Cleaning Up the Ocean: Technology to the Rescue

By Eunice Ruth | Published: 2:00 AM Apr 17 2021
Focus Cleaning Up the Ocean: Technology to the Rescue

By Eunice Ruth

Watching the sea from the shore will not make you realise how the people have harmed it. Oceans around the world, including Sri Lankan water bodies, have gone through a remarkable transformation over the past several decades, due to the increasing pollution rate. Cleaning them up using vessels and nets would take thousands of years to complete. However, with the help of technology, we can reduce and prevent pollution within a small period of time compared to vessel and net methods. 

Waste including plastic and others have turned up everywhere, transported by air, rain, and in other ways. Importantly, in the ocean, plastic can look like food to marine life. Not only is it dangerous and potentially deadly to animals, it also increases the amount of toxins in marine life and humans, who eat seafood. In addition, the ocean is being depleted of critical fish stocks, choked with discarded plastic, and made increasingly acidic from increased carbon emissions absorbed from the air. If things continue as they are, experts estimate that by 2025 there will be a ton of plastic in the ocean for every three tons of fish.

Though our oceans have undergone a dramatic transformation, these changes aren’t permanent and it can be minimised with the help of modern technology. It’s possible to implement new technologies and restore our aquatic ecosystems. The world has started moving with the help of technology. Still, Sri Lanka has not adapted to it. However, there are several measures which can be taken with the help of technology, which can be used to reduce ocean pollution. It may not be an easy task to commence at once and it is much more expensive than what we expect. However, we can still adapt to it to prevent and minimise ocean pollution. After commencing the process using modern equipment, water bodies including oceans and canals can be cleaned by collecting floating waste and other underwater waste.

How technology can help to clean up the ocean

Coordinator of Pearl Protectors, Muditha Katuwawala, said globally, several organisations use advanced technologies to get rid of the world’s ocean pollution. They use satellite imagery and machine learning to help in the clean-up. Sand cleaning machines, plastic roads, underwater drones, and air bubble barriers are some of the methods used in other countries to reduce ocean pollution. 

“As a country which is currently facing a lot of marine issues, we can also adopt these measures. It may take time, and it will take a substantial investment, but we can’t afford to dismiss this important responsibility.” We should be responsible enough to support our country to build and restore the aquatic ecosystem, he said.

Plastic roads

India has been leading the world in experiments to recycle discarded plastic. They started experimenting with plastic-tar roads from the early 2000s and several other countries are following suit to reduce plastic pollution. 

“Even Sri Lanka tried to implement this two years ago and the pilot project took place in Ratmalana. However, it has not moved to the next stage and it should be implemented within the country to protect the environment,” Katuwawala said.   

Plastic roads are one of the best ways to reduce ocean and environmental pollution by recycling the discarded plastic into the road. Blending plastic into roads and pathways helps reduce carbon emissions, keep plastic from the oceans and landfills, and improve the lifetime of the average road. These plastic roads replace 10 per cent of a road’s bitumen with repurposed plastic waste and it is expected by the end of 2040, there is set to be 1.3 billion tonnes of plastic in the environment globally. 

He added that it has the benefit of being a very simple process, requiring little high-tech machinery. First, the shredded plastic waste is scattered onto an aggregate of crushed stones and sand before being heated to about 170C, hot enough to melt the waste. The melted plastics then coat the aggregate in a thin layer. Then heated bitumen is added on top, which helps to solidify the aggregate, and the mixture is complete. Many different types of plastics can be added to the mix such as carrier bags, disposable cups, hard-to-recycle multi-layer films and polyethylene and polypropylene foams. 

As well as ensuring these plastics don’t go to landfills or oceans, there is some evidence that the plastic also helps the road function better. Adding plastic to roads appears to slow their deterioration and minimise potholes. Also, the plastic content improves the surface’s flexibility, by helping it to cope better with expansion and contraction due to temperature changes.

Air bubble barrier

This innovation can address the mounting crisis of plastic waste in the ocean. The bubble barrier is a long, perforated tube running diagonally for 60 metres across the bottom of the canal. Compressed air is pumped through the tube and rises upwards, and then the natural water current helps to push waste to one side. It is trapped in a small rubbish platform on the side of a particular canal.

The air bubble barrier is a simple device that channels rubbish, especially, small pieces of plastic to a corner of the canal where it can be retrieved. It can divert more than 80 per cent of flotsam and more than two-thirds of plastics in the ocean come out of rivers and canals using this equipment. 

Sand cleaning machine

A sand cleaning machine is a vehicle that drags a raking or sifting device over beach sand to remove rubbish. It is an effective way to clean the beach, as it can clean the whole beach. They are manually self-pulled vehicles on tracks or wheels or pulled by quad bikes or tractors. Seaside cities use beach cleaning machines to combat the problems of litter left by beach-goers and other pollution washed up on their shores. These beach cleaning machines work by a dragging mechanism to collect all the waste, such as sticks, stones, litter and other items. 

Different technologies can be used in this sand cleaning machine. Raking technology can be used on dry or wet sand. When using this method, a rotating conveyor belt containing hundreds of tines combs through the sand and removes surface and buried debris while leaving the sand on the beach. Raking machines can remove materials ranging from small pebbles, shards of glass, and cigarette butts to larger woods. By keeping the sand on the beach and only lifting the debris, raking machines can travel at high speeds.

Sifting technology is practised on dry sand and soft surfaces. The sand and waste are collected via the pickup blade of the vehicle onto a vibrating screening belt, which leaves the sand behind. The waste is gathered in a collecting tray which is often situated at the back of the vehicle. Because sand and waste are lifted onto the screening belt, sifters must allow time for the sand to sift through the screen and back onto the beach. The size of the materials removed is governed by the size of the holes in the installed screen.

Meanwhile, combined raking and sifting technology differs from pure sifters, in that it uses rotating tines to scoop sand and debris onto a vibrating screen, instead of relying simply on the pickup blade. The tines’ position can be adjusted to more effectively guide different-sized materials onto the screen. Once on the screen, combined raking and sifting machines use the same technology as normal sifters to remove unwanted debris from the sand.

Underwater drone

With an underwater drone you can explore lakes and oceans like never before. You can use them for leisure, research, fish-finding, hull inspection, treasure hunting, and more without getting your feet wet. When using it for research, it can show you the waste which has been dumped underwater. This will be very useful to monitor, as we cannot clean the deep sea using our hands. The shore and the upper level can be cleaned by scuba divers and other volunteers. 

Underwater drones are considered remotely operated vehicles (ROVs), and most, even those you see on deep-sea exploration vessels, are attached to the parent ship by an umbilical cord. When it comes to consumer models, it is usually called a tether. At one end it is attached to the drone, at the other to a control unit. Actual control is usually via a mobile app that links to the controller by Wi-Fi. The length of that tether is going to have a big impact on potential uses. 

The major features will be image capture, and most can record 4K video. Control functions of the drone vary and in general the more thrusters you have, the better you can handle the drone in terms of depth and direction. Also, the lights can be useful, particularly in murky water. Some underwater drones also have sonar, so that they can avoid obstacles and feed topographical information back to your application.

Katuwawala said there are opportunities where we can use this technology and equipment in Sri Lanka. However, when we think about the investment, it is not easy to implement the project within the country. This equipment and technology can be imported or even designed and produced in our country. This project can cost billions and it will be very expensive to import the necessary equipment. He also added that, more than importing, using Sri Lankan innovations will be more effective, as it can clean the ocean and help the innovator. Meanwhile, we are planning to implement this in the country, with the help of university students. With their help, proper research can be conducted regarding the current pollution status and we can begin the process with their innovations and ideas. We can buy the invention from the inventor, which will also motivate the inventor to invent more items which will help the country, he added. 

By Eunice Ruth | Published: 2:00 AM Apr 17 2021

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