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Plants that transform seawater into freshwater produce lots of polluting waste

Desalination factory Credits : National Center of Excellence Desalination, Australia

Many countries which don’t have the means to produce fresh water are turning towards desalination sea water plants that transform seawater into freshwater.  However is this solution risk free?  A recent study has warned that billions of tonnes of waste are thrown into the sea from these plants which could have the potential to be recycled. 

A study published by the Institute of Water, Environment and Health at the University of United Nations (Japan) in the journal Science of the Total Environment revealed that desalination plants produce lots of brine – a salted by-product that is loaded with chemicals.  For each litre of fresh water produced 1.5 litres of brine is created.  This is the equivalent of 142 billion squared metres of brine produced per day (50% more than was previously estimated).  This waste is simply abandoned which threatens marine life despite the fact the by-product could be recycled.

Food chain is threatened

The study’s authors warn that the majority of this waste ends up in our oceans.  The high concentrations of salt, as well as the copper and chlorine products which are incorporated, can harm marine organisms.  “Brine underflows deplete dissolved oxygen in the receiving waters,” explained Edward Jones from the University of Wageningen in the Netherlands and co-author of the study. “High salinity and reduced dissolved oxygen levels can have profound impacts on benthic organisms, which can translate into ecological effects observable throughout the food chain.”

sel usine dessalement
Why can’t you transform the waste into table salt ? Credits : Pixabay

Recycling solution

However researchers believe that this by-product could be recycled instead of being unnecessarily wasted.  For example, according to researchers we could use this salted water to irrigate cultures which can tolerated this mixture, use it for fish farming, produce electricity or even as table salt.  We could even recuperate the chemical products and then reuse them elsewhere.

There are about 16, 000 plants producing tonnes of waste everyday, particularly in the Saudi Arabia, United Arab Emirates and Qatar.  The number of plants should increase in the next few years considering the high demand for fresh water.  What’s more the technique for making freshwater from seawater is increasingly more affordable. It should therefore be a priority that solutions are found to recycle this waste.


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