Monitoring, investigation and analysis of pathogens in MBR treated water at Hammarby Sjöstadsverk, Stockholm

This report summarises the findings from operations with AQUA-Q’s online real-time water quality monitoring system on the effluent from a pilot Membrane Bioreactor (MBR,) within the co-financed VINNOVA-project entitled Tomorrows Sewage Treatment Plants – A Utility Production Facility (Morgondagens kommunala vattenrening – en produktionsanläggning för nyttigheter). Significant progress has been made during recent years with regard to real-time water quality monitoring systems for monitoring and control of water quality and water treatment operation. This report provides an evaluation of the efficiency of the MBR process at the R&D-facility Hammarby Sjöstadsverk, Stockholm, Sweden. This includes the monitoring of larger contaminants (>0.2mm) in effluent water of the MBR process. Aqua-Q’s early warning system, WQM-100, has monitored the water quality 24/7 during the spring 2014 and the particle/micro-contaminants removal efficiency of the MBR was evaluated. Aqua-Q’s real-time monitoring system detected that one of the membranes (membrane A) of the MBR-process had a constant leakage of micro-contaminants. Periodic variations in the measured micro-contaminants concentration could have been caused by an overload in MBR process and also by a potential filter breakthrough. However, during the test period no significant problems were observed in the MBR-process control. For evaluation and verification of the indication from Aqua-Q’s real-time monitoring system, complete microbiological analyses were performed with an alternative ISO standard method and by a certified environmental laboratory. The results highlight the importance of real time quality monitoring of processes related to human sources of microbiological growth. Therefore, a better understanding and control of water qualities in water treatment processes is cost and resource effective, and reduces microbiological emissions to the environment.