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Seawater Desalination – Desalination Increases Salinity To Approximate Natural Change


Seawater Desalination - Desalination Increases Salinity To Approximate Natural Change

Introduction: Even under worst-case climate change scenarios, increased salinity from seawater desalination is nearly as high as changes in salinity from natural evaporation, new research finds. 

Slight Changes In Salinity 

New research finds that even under the worst-case scenario of climate change, the increase in salinity from desalination is well within the range of changes in salinity caused by natural evaporation. 

That’s what researchers at New York University’s (NYU) Abu Dhabi Arab Center for Climate and Environmental Sciences (ACCESS) and Water Research Center found. This is true even under the worst-case scenarios of climate change and projected desalination. 

The paper, “Effects of Arabian Gulf/Persian Gulf desalination on basin-scale long-term salinity,” was published in Scientific Reports. 

The bay is a naturally extreme marine system. We’ve been using a small fraction of the increased seawater in our waters for desalination.

New York University study found. Because marine life has adapted to high and variable natural salinity. Therefore, small changes in salinity are not expected to have an impact on the marine environment in the Gulf region. 

“The Gulf is a natural extreme marine system,” said John Burt, a joint chief researcher of the United Nations Water Research Center of New York University and the Arab Center for Climate and Environmental Sciences. 

Bert added: “The results of this study show that even under the worst climate forecast, the salinity increase and the trend of seawater desalination increase in the coming decades may have little impact on the salinity in the Gulf. And the organisms here have been exposed to the normal seasonal variation range of salinity.” 

Impact of expansion of seawater desalination

In order to meet the freshwater demand, many Gulf countries plan to improve the desalination capacity. The increasing seawater desalination activities may lead to more high-salinity water being released into the bay, and such actions can not determine the impact on the marine ecosystem of the bay. After the United Nations approved a paper entitled “Seawater Desalination and Brine Production Status: Global Outlook”, the issue of brine treatment and management once received attention. 

Saudi Arabia, the United Arab Emirates, Kuwait and Qatar are responsible for 55% of the global brine. 

The paper called brine “salty dilemma” and pointed out that the global desalination plants discharged 142 million m3/d of high concentration brine every day, an increase of 50% over the previous assessment. 

Saudi Arabia, the United Arab Emirates, Kuwait and Qatar are responsible for 55% of the global brine. 

The authors of the report from the Institute of Water, Environment and Health of the United Nations University (Canada), Wageningen University (Netherlands) and the Kwangju Institute of Science and Technology (South Korea) found that “the amount of discharged brine per cubic meter of clean water produced by factories in the Middle East is four times as much as that of the river water membrane treatment technology”. 

A key discovery in the latest research report of New York University is that any increase in salinity will force the flow through the Strait of Hormuz to increase accordingly, resulting in the rapid renewal of the Gulf waters. 

The conclusion is that even in extreme cases, the increase in salinity of the basin scale is not expected to exceed the level that will have a significant impact on marine organisms (such as animals and plants) in the bay. 

Moreover, with the increase of these salinity levels, the bay organisms have been exposed to the range of natural changes.

Reduce the impact of seawater desalination on the environment

A project in Spain is exploring how desalination plants will adjust their operation to further improve the energy required for desalination.

This cooperation, called LEAD (Leading Experimental Accelerator for Seawater Desalination), is being studied at 10 experimental stations in the No. 2 Seawater Desalination Plant in San Pedro Pinatar, Murcia, Spain.

This study will cover all stages of seawater desalination process, including sand filtration, air floatation-filtration, air floatation, ultrafiltration, nanofiltration, reverse osmosis and membrane distillation.