PART 2
CASE STUDY: SINGAPORE - ADVANCED WASTE MANAGEMENT IN A LAND-SCARCE COUNTRY
Overview of Singapore's Waste Management System:
The waste management process comprises the collection, treatment and disposal of waste.Â
Solid Waste Sources: Includes residential, commercial, industrial (medical, electronic, construction), and an increase in medical waste by 40% due to COVID-19.
Global Context: Municipal solid waste includes only a small fraction of medical waste. Of the 2 billion tonnes of global waste, 12% is plastic, while food, organic matter, and paper/cardboard dominate.
Disposal Methods: Once all that trash is collected, there are 3 main ways it is treated and disposed of:
1) By burning the trash in an incinerator and generating electricity
2) By dumping the non-incinerable waste at the Semakau Landfill
3) By dumping waste openly without any processing. Not a very fun fact, about 33% of global waste ends up in open dumps.
Singapore’s Strategy and Infrastructure:
Singapore is known for being densely populated, which has nearly 8,000 people per km², more than 17 times that of India and 200 times that of the U.S. Between 1970 and 2016, the amount of solid waste disposed in Singapore increased about 7-fold as its population and economy grew. Of the 7 million tonnes of waste generated in the country in 2019, more than half were recycled. Singapore is a very small country. It’s land scarce. So, the need to conserve land is very critical for Singapore.
The journey of a single piece of trash brings us to Tuas South Incineration Plant, the largest waste incineration facility in Singapore to date. This is one of four such facilities in the country which can convert waste into energy. The process is as follows -Â
Waste is collected from industrial, commercial premises and household premises and discharged into bunkers by about 600 trucks daily.
Cranes then grab and feed the waste into the incinerator at about 850 – 1,000 degrees, reducing volume by 90%. This then helps to conserve the space required for landfill.Â
Along the way, they have a magnetic separator. Ferrous and non-ferrous metals are recovered from the ash and the ferrous scrap metal is sold to a local steel mill for recycling. Ash is then transported from the ash pit to another facility.Â
Pollutants produced during incineration are treated before being released into the atmosphere, ensuring clean air is being discharged.Â
Water is converted into steam from the energy recovered from the combustion of waste. This water is then converted into high temperature, high pressure steam to run turbine generators. This is to produce electricity. 20% is being consumed internally, with the rest being exported to the national grid.Â
The rest of the non-incinerable waste and ash is transported by barge to the 350-hectare Semakau Landfill.
The total power generated by the four waste-to-energy incineration plants in Singapore, including Tuas South, contributes about 2–3% to the national electricity demand in the country. An upcoming waste-to-energy plant built by Mitsubishi Heavy Industries and water treatment company Hyflux will be able to incinerate 3,600 tonnes of waste per day while generating electricity to be self-sufficient and providing excess power to the national grid. Besides this, there are current plans to work together with the different government agencies, businesses as well as communities to look into how they can extend the life of Semakau Landfill.
Challenges and Innovations:
Semakau Landfill - The Semakau Landfill is covered with soil and planted with trees and shrubs. The island supports a coral reef and mangroves. At current rates, this landfill will be full by 2035, prompting initiatives to extend its life and reduce waste by 30% by 2030 as part of Singapore’s Zero Waste Masterplan.
Recycling Initiatives - The other strategy they are also taking is looking at the possibilities of recycling the incineration bottom ash, which is now known as NEWSand, and could be used for non-structural concrete, for example. To date, NEWSand has been used to create footpaths and benches, while tests are ongoing for its application in road construction projects.Â
Global Waste Trends - High-income countries generate 34% of global waste despite comprising only 16% of the population, while low-income countries contribute 5%. However, this trend is expected to shift as economic growth and population increases in low-income nations. For over two decades, China was the dumping ground for nearly half of the world’s scrap, with much of it originating from developed countries such as the U.S., U.K. and Australia. All that changed in 2018 when China imposed a blanket ban on 24 types of imported waste, citing the need to protect its environment and public health.
 What lessons can we learn from Singapore’s other previous landfills?Â
Long-Term Solutions:Â Landfills are a temporary fix for a growing issue, especially in land-scarce areas like Singapore.
Waste Management Costs:Â Effective waste management requires substantial investment, not just as an economic activity but as a public service.
Community Involvement: Citizen participation in waste reduction, recycling, and willingness to pay for services is crucial for sustainable waste management.
What are your thoughts on this? Did you know about these impressive steps taken by Singapore as a part of their waste management solutions?
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