C. Kragelund, Danish Technological Institute*, G.T.H. Ooi & K. Tang, Technical University of Denmark**,
A.T. Christensen, Danish Technological Institute*, K. Bester, Aarhus University***, H.R. Andersen,
Hospitals are widely considered as large contributors to point source pollution of pharmaceuticals due to
their discharge in wastewater. However, there are no recommendations as to what
... [Show full abstract] technology to use or
where the hospital wastewater treatment should be conducted (selected sidestreams, main stream or at the
municipality). The MERMISS project developed and optimized a new technology concept where the
biological removal was biofilm-based, namely the Moving Bed Biofilm Reactors (MBBR), where the
biofilm attached to plastic carrier material. However, not all pharmaceuticals can be removed biologically
and therefore an ozonation step has been included in the MERMISS technology concept. Different test sites
were examined ant at different scale.
A lab scale set up was tested on a toxic sidestream from the dept. of Oncology and the served as a prove of
concept (Casas et al., 2015 a,b). Superior biological removal was observed for selected medium
biodegradable compounds and hardly degradable compounds compared to conventional activated sludge, as
shown in figure 1a. Both MBBR and a mixture of activated sludge and MBBR (HYBAS) configuration was
tested. Based on these promising results, a pilot scale plant was build and tested during 11 months
exclusively fed on main stream of hospital wastewater. The plant functioned as a conventional wastewater
treatment plant (removal of C, N and possibility of P) beside a significantly enhanced removal of
pharmaceuticals (Tang et al., in prep). The staged-MBBR showed a remarkable potential to remove 23 out of
the 25 pharmaceuticals up to at least 30%. The aerobic steps (M2, M3a,b, M5) showed the highest removal
capacity, as shown in figure 1b. Also, the anoxic steps contributed to the overall degradation of the
persistent pharmaceuticals in denitrifying MBBRs such as venlafaxine and trimethoprim (M2 and M4).