Dublin City Council extends wastewater treatment plant

Due to additional demands on the Ringsend Waste Water Treatment Plant (WWTP) Dublin City Council awarded a project to Celtic Anglian Water and Enpure Limited to upgrade the Ringsend (WWTP).    This project is for an extension to the massive Ringsend works that treats Dublin’s sewage.   The work will comprise increasing additional capacity for the treatment of sludges by the upgrading and extending of the existing pre-treatment and anaerobic digestion facilities.

In November last year Enpure issued a major order to Cambi (Norway) for the supply of an additional 4-reactor stream and further digested sludge cooling facilities to run along side the existing twin streams of the Cambi Thermal Hydrolysis plant (THP).   To enable Dublin City Council to cope with the increasing demand on the processing capacity for sludge treatment in the Dublin City area, this necessitates increasing the capacity in the following key areas:  

• Sludge processing capacity (additional 4 reactor Cambi THP)
• Steam generation capacity
• Dewatering capacity
• Digester capacity
• Digester cooling capacity (additional Cambi sludge cooling package)

  Due to the relatively small footprint of the Cambi system it is possible to house the additional 4-reactor stream within the same building as the original Cambi plant.   This makes sound financial sense and enables integrating the additional stream with the existing Cambi plants a relatively straight forward operation.    The addition of extra cooling facilities as part of the upgrade will ensure digester temperature is maintained at the optimal level for biogas production and to cope with the increased throughput of the digestion process.   The existing Cambi 8-reactor THP plant was designed to treat 36,000 tonnes DS sewage sludge annually.   After the upgrade the total THP plant will be capable of handling 57,000 tonnes DS sewage sludge annually.   Increasing the digester capacity will also have the benefit of increased biogas production which can be utilized in the CHP to produce additional electricity / steam to help power the complex.   The upgrade will also enable Dublin City Council to meet its increased demand well into the future.   The completed third THP stream is scheduled to be in operation by late November 2009.