Story
WHAT IS SLUDGE?
“Sludge” is a thick mud-like by-product of sewage treatment. It needs proper and sophisticated handling in order to build a sustainable future for Hong Kong. We produce close to 3 million cubic meters of sewage, which results in approximately 1,200 tonnes of sludge every day.
Source of Sludge
Sewage, for example from toilet, cooking and washing, etc., generated from our daily lives is collected and treated in Sewage Treatment Works before discharging into water bodies. Upon the Chemical Enhanced Primary Treatment and Secondary Treatment of sewage, sludge is produced for proper and safe disposal.
Composition of Sludge
There are 11 major Sewage Treatment Works in Hong Kong. The Stonecutters Island Sewage Treatment Works produces almost 70% of the total sludge in the territory.
THE WASTE CHALLENGE
Over the years, landfilling has been the only means of sludge disposal. That is no longer a sustainable waste management solution due to a substantial increase in the amount of sludge to be disposed, resulting from the increasing population and various upgrading and improvement works of sewage treatment systems, including the Harbour Area Treatment Scheme, shortened the lifespan and affects the stability of our landfills.
Harbour Area Treatment Scheme
The HATS aims to improve the water quality of Victoria Harbour by collecting and treating sewage generated from both sides of the harbour. The project has been implemented in two stages. Facilities under Stage 1 were commissioned in December 2001, providing treatment for 75 per cent of the sewage generated from both sides of the harbour. The works of Stage 2A commenced in July 2009 and it started operation in December 2015. Through this process, the remaining 25 per cent of sewage from the northern and southwestern parts of Hong Kong Island, which previously received only preliminary treatment, will be redirected to the newly expanded Stonecutters Island Sewage Treatment Works for chemically enhanced primary treatment, meaning that sewage will no longer be discharged to Victoria Harbour.
THE AMOUNT OF SLUDGE IS ESTIMATED TO GROW TO 2,000 TONNES PER DAY IN 2030
THE SOLUTION
Burning is a highly effective method of sewage sludge treatment. Advanced incineration technology through the high-tech thermal process is adopted to ensure efficient and reliable treatment of sludge. With two plants of 4 incineration trains in the facility, T · PARK can handle a maximum capacity of 2,000 tonnes of sludge per day.
POWER GENERATION
The heat energy generated from the incineration process is recovered and turned into electricity that can support the needs of the entire facility. When running at full capacity, it can produce up to 2 megawatts (MW) of surplus electricity for the public power grid, which is an impeccable example of “waste-to-energy” in action.
SURPLUS ELECTRICITY TO
SUPPORT UP TO
SLUDGE TO ASH
After incineration, sludge will be converted into ash and residues – a total reduction of 90% of the original sludge volume. This dramatically cuts down the quantity of waste to be disposed of in the landfills and reduces the emission of greenhouse gases by up to 237,000 tonnes a year.
ASH AND RESIDUES
GREENER FUTURE
T · PARK is a futuristic waste treatment facility that fires up Hong Kong’s “waste-to-energy” and resource recovery ambitions. It offers the best alternative solution for sludge disposal and sets the pace for a more sustainable Hong Kong.