SINGAPORE: Construction has begun on Tuas Nexus, Singapore’s first integrated waste and water treatment facility, said the National Environment Agency (NEA) and PUB in a joint news release on Tuesday (Sep 8).
Set to be completed in phases starting 2025, the facility is a co-location of two mega facilities – the Tuas Water Reclamation Plant (Tuas WRP) and Integrated Waste Management Facility (IWMF) – that will “help forge a more sustainable Singapore by optimising land use, and maximising energy and resource recovery”, said the agencies.
Tuas Nexus will be “energy self-sufficient”, the release said, by harnessing synergies from Tuas WRP and IWMF.
This is expected to result in carbon savings of more than 200,000 tonnes of carbon dioxide annually, equivalent to taking 42,500 cars off Singapore’s roads.
In addition, integrating the two facilities will result in land savings of up to 2.6ha – about the size of four football fields, as compared to building the two as standalone facilities, the release added.
“By employing the latest technologies, Tuas Nexus will harness the synergies of the water-energy-waste nexus from used water and solid waste.
“The by-product of one facility becomes a resource for the other facility,” PUB and NEA explained.
For example, IWMF’s Food Waste Treatment Facility will convert source segregated food waste into food waste slurry suitable for co-digestion with used water sludge at Tuas WRP.
The co-digestion of food waste and used water sludge will increase biogas production by 40 per cent at Tuas WRP, compared to biogas yield from treatment of used water sludge alone.
The biogas produced will then be combusted at IWMF and the combustion heat energy recovered to improve the overall plant thermal efficiency and boost electricity generation, said the agencies.
The electricity generated by IWMF will be used to sustain the operations of Tuas Nexus with excess to be exported to the grid. This excess electricity exported to the grid will be able to continually power up to 300,000 four-room HDB apartments.
THE MEGA FACILITIES
The Tuas WRP, PUB’s answer to “closing the water loop more effectively”, will have an initial treatment capacity of 800,000m3 per day – the equivalent of 320 Olympic-sized swimming pools of water.
“Unlike conventional water treatment plants, it is equipped to receive both domestic and industrial used water streams from two separate deep tunnels for treatment,” according to the media release.
In a first for Singapore, the Tuas WRP will also be capable of treating industrial used water to a “sufficiently high standard” for industries’ use, the agencies said.
Tuas WRP will also house the largest membrane bioreactor facility in the world.
“This will enable the plant to be more energy efficient while occupying less space compared to existing water treatment plants and avoid the need for a long sea outfall,” PUB and NEA said.
A NEWater factory that will be built on the rooftop of Tuas WRP will “significantly boost” PUB’s NEWater production capability as well, “further ensuring a robust and resilient supply of water for Singapore that can meet growing water demand and cope with the impact of climate change”.
As for the IWMF, NEA’s “response plan” to meeting Singapore’s solid waste management needs, it will be equipped with “state-of-the-art solid waste treatment technologies” to improve energy and resource recovery from waste.
“It is Singapore’s first integrated facility to treat incinerable waste, source segregated food waste and dewatered sludge from Tuas WRP, as well as to sort household recyclables collected under the National Recycling Programme (NRP),” said the agencies.
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When it is fully completed, it will also be Singapore’s largest waste incineration plant.
“IWMF will also be the most energy efficient yet and for the first time, integrate an operational food waste treatment facility and sludge incineration facility to achieve higher food waste recycling rate and greater synergy with WRP’s operations.
“In addition, the IWMF’s automated Materials Recovery Facility will consolidate all recyclables collected under the NRP to achieve greater economies of scale, higher sorting efficiencies and recovery yields for various recyclable waste streams such as metals, paper, and plastic,” NEA and PUB said.
“This will help boost Singapore’s overall recycling efforts and bring Singapore another step closer to realising its vision towards zero waste.”
BUILDING TUAS NEXUS THE “SMART THING TO DO”: PUB CHIEF EXECUTIVE
“We are building Tuas Nexus because it is the smart thing to do, as the sum would be far greater than its two parts,” said PUB chief executive Ng Joo Hee.
“I believe the Tuas Nexus advances the state-of-the-art in sustainable urban waste management and resource recovery, and establishes a new international benchmark for the field.”
The facility can take Singapore closer to its vision of a zero-waste nation, said the CEO of NEA, Mr Tan Meng Dui.
“Tuas Nexus is the world’s first greenfield project to harness the co-location synergies of two mega waste facilities for waste and water treatment.
“Besides being part of an integrated Tuas Nexus facility, the IWMF, on its own, will also be the largest, most advanced, efficient and integrated yet of our solid waste treatment facilities.
“The integrated facility shines the way for a more circular approach to resource management and brings us one step closer to realising the vision of a zero waste nation,” he said.