Recovery of ammonia to reduce load on the existing nitrification and denitrification system.

The challenge

The effluent from the sludge digester of the new Bergen auf Rügen sewage sludge treatment plant creates a major load on the existing biological water treatment plant. Instead of a traditional anammox system system Byosis offered an alternative solution by integrating the ByoFlex^® ammonia stripper.

Our approach

By removing and converting the ammonium from the effluent of the digester with the ByoFlex^® technology, the existing nitrification and denitrification installation is now fed with effluent with over 80% less ammonia. Especially valuable in summertime when the loads are extra high as result of the tourist season.

The system is easy to start up and shut down. When the excess nitrogen load is low (e.g. in wintertime) the throughput or efficiency can be reduced or bypassed (and the installation is stopped), but the system is readily available on demand and back to full capacity in less than an hour.

The results

The installation reduces the nitrogen load of the biological treatment. Additionally, this creates a valuable circular process. The recovered nitrogen is, as ammonium sulphate, reused by the farmers on the island as a fertilizer. This gives a significant reduction of the use of artificial fertilizers on the island.

Specifications and features

• 5-7 m3/hr system ByoFlex^® system.
• Built in prefab skids which form a closed building.
• Minimal heat requirement due to heat recovery.
• No addition of alkaline agent 
• >80% less nitrogen load on the biological treatment.
• Production of a high value fertilizer for local farmers.
• Significant reduction of the carbon footprint of the overall process