This new desalination device, made with 170,000 recycled plastic bottlespowered by mechanical wave energy as it floats in the ocean, creating up to 53,000 liters of fresh water per day, while discharging far less concentrated brine than other designs.
Only 3% of the Earth’s water is fresh water; if we remove the water from the glaciers, only 1% remains. Humanity therefore finds itself on the wettest planet in the solar system, surrounded by water, and yet facing critical shortages of fresh water that already affect half of the world’s population.
As the effects of climate change continue to progress and the world’s population grows to an expected peak of around 11 billion people by the end of this century, water scarcity will worsen and the technology of desalination will become increasingly critical and pervasive.
The scalability of current desalination methods poses significant challenges. First, it will require huge amounts of energy as it grows, and this during the difficult transition from dirty energy to clean energy, when energy will be at a premium. Second, land-based industrial desalination plants require huge amounts of salt water, then extract most of the water and pump highly concentrated salt brine into the ocean, often contaminated with chemicals used to pre-treat the water. water and keep equipment clean. These heavy, salty discharges tend to sink to the sea floor, where they can cause serious ecological damage.
But there’s no getting around it; mankind will need more and more desalination plants in the future. For it, Oneka’s wave-powered floating desalination buoys could be a valuable breakthrough.
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sustainable system.
For starters, they’re mostly constructed from recycled plastic bottles; each “Iceberg” class buoy represents more than 170,000 bottles that will no longer end up in landfills or join their people on the Great Pacific Garbage Island.
They are 100% powered by wave energy.
Anchored to the seabed anywhere with an average wave height of more than 1m, they absorb the energy of passing waves and convert it into pumping mechanical forces that pull seawater up and push it up. about a quarter through a reverse osmosis desalination system to create fresh water. , drinking water, which is pumped to land through high-density polyethylene pipes, again using only wave energy.
The remaining three-quarters are mixed with brackish waste from the desalination process and returned to the sea.
The brine is only 30% saltier than the water around it, a negligible change from the much more concentrated brine released by shore-based desalination plants, and since these buoys are usually anchored at least one mile (1.6 km) offshore, in large assemblages with plenty of space between units, the brine disperses well and toxic ecological effects are minimized.
Oneka says that in their own tests they have shown that within a radius of about 3m from each device there is no appreciable increase in water salinity compared to the baseline.
To minimize the risk of sucking in fish, eggs or other small aquatic organisms, fine mesh filters protect the inlets and the pump cycle includes backwashing.
The Iceberg class units are designed to generate between 30 and 50 m3 of water per day, sufficient for the daily needs of 100 to 1,500 people, depending on lifestyle and consumption.
On-board sensors, powered by small photovoltaic solar panels, constantly monitor the water produced, ensuring the proper functioning of the equipment. Oneka offers post-processes to adjust the taste of water or adapt it to the needs of agricultural users.
They also require some maintenance: between three and seven visits per year to each unit for preventive and general maintenance. But once it’s settled, each unit is designed to operate between 15 and 20 years of service.
These devices are not similar to those of the largest land-based desalination plants. In fact, it would take more than 20,000 iceberg-class buoys operating at full capacity to match the production of clean water from the world’s largest desalination facility, the Ras Al-Khair Desalination Power Plant in Saudi Arabia.
Oneka says she is working on “utility scale appliancesfor areas that need larger amounts of water. These machines”Glacier classAccording to Just Have a Think, they will produce about 10 times more than the Iceberg, and according to Saltwire, they will be available in 2023 and demonstration tests will begin on the coast of Barrington, a community of 4,000 in Nova Scotia (Canada). ).
However, when adapted to local needs, existing machines seem to offer a cheap, scalable and reliable way to generate clean water without carbon dioxide emissions, without the need for coastal land space. It’s awesome technology, and we can think of a few better ways to reuse a few hundred thousand old plastic bottles.
More information: www.onekawater.com
