November 30, 2023
Dubai’s expensive water world – The New York Times

Dubai’s expensive water world – The New York Times

For a desert city, Dubai looks like a water wonderland. Visitors can splash in the world’s deepest pool or ski in a mega mall where penguins play in the freshly made snow. A fountain – said to be the largest in the world – sprays more than 22,000 gallons of water into the air, synchronized with music from surrounding speakers.

But to maintain its opulence, the city depends on fresh water that it does not have. So it turns to the sea, using energy-intensive desalination technologies to help hydrate a fast-growing metropolis.

All of this has a cost. Experts say Dubai’s dependence on desalination is harming the Persian Gulf, producing a brackish waste known as brine that, along with chemicals used during the desalination process, increases salinity in the Gulf. It also increases the temperature of coastal waters and harms biodiversity, fisheries and coastal communities.

The Gulf is also under pressure from climate change and efforts to build Dubai’s multibillion-dollar islands through land reclamation. Beachfront real estate on offer includes a $34 million seahorse-shaped private island nestled in the man-made archipelago.

If immediate action is not taken to combat the damage, desalination, in combination with climate change, will increase the temperature of Gulf coastal waters by at least five degrees Fahrenheit across more than 50 percent of the area by 2050, according to a 2021 study published in the Marine Pollution Bulletin on ScienceDirect, a website for peer-reviewed articles.

Dubai, the most populous city in the United Arab Emirates, has taken steps to address the damage through environmental initiatives and new technologies, but pressure is mounting to do more. Later this month, the city will host the United Nations global climate summit, known as COP28, an idea that has already provoked tensions due to investments in fossil fuels by the UAE and other participating countries.

In addition to powering Dubai’s eye-catching recreational features, water is essential to sustaining life and desalination provides a thirsty city with clean drinking water. Dubai Electricity and Water Authority supplies water to more than 3.6 million residents, along with the city’s active daytime population of more than 4.7 million visitors, according to a 2022 sustainability report. By 2040 , the company expects these numbers to grow, increasing demand for drinking water.

The city desalined approximately 163.6 billion gallons of water last year, according to the sustainability report. For every gallon of desalinated water produced in the Gulf, an average of one and a half gallons of brine is released into the ocean.

In Dubai, the Jebel Ali Energy and Desalination Complex — the largest facility of its kind in the world — channels seawater, sending it through a series of treatment stages, and then to the city as drinking water. But Jebel Ali’s 43 desalination plants are powered by fossil fuels. The UAE produced more than 200 million tonnes of carbon in 2022, one of the highest per capita emissions worldwide.

Seawater desalination has been a lifeline in the UAE for nearly 50 years, but other coastal regions, such as Carlsbad, California, have recently adopted the technology in the face of severe drought. Florida is a national leader in desalination, and further inland, Arizona is considering piping desalinated water from Mexico.

Desalination efforts have also long been used in other Gulf countries, including Bahrain, Kuwait, Saudi Arabia and Qatar. Unlike its oil-rich neighbors, Dubai has an economy based primarily on tourism, real estate and aviation, although its brief oil boom of the 1960s and 1970s provided the financial basis for infrastructure of architectural grandeur. of the city.

“It’s a brand,” said Khaled Alawadi, associate professor of sustainable urbanism at Khalifa University in Abu Dhabi. “Any tourist destination, especially if it has potential competition from the region, likes to dominate.”

At Deep Dive Dubai, the equivalent of six Olympic-size swimming pools of water fills an underwater city shaped like a giant oyster, inspired by the emirate’s pearl diving heritage.

The Burj Khalifa, the world’s tallest building, developed by Emaar and designed by Adrian Smith, uses an average of 250,000 gallons of water daily and requires a maximum cooling capacity equivalent to around 10,000 tons of melted ice. At the foot of the building, the 30-acre Burj Lake and its five dancing fountains use a Hitachi wastewater recovery system that reuses sewage water from the Burj Khalifa to replace the fountain water lost every day.

The construction of Dubai’s artificial islands also puts a strain on the Gulf’s water resources. A study found that the average water temperature around the Palm Jumeirah island, designed by HHCP Architects, increased by about 13 degrees over 19 years. Another study cited land reclamation, along with brine and industrial waste, as the cause of excessive growth of microscopic algae in the Persian Gulf, known as algal blooms or red tides. Some of these harmful blooms have forced desalination plants to reduce or close operations.

“Development near water is much more preferable than development in the desert landscape, and you are increasing the coastline,” said Dr.

State-owned utility Mr. Smith and HHCP Architects declined to comment for this article.

Dubai has announced environmental initiatives to tackle its enormous resource consumption, including a drive to reduce energy and water demand by 30 percent by 2030 and obtain 100 percent of its power generation from renewable energy sources ​​by 2050. The country has even turned to the sky as an alternative source of water, hiring scientists to chemically stimulate clouds to produce rain (although there is little agreement that this process actually works) and encouraging hotels in Dubai to produce their own water through atmospheric collection.

Faisal al-Marzooqi, an associate professor at Khalifa University who researches water desalination in the UAE, said he has pressured government officials to prevent facilities from using drinking water for functions that do not involve human consumption, such as metal fabrication facilities and water parks. .

“At a time when water is really valuable, there could be better ways to do things like recreational activities,” he said.

He added that rising salinity levels in the Gulf were dangerous because the water was already hypersaline and adding more salt threatened the Gulf’s biodiversity.

The global salinity of seawater is typically 3.5 to 4.5 percent; the Persian Gulf reaches the latter end, making it more vulnerable to brine. About 70% of the Gulf’s coral reefs have disappeared, with 21 coral-dependent fish species at high risk of extinction. These changes have resulted in a regional loss of $94 billion per year to tourism, aquaculture and fisheries, according to a study published in 2021 in the Marine Pollution Bulletin, an academic journal.

“This is a really big problem,” said Dr. al-Marzooqi.

The region’s seagrass meadows and mangroves are also facing difficulties. These ecosystems are important growing areas for commercially valuable species such as pearl oysters; they also help stabilize wave rhythms and erosive forces and can absorb large amounts of greenhouse gases from the atmosphere. Its decline has contributed to an oceanic desert devoid of the usual biodiversity found in the Arabian Sea and Persian Gulf – the world’s largest so-called dead zone.

Since the 1970s, dead zones have proliferated around the world and include one in the Baltic Sea, three times the area of ​​Maryland.

“We have ours in the Gulf of Mexico, where all the water that goes down the Mississippi is deoxygenated and everything dies,” said Bruce Logan, director of the Energy and Environmental Institute at Pennsylvania State University.

But Dubai is making progress. In 2021, the city required that all new desalination projects be built using what is widely considered the most efficient and environmentally friendly desalination technology available: reverse osmosis. Most of the country’s desalination plants, however, still use an older technology called multistage flash distillation.

Unlike reverse osmosis, which removes salt and other contaminants by pushing water through a semipermeable membrane, multistage flash distillation relies on heat. Decades ago, when the UAE began exploring desalination, the technology could better deal with the Gulf’s high salinity, although reverse osmosis can now do the same. And while both technologies create brine, the byproduct of multi-stage flash distillation is much hotter, further disrupting the ecosystem.

The utility’s new Hassyan Power Plant in Dubai will use reverse osmosis desalination and has operated for more than a year on natural gas instead of coal. The $3.4 billion project is expected to generate more than 140 million gallons of water per day.

The utility has begun researching sustainable options for managing and recycling brine using Zero Liquid Discharge and membrane distillation, technologies that experts hope will treat saline water and wastewater. However, techniques that address the problem at scale have not yet been applied, although solutions are being researched around the world.

Despite efforts, Dubai faces criticism. “To be honest, I don’t see many initiatives,” said Dr. al-Marzooqi. “I feel like the focus is more on the renewable energy that powers the systems, but there’s almost no talk about brine.”

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