Egypt is pushing forward with desalination to meet potable water needs. What’s the environmental price tag? In 2020, Egypt announced a plan to invest more than EGP 134.2 bn in seawater desalination plants that would give us 6.4 mn cubic meters per day (cbm / d) of freshwater. With increased pressure on water resources — particularly with the building of the Grand Ethiopian Renaissance Dam — an increased reliance on desalination plants is “the most feasible solution” to meet our water demands, according to a paper published in the Ain Shams Engineering Journal (pdf). However, desalination comes at an environmental cost as a result of energy consumption and the production and disposal of brine.

How much water do we need? Egypt grapples with an annual water deficit of roughly 7 bn cbm, and it could be water scarce by 2025, according to a recent UNICEF report (pdf). The country is currently looking to increase its water capacity by 8.85 mn cbm / d of water by 2050 to improve its water security.

Where do things stand with our desalination plans? The desalination plan spans six five-year phases, the first of which is expected to see the government investing EGP 45 bn to build 47 seawater desalination pl ants. The first 21 plants in the project are expected to produce around 3.3 mn cbm/d of water.

The private sector is getting in on the action: The Sovereign Fund of Egypt (SFE) prequalified 17 consortiums for renewables-powered desalination projects earlier this year, including Hassan Allam, Engie, Orascom Construction, and Acwa Power, among others. It plans to have three or four of these plants tendered by 3Q 2023 and the remaining plants in the program’s first phase should be signed in the next 18-24 months.

We’re not the only ones relying more on desalination: Gulf countries mostly rely on desalination to meet their water needs, accounting for c.60% of the world’s water desalination capacity, according to Arab Center Washington DC. Saudi Arabia is responsible for about one-fifth of the desalinated water produced in the world and relies on desalination for about 50% of its potable water needs. In 2020, the country announced an investment of around USD 80 bn in desalination over the next decade. It is expected to have a desalination capacity of 8.5 mn cbm / d of water by 2050, Construction Week reported.

SOUND SMART- How to separate H2O and NaCl: There are two main types of desalination processes: Thermal and membrane desalination. Thermal desalination — including multi-effect distillation (MED) and multi-stage flash distillation (MSF) — uses heat to evaporate seawater, leaving behind the salt. The water vapor is then condensed back into liquid water, according to the International Renewable Energy Agency (IRENA) (pdf). This process is energy-intensive, but it can produce large amounts of fresh water. Meanwhile, membrane desalination, including electrodialysis (ED), and reverse osmosis (RO), uses semi-permeable membranes to filter salt from seawater. The membranes allow water molecules to pass through, but block salt molecules. This process is less energy-intensive and it can only produce smaller amounts of fresh water. RO plants are the dominant method for desalinating water in Egypt.

One big problem with desalination: What happens to the brine? In addition to greenhouse gas emissions, the production of brine is a significant environmental concern with desalination, according to the Marine Pollution Bulletin (pdf). Brine is a highly concentrated salt solution that is a waste product of the desalination process, according to the UN Environmental Program.

The majority of Egypt’s desalination plants are situated in coastal areas along the Red Sea and the Mediterranean Sea, Cairo University Geology and Water Resources professor Abbas Sharaky told Enterprise. Most of the brine produced by these plants is released back into the sea, which poses a potential danger to local marine ecosystems, he added.

Untreated brine can harm ecosystems: Brine’s high salt levels depletes oxygen and causes changes in water temperature and salinity, which can kill fish, coral reefs and other marine organisms, explains Assistant Director of the United Nations University Institute for Water, Environment, and Health Manzoor Qadir. Brine that is improperly treated and disposed of can also damage soil flora that play an essential role in the health of the soil and the environment, which can lead to nutrient deficiencies in crops and reduce the yields and quality, head of the Egyptian Association for Sustainable Development, Othman ElShaikh, told Enterprise.

How should brine be handled? The two methods desalination companies most commonly use to dispose of brine are surface water discharge or deep well injection, DesalEgypt Chief Commercial Officer Kareem Fanous told Enterprise. Surface water discharge is used when the feed water for the desalination plant is taken directly from the ocean, in which case the brine is diluted with seawater to reduce its salinity before it is discharged back into the sea. This helps to minimize the impact of the brine on the marine environment, he added. Deep well injection is used when the feed water for the desalination plant is taken from underground wells. The brine is injected into deep wells into the ground, which helps to isolate the brine from the environment and prevent it from contaminating groundwater, he noted.

Then there’s the energy consumption: Desalination is a very energy-intensive process and is typically reliant on fossil fuels for power. Plants in Egypt rely on electricity from the national grid that is generated primarily from burning natural gas, Sharaky said. Energy resources account for about 50% of the total production cost of desalination, Sharaky told us. However, there are signs of a shift towards renewables in desalination, with KarmSolar launching the country’sfirst solar-powered water desalination plant in Marsa Alam in May.

The saltier the water, the more energy-intensive the process gets: Salinity is correlated to power consumption — desalinating sea water (32k-45k parts per mn (ppm)) requires more energy than desalinating brackish water (2k-15k ppm) or Nile water (150-250 ppm), Fanous said. Power consumption is also based on the type of desalination technology used.

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