Why don’t we get our drinking water from the ocean by taking the salt out of seawater? With so much water around us, it seems like a simple solution, right? Well, it is actually possible through a process called desalination. However, there are several reasons why the process is not as easy as you might think. So, why are we not tapping into it more?
Kenyans in arid and semi-arid areas face the ongoing challenge of inadequate access to clean drinking water. Various solutions, such as drilling boreholes and harvesting rainwater, have been tried but have yet to solve the issue.
Why don’t we get our drinking water from the ocean by taking the salt out of seawater?
The process of removing salt from seawater is desalination. The common methods of removing salt from water are reverse osmosis and distillation. For reverse osmosis, you force seawater through a membrane by adding pressure. Afterwards, you will obtain salt-free water on one side while the saline water remains on the other.
For distillation, we heat saline water to produce water vapour, which then goes through condensation to produce fresh water. Without further ado, below are some of the main reasons why we don’t get our drinking water through the various desalination methods available.
1. Desalination of water is expensive and requires a lot of energy.
The process of removing salt from seawater is complex and energy-intensive. Desalination plants need constant energy to power their high-pressure systems, which means higher electricity bills and often reliance on fossil fuels. These costs make it difficult to afford large-scale desalination. It also limits its viability in areas with limited electricity access, especially in rural areas.
2. Environmental degradation.
Desalination causes environmental degradation through its toxic by-product, brine. It is highly concentrated saltwater waste, which is usually goes back into the ocean. Brine is harmful to marine life and can degrade local marine ecosystems unless treated.
Additionally, brine is usually warmer than the surrounding seawater. It causes water temperatures to rise once it is discharged. As a result, this leads to the death of marine life that is not adapted to warm water.
3. Availability of alternative sources of water
Alternative water sources, such as rainwater harvesting, groundwater extraction, and water recycling, are cheaper, so many people find them more convenient.
For instance, harvesting rainwater is a low-cost method that works well in areas with seasonal rains.
4. It causes climate pollution.
Desalination industries often use fossil fuels, which emit greenhouse gases. These gases contribute to global warming and pollute the climate.
Why can’t we separate salt from water?
Salt is sometimes difficult to remove from water because it dissolves easily and creates strong bonds that require great energy to break. This energy can be in great heat, such as in a distiller, or great pressure, as seen in reverse osmosis.
Can you filter ocean water to drink?
Trying to drink filtered ocean water without proper desalination can be quite harmful. Pure filtration can lead to retention of the high salt content found in ocean water, leading to severe dehydration. Ensure you use the specialised desalination processes before considering whether ocean water is safe for drinking.
Why can’t we extract salt from the ocean?
We can actually extract salt from seawater through evaporation. However, if the goal is to turn ocean water into drinkable fresh water, it requires more than just removing the salt. The full desalination process is very costly and requires a lot of energy.
Can salt be harvested from the ocean?
Yes, you can harvest salt from the ocean through solar evaporation or by boiling seawater over high heat to evaporate the liquid and leave the salt behind. However, solar evaporation may take longer as it uses no fuel or electricity.
Wrapping up
Why don’t we get our drinking water from the ocean by taking the salt out of seawater? As seen above, desalination is quite costly and may cause environmental degradation. However, with the advancement in technology, we may someday be able to tap into this water source more sustainably. Until then, it is advisable to use alternative drinking water sources like rainwater harvesting.
