Science Illustrated

Bubble Bath Sends Plastic To The Surface

The same principle that makes a straw leap out of your soda pop is applied to scoop plastic junk out of the oceans.

-

Not all ocean plastic is floating on the surface, ready to be picked up. Ocean plastic is distribute­d across the entire water column, complicati­ng large-scale pick-up.

Consequent­ly, a Norwegian company, PGS, has invented a solution inspired by a familiar phenomenon. When a straw is immersed into freshly poured soft drink, it will often exit the glass due to all the bubbles produced by the carbonic acid. PGS aims to lay out a tube with air holes at a depth of 40-50 m and pump air through the tube, converting the ocean into a huge bubble bath, which will carry plastic pieces to the surface. A scoop wheel directs the waste into a press, which compresses it into small, yellow "sausages", that can float on the surface, until they are collected and carried ashore for further processing.

such as Kvalvika not ending up as swelling cemeteries for the plastic waste of the world.

MICROPLAST­IC AGGRAVATES PROBLEM

Several places in the oceans such as in the Pacific, there are huge waste islands, where plastic waste collects due to ocean currents. However, the islands are not visible to the naked eye, as they primarily consist of increased concentrat­ions of microplast­ic, scattered from the surface and all the way to the ocean floor. Microplast­ic is plastic smaller than five mm. It occurs, when larger plastic products are broken down into smaller parts by sunlight over time.

The slight size of microplast­ic does not make the problem any easier, and the consequenc­es reach much wider than the Norwegian tourism industry. According to UN data, 99 % of all sea birds will have eaten plastic by 2050, if things do not change. In a 2016 study from the Technical University of Denmark, scientists discovered that almost one in four of the cods and herrings of the North and Baltic Seas had microplast­ic in their stomachs. The plastic is a problem, as it blocks out the fishs' natural food. At worst, the fish starve to death.

OCEANS MUST BE CLEARED OF PLASTIC

The plastic problem of the oceans could grow much worse in the future, and that has boosted the developmen­t of new technologi­es which can remove ocean plastic.

The Dutch Ocean Cleanup project aims to use 1-2-km-long containmen­t booms to collect about 50 % of the ocean plastic in the Pacific. The floating barriers are to be placed in gyres, i.e. major ocean currents which make the waste unite into large islands. Under those, a vertical barrier captures pieces with diameters measuring from about one cm to up to several m. Though the Ocean Cleanup project does not capture microplast­ic, the method can capture larger elements, before they turn into microplast­ic.

To remove the tiniest of plastic pieces, scientists from the Imperial College London have calculated that it is more efficient to place the cleaning technologi­es closer to the coast instead of in the large gyres. The plastic comes from the land, and according to the scientists, cleanup efforts close to the coast could remove 31 % of the microplast­ic over a period of 10 years, as compared to only 17 % in deeper waters.

One example of a near-shore solution is the Seabin, which is placed at the surface of the water in marinas and other areas near the coast. Seabin is equipped with a pump, which sucks the water – and the plastic waste – into a fibre bag. The water passes through the fibre bag, while the waste accumulate­s inside it. One Seabin can collect about 1.5 kg of plastic a day.

PLASTIC USED OVER AND OVER AGAIN

When the ocean plastic has been carried safely to the shore, it is important that it does not return to the waste system, which cannot handle the plastic, as it is difficult to break down. So, circular economy is the key to solving the problem of our unhealthy plastic consumptio­n. The model involves that new products will be made of recycled and renewable materials, if possible, and once the products are one day worn out, they will be recycled into new products. Luckily, this tendency is already here. Adidas has created trainers, which are partly made of fibres deriving from ocean plastic. If more plastic is recycled, and the major plastic spill to the oceans i s halted, the material’s environmen­tal drawbacks might one day be a thing of the past, and the only thing that remains will be the fantastic plastic.

 ??  ??
 ??  ?? THE PLANT COVERS AN AREA OF 200 KM2A DAY.
THE PLANT COVERS AN AREA OF 200 KM2A DAY.
 ??  ?? The Adidas apparel company has designed trainers, whose tops partly consist of plastic fibres made of reclaimed ocean plastic.
The Adidas apparel company has designed trainers, whose tops partly consist of plastic fibres made of reclaimed ocean plastic.

Newspapers in English

Newspapers from Australia