Ash from incinerated sewage is being used to create millions of bricks in London.
Thames Water is driving the project, which turns the waste material into an aggregate used in breeze blocks.
Solid waste from sewage is already incinerated on site at Thames Water’s Beckton plant and used to to generate electricity for the facility. Remaining sterile ash previously being dumped in landfill.
Thames Water has now signed a deal with an unnamed contractor to provide them with the ash needed to create the breeze blocks.
The ash will be supplied to the external contractor, to be reacted and mixed with carbon dioxide, water, sand and cement to form aggregate for 17kg breeze blocks.
The process captures more carbon dioxide than the initial incineration creates, meaning the bricks act as small-scale carbon storage.
Under the terms of the deal, Thames Water will supply ash to make 18,000t of the aggregate, enough for 2.3M heavy-duty bricks.
Thames Water head of wastewater treatment Nigel Watts said: “We’re transforming tonnes of waste from our sewage treatment process into a useful product, which can be used in construction in a variety of ways. It’s amazing to think that what’s flushed down the toilet could light up your bathroom and now help build homes, helping to support the huge growth predicted for our region.”
He added: “We’re always looking for alternative, more sustainable ways to dispose of waste that avoids landfill and this is fantastic news for our customers, putting downward pressure on bills, and the environment, which we work hard to protect and enhance,” he added.
Using the ash will save the equivalent 18,000t of aggregate from being mined from the ground, saving 800t of carbon dioxide in the process.
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