This study shows the evaluation of the possible use of the freshwater bivalve Dreissena polymorpha for the
removal of some recalcitrant contaminants, namely many pharmaceuticals and drugs of abuse that are
not sufficiently removed from civil wastewaters. This mollusk has an enormous filtering capability and is
highly resistant to natural and anthropogenic stresses and to a significant bioaccumulation of lipophilic
contaminants. Allthese characteristics may be particularly useful for the removal of compounds not easily
eliminated by conventional wastewater treatment processes. To verify this hypothesis an experimental
study was conducted at the pilot scale using a pilot plant installed in the largest wastewater treatment
plant of Milan (Milano-Nosedo, Italy). First, we presented results obtained in several preliminary tests in
order to evaluate the capability of zebra mussel specimens to survive in different wastewater mixtures,
its filtering capacity and the possible influence of bio- and photo-degradation in the abatement of the
molecules of interest. Finally, data obtained in the final tests demonstrated a capacity of this filter-feeder
to reduce the concentrations of several pharmaceuticals and drugs of abuse higher than that obtained by
the simple natural sedimentation, suggesting a possible implementation of the bio-filtration process in
wastewater management.