Dublin - Ringsend

Dublin - Ringsend

Ringsend Wastewater Treatment Works needed to manage increasing sludge volumes following the adoption of Sequencing Batch Reactor (SBR) secondary biological treatment. This produced difficult-to-dewater sludge and could have required a threefold increase in drying capacity. The plant therefore needed a compact solution that would reduce biosolids volumes and minimise additional drying requirements.

In the early 2000s, the facility installed two Cambi Thermal Hydrolysis Process (THP) streams as pretreatment for anaerobic digestion. THP improved sludge dewaterability, reduced sludge volumes, and optimised the space required for the expansion. Crucially, it limited the necessary increase in drying capacity to 50%. It also halved the required digester volume and increased biogas production, supporting on-site energy recovery and carbon-reduction goals. The resulting intermediate digested cake is a pasteurised product used for agricultural applications in the Dublin area.

A third THP train was added in 2009 and upgraded in 2024 to meet rising demand.

In 2026, Cambi signed an agreement with Celtic Anglian Water to extend the service life of the first two THP trains, with completion planned for the end of 2027.