Berson's medium pressure UV systems are being used in a trial in the Netherlands to treat hospital wastewater prior to discharge. In the trial, UV is applied in combination with hydrogen peroxide (H2O2) to generate OH-radicals in a so-called “Advanced Oxidation Process” (AOP). The very reactive OH-radicals attack the pharmaceutical residues in the wastewater, breaking them down into H2O, CO2 and harmless metabolites.
Like all hospitals, the wastewater from the Isala Hospital in Zwolle, the Netherlands, contains elevated levels of X-ray contrast compounds and various other pharmaceutical residues.
Prior to UV/H2O2 treatment the complete wastewater stream is pre-treated in a membrane bioreactor (MBR). The wastewater then passes through a Berson InLine medium pressure UV system, into which specific amounts of H2O2 are injected. The treated wastewater is then discharged as treated sewage into the municipal sewage system.
This is the first full-scale trial for the treatment of hospital wastewater in Europe and is part of the Europe-wide PILLS project that is investigating which treatment methods are best suited to eliminate pharmaceutical residues from hospital wastewater. At present wastewater plants are not able to remove such residues from wastewater.
Even though it is unclear what effects these residues have on the water habitat, studies have shown that there is a link between elevated levels of substances such as the hormone ethinylestradiol, which is contained in contraceptive pills, and the reproductive rate of fish. The removal of these and other potentially harmful compounds is therefore a priority.
“The pilot plant is going well and Waterschap Groot-Salland, the local water authority that runs the project, has given me very good feedback so far,” said Peter Menne, Berson's European sales manager, about the installation. “An additional benefit of this system is that it requires high doses of UV, which is extremely effective at destroying any micro-organisms present in the wastewater,” he added.