To quench the thirst of the UAE, the equivalent of four billion bottles of water is desalinated every day.
The demand for water is continually increasing due to population and industry growth coupled with the demand for a certain standard of living, which will see even more desalination plants being built in the future.
Notably the biggest plant in the world, the Jebel Ali Phase 2 plant, with an annual production of 300 million cubic metres, is currently in the making.
In his research paper The Effect of Water Scarcity on the Future Growth in the Desalination Industry in GCC Countries published in 2002, Mohammad Dawood, acting manager of Water Resources Management at the Environment Agency – Abu Dhabi predicted that by 2025, annual production of desalinated water would be 4325 million cubic metres. Today production is estimated at 4380 million cubic metres.
Desalination plants dotting the coast line from Dubai to Kuwait are legally flushing brine, or waste water, carrying chlorine and metals into the Arabian Gulf by the tonne every day. Antiscalants to reduce scale formation in desalination plants can produce increased and harmful algae growth when pumped back to the ocean and recent links to devastating red tide have been made between the industry and the marine environment. Brine's increased salinity can reduce vitality and biodiversity while chlorine is very toxic for many organisms in the mixing zone - an area where effluents are diluted before flushing.
Research shows that the Gulf may act as a sink with the risk of long-term accumulation of substances like copper which do not degrade and get transported with sediments.
Traditionally desalination plants dilute effluents in a "mixing zone" but as the region lacks frequent rainfall and surface runoff to refresh the Gulf, dilution is limited, said Dawood. The Gulf has salinity levels of 45,000 parts per million (ppm) compared to open oceans which typically have 35,000ppm. Near desalination plants salinity is around 50,000ppm according to Dawood.
Sabine Lattemann, a researcher from the Institute for Chemistry and Biology of the Marine Environment (ICBM) at the University of Oldenburg in Germany has identified 45 Multi Stage Flash (MSF) plants, 32 Multi Effect Desalination (MED) plants, and 41 Reverse Osmosis (RO) plants in the Gulf.
Lattemann's research shows the Gulf has mainly large MSF distillation plants that discharge a waste water flow of more than 1,000 cubic metres per second which has a higher temperature and increased salinity, including chlorine and antiscalants, as well as corrosion products such as copper.
John Burt, Assistant Professor, Department of Natural Science and Public Health, Zayed University said engineering solutions can be used to diffuse the discharge from desalination facilities to lessen their impacts, but on certain conditions.
"In such situations it will be important to closely model and monitor the movement of water in the areas surrounding the discharge. Natural and man-made impediments to flow - such as points, islands, breakwaters, and jetties - may create retentive eddies, creating areas with limited flushing. Factors such as these will need to be monitored closely in designing desalination facilities so that ecological impacts are minimized," he said.
