Biological sulphate reduction in wastewater treatment

The sludge line accounts for about one-quarter of total wastewater treatment costs. Minimising the volume of excess sludge would therefore lead to considerable cost savings. Sulphate-reducing bacteria (SRB) could possibly make a contribution.


Sulphate-reducing bacteria enable a stable removal of organic matter with a small increase in sludge volume. Other advantages of the application of SRB in wastewater treatment are the formation of granules, the removal of heavy metals, the reduced energy consumption and a decrease in pathogens. This research tested the application of SRB on domestic wastewater at low water temperatures (10°C) on a pilot scale.


Pilot-scale research was conducted for over half a year at Delfluent’s Harnaschpolder WWTP. The pilot reactor was designed and installed by Paques. The operational management was conducted in part by KWR. The research focused on the degree of the SRB activity when they are applied to domestic wastewater at low temperatures, and on an optimal process management.


This research demonstrates that SRB, at the relatively low temperature of 10°C, efficiently remove organic matter from domestic wastewater. The results of the pilot and of the research on optimal process conditions are set out in a report.