PLASTIC WASTE FACES THE FINAL CURTAIN
▶ Dubai company is making world’s largest barrier to collect discarded plastics from the sea, writes Daniel Bardsley
A UAE company is playing a central role in the battle to remove plastic waste from our oceans by making the world’s largest floating barrier to scoop it up.
Ecocoast, which is based in Dubai and has a factory in Umm Al Quwain, has designed and is making a strong but incredibly flexible screen, 550 metres long and 3 metres deep, to catch and contain debris.
But the problem of plastic is huge, and growing fast. From carrier bags to coffee cup lids, from children’s toys to packaging, plastic has become a part of almost every aspect of human life.
A study published recently in the journal Scientific Reports, written by researchers linked to the Dutch organisation Ocean Cleanup and universities, indicated that the Great Pacific Garbage Patch contains 1.8 trillion pieces of plastic – together weighing 80,000 tonnes.
The organisation came up with the estimate after surveys using boats and planes.
Ocean Cleanup, set up five years ago by Boyan Slat, 18, of The Netherlands, now employs 70 staff. It plans to send the world’s largest floating barrier to collect much of the waste.
And that is where Ecocoast’s expertise comes into play.
“This is completely unique – it’s something we developed specifically for this application,” said Australian Lachlan Jackson, managing director of Ecocoast.
“It’s one of the most challenging projects we have worked on because the manufacturing process is very complicated and detailed. Nothing on this scale has been done before.
“Reducing the amount of plastic that enters the waterways, the majority of which comes from the 10 largest rivers, is the most effective way to prevent further damage. But there’s damage that’s already occurred. I believe an engineering solution to clean up the pollution is required. I don’t believe a single-case approach would be the best way.”
Ecocoast, which was founded in 2009 and has about 90 staff, designs and produces marine barriers such as silt curtains, used to contain silt from dredging. The barrier it has designed and is making for the Ocean Cleanup is quite different.
It will have to cope with waves that, in the Pacific Ocean, can be more than 10 metres in height. It will also need to deal with constant stress from the tidal movement of the water.
The barrier consists of a grid of abrasion-resistant polyester panels separated by horizontal and vertical tension bands, which make the panels more rigid.
In the areas most at risk of wear and tear, the curtain is up to eight layers thick. It hangs beneath a separately produced 1.2-metre diameter, high-density polythene pipe that provides buoyancy.
“It needs to be incredibly strong and flexible,” Mr Jackson said. “The flexibility was the most challenging thing because it’s over 550 metres long. It needs to be very flexible for the different wave heights.
“And it’s designed to be out there for more than a year, so durability from ultraviolet light and marine environments is important.”
The screen weighs more than 5 tonnes and ballast weights of 24 tonnes are attached to keep it vertical. A flotation device supplied by Ocean Cleanup adds more than 150 tonnes, bringing the total weight to more than 185 tonnes.
The first 120m section of the curtain has now been shipped to the US.
Tests will continue on the curtain and its parts until the full system, which will be assembled at the Ocean Cleanup’s yard in San Francisco, is put to work in June or July.
“In terms of the testing, we’re going through a fairly diligent process,” Mr Jackson said.
“Ambitious is probably an understatement. Working with them is absolutely great. They’re an NGO and they’re very passionate about what they do. They all really believe in the cause.”
The Ocean Cleanup hopes to remove half of the plastic in the Great Pacific Garbage Patch within five years, with the material collected to be taken back to land for recycling.
Meanwhile, researchers in the US and Britain have engineered an enzyme that can digest some forms of plastic and may eventually help solve the growing problem of plastic pollution, a study said yesterday.
The international team of researchers tweaked the enzyme, and found they had inadvertently made the molecule even better at breaking down the plastic used for soft drink bottles.
“What actually turned out was we improved the enzyme, which was a bit of a shock,” said Prof John McGeehan, at the University of Portsmouth, UK, who led the research.
It’s one of the most challenging projects we have worked on. Nothing on this scale has been done before