Long term trials with membrane bioreactor for enhanced wastewater treatment coupled with compact sludge treatment - pilot Henriksdal 2040, results from 2019

Henriksdal wastewater treatment plant in Stockholm is currently being extended and rebuilt for increased capacity and enhanced treatment efficiency. The new process configuration at the Henriksdal WWTP has been designed for a capacity of 1.6 million population equivalents which is about twice as much as today. The reconstruction will include retrofitting of the existing conventional activated sludge tanks with a new membrane bioreactor process containing 1.6 million m2 of membrane area.

To increase the knowledge on membrane technology for wastewater treatment in Nordic conditions, long-term MBR pilot scale studies are conducted, since 2013, at the R&D facility Hammarby Sjöstadsverk in Stockholm.

Results from previous years have verified that the process is able to treat a hydraulic load equivalent to the design load, and a nutrient load greater than the design load, to effluent concentrations below the future discharge limits. In addition, the function and resilience of the membrane design have been verified.

During 2019, a large focus was put on digester transition from mesophilic to thermophilic condition, increased efficiency in membrane operation, membrane cleaning, phosphorus removal, testing of external carbon sources, reducing HRT in the digester and mapping of micro pollutants in the system.