A Circular Way to Close Our Waste Loop
Close the Waste Loop
Great-billed heron call on it. Sea urchins and nudibranchs thrive in it. And there’s a fish farm off its shores We’re talking about the Semakau Landfill: the offshore site that holds all the trash of Singapore’s 5.6 million people.
Ideal as it is for biodiversity, this only landfill that we have is running out of space — fast. In fact, at the rate people are generating waste, the site will be completely filled by 2035. We need to reduce what we throw out. As outlined in the Singapore Green Plan 2030, our goal is to crunch back waste by a fifth by 2026, extending the lifespan of Semakau.
Start Thinking Circular
Banish the linear “take, make, throw” mindset. We must stop taking raw materials to make new products only to eventually throw them out. Instead, adopt a circular approach. That is, recover materials at the end of a product’s life cycle and channel them back into production.
Why is a circular economy important? By keeping materials in use in an endless loop, we can ease the pressure on the Earth’s limited resources, reducing waste and our carbon footprint.
Then how is Singapore moving towards a circular economy? By closing our resource loops, that’s how! Just as we have closed the water loop, almost all our construction waste and metals are recycled. Also, research and development (R&D) programmes such as the Closing the Waste Loop initiative drive innovation and improve the ways we turn trash to usable treasure.
One such R&D project is NEWSand, where ash from our incinerated waste is turned into construction material. In fact, a footpath near Our Tampines Hub and the plaza in front of the Environment Building at Scotts Road were constructed with NEWSand. Diverting incineration ash for construction purposes reduces the amount of ash that is landfilled in Semakau, helping to extend its lifespan.
Changemakers At Work
It’s not only the government agencies that are investing in new technologies and research to reduce waste. Many industries and businesses are also fighting the good fight in tackling packaging, electrical and electronic waste (e-waste), and food leftovers. They reimagine, repurpose and reuse everything from grit to grub to do so.
Take plastics. Home-grown start-up Margorium is turning plastic trash into road construction pellets. Using its own technology, it converts used plastics — from bottles, bags, milk cartons — into pellets that are added to asphalt when paving roads.
On how e-waste is being kept in check, look no further than a research laboratory right on home shores, the Singapore CEA Alliance for Research in Circular Economy (SCARCE) at NTU. Here, scientists work on eco-friendly ways to extract metals like cobalt and nickel from used batteries to reuse in new lithium ions that go into anything from mobile phones to laptops.
Then, there’s food waste. In 2020, Singapore generated enough kitchen and dinner scraps to equal the weight of 46,000 double decker buses. Only about 19 per cent of those leftovers were recycled.
Enter maggots and food pulp. There are companies here that convert and recycle food waste through a process called food resource valorisation, transforming scraps into higher-value food, feed or fertiliser.
- Insectta — maggots of the black soldier fly are this biotech firm’s arsenal of choice. At Insectta, thousands of larvae gobble up tons of leftover pulp sourced from soya bean factories and beer breweries daily. The grub is then served up — live, dried or ground — as feed and fertiliser. Insectta also extracts from the larvae bio-ingredients such as chitosan that are used in cosmetics and pharmaceuticals.
Crust — this food tech start-up transforms surplus bread and discarded fruit peels from food retailers into its line of beers and non-alcoholic beverages. The process: heat treatment and fermentation.
- Asia Pacific Breweries Singapore — it partners with a vendor to repurpose spent grains into animal feed.
- Academia’s upcycling of okara — that’s the high-fibre and high-protein discard of soymilk and tofu production. At least 30 tonnes of okara are dumped daily, so recycling saves Semakau from unwanted top-ups. Researchers at the Nanyang Technological University ferment okara and extract a liquid that gets animal cells to grow, creating lab-cultured meat. The team at the Republic Polytechnic uses okara as the main — and cheaper — ingredient in abalone feed, breeding plumper versions of the seafood. Food scientists at the National University of Singapore have converted okara into a probiotic drink.
Benefits for All
Certainly, Singapore is making headway in closing our waste and resource loops. And our efforts towards a circular economy are being recognised. For example, Magorium’s co-founder Oh Chu Xian was among 32 people in Singapore who were included in Forbes’ 30 Under 30 Asia list in 2021.
That’s not all: our circular economy drives cost savings and creates the potential for new market segments and jobs. For example, CRUST’s beers and non-alcoholic beverages open up new revenue streams. APB also saves on used grain disposal fees by turning tonnes of spent grains into animal feed.
Whether the innovators use microbes to turn food scraps into compost or reprocess plastic garbage into road-paving pellets, the idea is to lighten the burden on the environment by maximising the value of resources and minimising waste.
All said, if there’s one thing a circular approach brings about, it’s this: not only can we make life good, we can make living better.
