• Susan

Centralised recycling of nutrients in wastewater sludges

Gasum is developing new concepts to recover and recycle the nutrients in wastewater sludges.


Biogas technology has a key role in recycling the nutrients in sludges and in the production of renewable traffic fuel as part of energy efficient sludge processing. The processing of wastewater sludge and recovery of nutrients in concentrated, high quality forms has been an active subject of research in Finland and globally in recent years. Advanced processing methods often call for major investments, which justifies centralised processing.


The two year JÄRKKI – centralised recycling of nutrients in wastewater sludges project (in Finnish only) supported by the Ministry of the Environment seeks to combine new wastewater sludge processing technologies into centralised processing concepts and will use lifecycle assessment to evaluate their environmental sustainability.



‘Wastewater sludges are an important resource, and we are pursuing new processing solutions and applications, especially in the utilisation of nutrients,’ said Ari Suomilammi, director, biogas production, Gasum. ‘An holistic perspective is called for in sludge processing where existing and emerging technologies can be combined in the best possible way taking into account the logistics relating to the logistics of both the sludges and end products,’ added Viljami Kinnunen, senior development engineer, Gasum. ‘Logistics have an important role in the centralised processing of sludges and the project is using logistics modelling to look for suitable plant sizes and locations,’ explained Maritta Kymäläinen, principal lecturer at Häme University of Applied Sciences HAMK. The project is being implemented in collaboration with Gasum and HAMK – and involving a wide range of stakeholders through workshops.