[     Business case listing ](/en/case-studies "  Business case listing")



 

 

 

### **The client**

- 100,000 PE (people equivalent)
- Located in eastern Denmark
- 2-step plant with settling tank
- Biological treatment of organic matters, nitrogen, and phosphorus (including chemical precipitation of residual P)
- Primary sludge and biological excess sludge treated in digesters



 

 

 



### **The challenges**

- Køge-Egnens WWTP had been trying to optimize nitrogen removal through online control for several years without much success.
- The plant needed to increase its hydraulic capacity to treat a large amount of water during rain events.
- One potential solution was a costly extension of the plant and an increase of the volume in the settling tanks.



 

 

 

 

 

 



 

### **The solution**

- Hubgrade Wastewater Plant Performance digital solution was implemented to holistically optimize the utility’s operations.
- A feasibility study was performed to explore alternative solutions for Køge-Egnens WWTP.
- The study showed that increasing the hydraulic capacity during rain was possible through intelligent control.
- The study also showed that nitrogen removal could be improved and significant savings could be achieved.
- The proposed solution allowed an increase of at least 35% and up to 60% in hydraulic capacity, while also improving nitrogen removal and providing significant savings in operation.



 

 

 

 

 

 



 

 

 





 

 


### KEY FIGURES

- M3 treated per day: 432,000
- Effluent requirements: BOD=15mg/L
- COD=75mg/L; Total-N=8mg/L, Total-P=1.5mg/L
- 35% reduction in electricity consumption
- 60% reduction in chemical consumption
- 100% increase in hydraulic capacity while improving the effluent quality on BOD and Total-N