showed a
lower difference compared to control than the previous tests,
probably due to an excessive presence of suspended particulate
matter that determined a stress condition to the animals, which
may require a longer time than 4 h to acclimate and begin the
filtering process. Moreover, we cannot exclude the possible
presence of toxic compounds into the inlet of WWTP that could
have led to a further decrease in the
filtration activity. Despite
these possible interfering processes, we found statistically
significant difference between tests carried out with bivalves in
the pilot-plant and their respective controls for