Cleantech company C-Green Technology, IVL Swedish Environmental Research Institute and municipal-owned water and waste company Roslagsvatten are joining forces to build the world’s first sludge-free wastewater treatment plant.
Handling wet sludge is a problem all over the world. Globally, hundreds of millions of tons of sludge requiring treatment or disposal are produced each year – a problem that is expected to increase as society and industry expand, therefore increasing the need for viable treatment methods.
Since sludge often contains both hazardous substances and harmful microbes, it is difficult to handle in a sustainable way. However, sludge also contains nitrogen, carbon and phosphorous which are valuable and should be recycled.
C-Green has developed a patented solution that makes use of hydrothermal carbonisation (HTC) to convert sludge to bio-coal in just a few hours. The process is called OxyPower HTC. It converts the wastewater sludge to a dry, sterile and biobased coal product, which has many environmental benefits. This produced bio-coal can then be used as biofuel or in the agricultural sector. This leads to less sludge and transportation of the sludge and a decrease in greenhouse gas emissions by about 80 %.
The project will start out as pilot tests, to build a full wastewater treatment plant in Margeretelund in Stockholm.