waste, climate change or coastal development, which puts their ecosystems and the species that live in them at risk.
At SITRA we offer comprehensive services for water management in industry
We guarantee efficient solutions for water treatment and reuse, and We are committed to innovation and sustainability in all our projects.
