ELIMINATION OF PHARMACEUTICAL RESIDUES IN HOSPITAL WASTEWATER USING LOW AND MEDIUM PRESSURE UV LAMPS

摘要

The current work aims at investigating the decentralised elimination of Pharmaceuticals from hospital wastewater. The research study involved a pilot-scale membrane bioreactor (MBR) being connected to a representative wastewater stream of a hospital. The MBR process served as efficient pre-treatment while macropollutants (e.g. organic carbon, nitrogen, suspended solids) are reduced before energy intensive UV treatment has been applied to tackle the pharmaceutical elimination of the MBR effluent. The continuously gained permeate (MBR effluent) was linked to a UV treatment unit which was run in batch operation. Low and medium pressure UV lamps were tested for their efficiency to remove Pharmaceuticals from the MBR permeate. Furthermore, the UV treatment was operated in combination with different dosages of H_2O_2 to establish an advanced oxidation process (AOP). The efficiency of the pharmaceutical removal process was assessed with 9 micropollutants (antibiotics, analgesics, anticonvulsants, cytostatics, lipid regulators) which are typically released by hospitals. Liquid chromatography coupled tandem mass spectrometry (LC-MS/MS) was applied for their detection. While the MBR treatment showed generally only low degradation capacity for persistent Pharmaceuticals (e.g. diurnal removal rate of 25 % for diclofenac) promising results were obtained by applying UV irradiation and H_2O_2 as AOP. Moreover, comparing the electrical energy need in relation to the pharmaceutical degradation caused by the medium and low pressure UV lamp the latter appeared to have a considerable advantage in cost-effectiveness.