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Desalination as an alternative to water crises

Desalination as an alternative to water crises

By 2030, demand will exceed supply by 40 percent, experts predict. It is urgent to implement desalination techniques as an alternative to water crises.

Seas and oceans make up more than 97 percent of the planet's water resources, and half of the world's population lives no more than 63 kilometers from one water source, and yet we suffer from one water crisis after another.

Frustration is increased by the fact that there are currently solutions capable of improving our problems related to this resource.

From severe water shortages in South African Cape Town, where existing reserves last only 90 days, to well-documented problems in the city of Flint, in the US state of Michigan, where the outdated distribution system distributed water with lead to the population, it is clear that measures must be taken to guarantee the current supply of drinking water, not only for drinking, but to preserve the social fabric.

We depend on clean water to produce food, electricity, cars, clothing, and a variety of other things that are difficult to live without.

In fact, even without counting irrigation, less than five percent of purified water is used for consumption, most of the supply is used for washing, flushing and in industry.

For centuries, peoples prayed for rain and to collect water, but that is no longer an option. It simply is not enough. And on top of that, the rain is unpredictable, there may or may not be. But with the limitless supply of water in the ocean, there is a viable option: desalination.

In the 18th century, ships had their own desalination plants to ensure the supply of fresh water offshore. Then the seawater was boiled and then condensed. The resulting liquid had almost no salt, and the resulting brine was removed.

The advancement of reverse osmosis technology in the 1960s made this way of purifying water more readily available.

Today, more than 18,000 desalination plants operate in 150 countries, and the process requires 80 percent less energy than it did 20 years ago.

According to the International Water Association, the energy required to produce the volume of liquid that a household will consume in a year from salt water is less than that consumed by the family's refrigerator.

We also have to analyze the distribution systems.

As became apparent in Flint, most underground plumbing systems are in poor condition and can generate contamination from lead and other toxins.

Disinfectants are used to control the growth of bacteria, but they also pose a health concern, raise the risk of cancer, and make water taste bad.

Conventional wisdom would indicate that we need to fix the infrastructure, but there is another option: point of use (PDU) purification.

As typically only five percent of the water in the distribution system is used for drinking, it is much more efficient to use filtration at the PDU to purify the water at the point of use.

Additionally, filtration at the PDU is much more environmentally friendly than distribution of purified water, from the plastic used in the drums to the greenhouse gas emissions from the supplier trucks, the point of use eliminates those issues and purifies only what it takes, when it is needed.

Finally, we must still emphasize conserving and using water supplies more consciously and efficiently.

But only with conservation and reuse will not prevent water crises in the world. Desalination and point-of-use systems should complement conservation.

With the technology available today, there should never be a shortage of water, particularly when the industry can work in partnership with local, state and federal governments to help provide safe water.

As an example, the mining industry is a key economic promoter in South America and relies heavily on clean water to operate the mines.

Population and industrial growth added greater pressure to the natural supply of clean water, leading to a shortage that pitted industries, governments and citizens against each other.

In Chile, instead of adding pressure on the limited resource, the Caserones mining company opted to bring desalinated seawater to its mine, in addition to offering it to the local population of Caldera, allowing it to create a crucial resource for the community.

As a society, our goal should be for every human being to have access to the vital fluid. It is no longer sustainable, from an environmental, social or civil point of view, for the industry to depend on municipalities to cover its water needs.

The diversification of our water supply is necessary to bring unlimited water from the oceans and seas to our tables and businesses, and guarantee fresh water for all.

Translation: Veronica Firm

By Doug Brown

Video: Investing in the Worlds Water Crisis. John Collier (October 2020).