How Can Salt Water Be Converted Into Drinking Water Through Desalination?

If the world faces a shortage of fresh water, it is likely that you will learn how to extract salt from saline water.

What is Salt Water?

Saltwater is water that has a considerable quantity of dissolved salt. We typically measure its salt saturation in “parts per thousand” or ppt. As an illustration, seawater has an approximate salt concentration of 35 ppt, indicating that there are roughly 35 grams of salt per liter (or kilogram) of seawater.

Different levels of dissolved salt concentration determine the classification of water types, such as freshwater, brackish water, saline water, and briny water.

Water Type	Salt Concentration
Fresh Water	0-0.05 ppt (< 0.05%)
Brackish Water	0.05-30 ppt (0.05–3%)
Saline Water	30-50 ppt (3–5%)
Briny Water	>50 ppt (> 5% up to 26%-28% max)

Edible water must maintain a saline concentration below 0.05 ppt in order to ensure good-quality drinking water. The lower the level of salt, the better the quality of the water for consumption. Ideally, drinking water should have a salt concentration of zero. When it comes to agricultural irrigation, the salt solution should be limited to less than 2 ppt. This is because higher amounts of salt can lead to soil salinization and result in agricultural losses. It is not just plants that suffer, but humans as well, as they cannot afford the consequences of consuming highly saline water. Natural seawater, for instance, can actually increase our thirst instead of quenching it, eventually leading to dangerous dehydration. The high concentration of salt in seawater takes water away from our bodies instead of hydrating us. In severe cases, this can even lead to renal failure.

More Fresh Water is Needed

The main focus of this article is to provide an introduction to the process of converting saltwater into drinkable water. However, it is crucial to address an important matter before proceeding, namely, the availability of the water, which is currently at a critical stage and may not be sufficient to meet the growing demand.

Only a small fraction, specifically 3%, of the Earth's water is freshwater. Out of this limited supply, only a mere 1.2% is suitable for human consumption, while the remaining portion remains trapped in frozen forms such as glaciers, ice caps, and permafrost, or hidden deep within the Earth's crust. In stark contrast, seawater makes up a significant 97% of the planet's water resources. If we can discover a means to effectively harness and utilize this abundant seawater, it could play a pivotal role in resolving the impending global water crisis.

According to the World Health Organization (WHO), around the globe, about one billion people are facing persistent water scarcity throughout the year. It is projected that by 2025, nearly half of the world's population will not have access to sufficient freshwater resources.

Other factors also compel us to search for freshwater sources. An evident issue arises from industrial pollution in proximity to rivers and water bodies, posing a significant threat to the safety of our current drinking water supply. Additionally, the escalating effects of global warming have led to rising sea levels, resulting in the intrusion of saltwater into freshwater ecosystems. Consequently, the mounting salinity levels in water render freshwater unfit for consumption.

Convert Salt Water into Fresh Water

1. Reverse Osmosis: Most desalination plants rely on reverse osmosis as the main technology for purifying water. This method uses a semipermeable membrane to separate salt molecules from water molecules, allowing only the latter to pass through. IDE Technologies, known as the leading company in Israel, possesses cutting-edge reverse osmosis technology. They own three major desalination plants, which collectively produce around 1.5 million cubic meters of fresh water. This output is roughly half of the freshwater supply in the entire country. However, the high cost of desalination technologies and equipment renders them accessible only to large water plants.
2. Solar Still: The solar still method utilizes solar heat as an energy source to facilitate a distillation process, resulting in the formation of dew on surfaces such as plastic sheets. Whenever necessary, individuals can easily carry out this method.

• Dig a hole and place a container at its base.
• Locate a plastic sheet and use heavy stones to secure its edges, ensuring that it completely covers the pit. Then carefully position a lighter item in the center of the sheet to weigh it down slightly. It is important that this sink area aligns directly over the bowl.
• Allow the “water collecting device” to remain undisturbed overnight. When you check on it the following morning, you will observe that water has accumulated in the bowl.

Water Distillation

Water distillation involves the use of containers and the application of heat to bring water to a boiling point. This particular technique is ideally suited for individual purposes as well.

1. Place the empty glass upside down in the pot, ensuring its mouth is facing upward. 
2. Carefully pour seawater into the pot, taking care not to splash any water into the glass.
3. Invert the lid, positioning its lowest point directly above the glass.
4. Light a fire underneath the pot and allow the water to boil, observing as the vapor gradually condenses and drips into the glass.

Transfer Fresh Water into Drinking Water

Now that you've mastered the art of producing salt-free water, we want to equip you with the knowledge of transforming freshwater into safe drinking water right in the comfort of your own home. If you reside in an area blessed with an abundance of freshwater, count yourself fortunate as you are more privileged than approximately one billion individuals worldwide. However, it's crucial to acknowledge that even freshwater can be subjected to various impurities that compromise its quality. The primary culprits include mineral substances, chemicals originating from nearby industrial operations that seep into water sources, pesticide residues lingering on plants, pollutants carried through run-offs during rainfall, and more.

For households, the optimal and budget-friendly approach is to utilize a water filtration system. By employing a tap water filter, harmful metals and sediments are removed, resulting in cleaner water. Additionally, a refrigerator water filter ensures that refreshing and healthy drinking water is available at all times. Moreover, an under-sink water filtration system guarantees that the water entering your cup is safe for your family's consumption. Filter1pro.com is a reputable online store specializing in drinking water filters, offering reliable products of comparable quality to those of the original equipment manufacturer (OEM) yet at affordable prices.