ABOUT THE CLIENT
HOSPITAL WASTEWATER IN DENMARK
Herlev Hospital is a 900-bed Danish university hospital situated close to Copenhagen. As hospital wastewater contains hazardous pharmaceuticals and can cause serious infectious diseases, the environmental authorities have required that the wastewater is to be treated before being released to sewers and the aquatic environment.
WHAT THE CLIENT NEEDED
AN ADVANCED AND ROBUST WATER TREATMENT SYSTEM
Herlev Hospital needed an advanced and robust treatment system to remove both hazardous substances, like active pharmaceuticals, and pathogens like antibiotic-resistant bacteria. Since May 2014, all wastewater from Herlev Hospital has been treated by the ULTRAAQUA treatment technology. The technology is able to treat the wastewater so efficiently that it is no longer toxic to aquatic organisms, thus not harming the ecosystem when released directly 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. No traces of viruses can be measured too.
With the implemented full-scale solution, the wastewater can now be used for recreational purposes in the local stream (Kagså) and re-used for irrigation and as cooling water in the hospital.
THE SOLUTION
STATE-OF-THE-ART WATER POLISHING TECHNOLOGY
The developed treatment process consists of a so-called membrane bioreactor (MBR) which carries out the biological treatment and filtration of the wastewater, to remove the organics and nutrients.
The MBR process is followed by a combination of polishing technologies that remove all critical pharmaceuticals and pathogens that remain in the water. The ULTRAAQUA polishing technologies consist of ozonation, activated carbon (GAC) and UV treatment.
ULTRAAQUA has in-depth knowledge on which technologies can remove each of the hazardous pharmaceuticals. ULTRAAQUA has followed the treatment performance since 2014 in close cooperation with Herlev Hospital. The polishing technologies are continuously being cost-optimized, while consistently complying with the strict discharge requirements for both pharmaceuticals and microbiology. The activated carbon (GAC) process is, as an example, optimized to a consumption of only 7-8 mg/l and still holds the high removal rates of the micropollutants.
An overview of the treatment results is shown in the table below.
Table 1 – Overview of treatment performance. From raw hospital wastewater to final treated effluent
| Parameters | Raw untreated wastewater | Treated wastewater |
| Toxic and persistent antibiotics (e.g. ciprofloxacin, clarithromycin and sulfamethoxazole), painkillers (diclofenac) and cytostatics (e.g. capecitabine) | Factor 10-300 exceeding of effect limits (PNECFreshwater) for water living organisms | 99.9% removal and no exceeding of effect limits (PNECFreshwater) for water living organisms |
| Contrast media (e.g. iomeprol) | High concentration (2,5-7 mg/l) | 99% removal |
| Antibiotic resistant bacteria | High occurrence of antibiotic resistant bacteria | No fecal or antibiotic resistant bacteria |
| Water born viruses (norovirus) | High concentration (1.7·105) | Under limit of detection (<26 GC/l) |
| Fish fry (zebra fish) | 100% mortality within 96 hours | 0 % mortality within 96 hours |
| Crustacean (daphnies) | No offspring (all test animals died) | Offspring survives as in clean control water |
| Estrogenic activity (A-YES) | Estrogen effects | No estrogen effects |
