25 Aug 2016

Hospital wastewater – From a pollution problem to new water resources

Hospital wastewater contains hazardous pharmaceuticals and can cause serious infectious diseases. Hence, it is paramount that hospital wastewater be treated before being released to sewers and the aquatic environment. DHI has, together with Grundfos BioBooster A/S, tested, developed and evaluated a new type of method to treat the wastewater. With the full scale treatment, it is now possible to efficiently clean wastewater such that the treated water produced can be used for recreational purposes in the local stream and be re-used as cooling water in the hospital.

The newly developed treatment process consists of a so-called membrane bioreactor (MBR) which carries out the biological treatment of the wastewater as well as a complete removal of bacteria. The MBR process is followed by a combination of polishing technologies which remove all critical pharmaceuticals that remain in the water. The polishing technologies consist of ozone, activated carbon, and Ultraviolet (UV) rays to eliminate toxic chemicals that exist in the wastewater.

Since May 2014, all wastewater from Herlev Hospital has been treated by this new treatment technology. After two years of operation, the treatment and economic efficiency of the technology is evaluated. The evaluation reveals that the technology is able to treat the wastewater of pharmaceuticals efficiently that it is no longer toxic to aquatic organisms, thus not harming the ecosystem when released to the aquatic environment. Further, the technology is also effective in removing all traces of bacteria, including antibiotic resistant bacteria which cause hard-to-treat diseases. 

With the new technology, the wastewater treatment plant is able to better treat hospital wastewater to
rid of bacteria and toxic chemicals. © Grundfos

Herlev Hospital has ensured that all the wastewater produced by the hospital is treated before either released to sewers and the aquatic environment, or re-used in hospital operations. Grundfos BioBooster A/S has provided the plant and is overall responsible for the project, UltraAqua A/S has provided ozone, activated carbon and UV, whilst DHI is responsible for the testing, development and evaluation of the technology.

To learn more about the technology, access DHI's evaluation report "Full scale advanced wastewater treatment at Herlev Hospital - Treatment performance and evaluation" as well as a Danish summary of the report.