x Abu Dhabi, UAESaturday 20 January 2018

Water you can drink, from a cow? Go on, pull the udder one

Farm recycles 300 cubic metres of animal affluent each day to meet about a quarter of its own water needs for plants and cooling its livestock.

Raid al Essa, the maintenance manager at Al Ain Farms, shows the waste water after recycling, left, and before, right.
Raid al Essa, the maintenance manager at Al Ain Farms, shows the waste water after recycling, left, and before, right.

AL AIN // Raid al Essa held up a bottle with contents so clear that it could pass for mineral water.

Then he showed a second bottle: the liquid inside was yellow, the pure liquid waste from the farm's 2,500 milking cows.

The farm has been recycling the 300 cubic metres of the effluent that the animals produce each day and turning it into clear, purified waste water for two years now.

The technology has been so successful that the company behind it is considering expanding it to other operations.

"We do not encourage people to drink it," said Mr al Essa, the maintenance manager of Al Ain Farms for Livestock Production, during a demonstration for the media. "But it is actually perfectly safe."

Half of the treated waste water is used in landscaping, while the other half is misted over the 10 large hangars where the cows are kept, keeping them cool.

While the farm still needs another 905 cubic metres of fresh water a day to function, the operation is an example of how treatment methods are becoming more inventive in a country increasingly aware of just how scarce its water is.

"This is a unique system," said Dr Ilham Kadri, the general manager for the Middle East and Africa at Dow Advanced Materials.

The company provided the technology behind the farm's Dh750,000 treatment plant, which was built and installed by another company, Veolia Water.

The system starts with a network of drains that collect the outflow from the hangars where the cows are kept. The liquid is then pumped to a tank 300 metres away. The treatment starts there, said Joy Vazhappilly,Veolia's customer services manager.

The liquid passes through two large filters to remove large particles, before entering an "ultra-filtration unit" that removes all particles larger than 0.03 microns.

"The average bacteria size is 0.2 microns," said Mr Vazhappilly, explaining that ultra-filtration effectively cleans most bacteria and viruses from the water.

After that, a process of reverse osmosis - commonly used in desalination plants - removes any dissolved chemical pollutants.

Once this last purification stage is completed, said Mr Vazhappilly, the end product exceeds municipal standards on water quality.

The cleaned water is cooled to a comfortable 27°C. Whenever the temperature passes this threshold, it is sprayed in the cow hangars. The mist helps keep the animals comfortable, even in the summer heat, said Mr al Essa.

Such projects make both environmental and economic sense, said Dr Kadri: "If you reuse your waste water, it is no longer a waste."