Effect of biological and chemical oxidation on the removal of estrogenic compounds (NP and BPA) from wastewater: an integrated assessment procedure

A major source of the wide presence of EDCs (Endocrine Disrupting Compounds) in water
bodies is represented by direct/indirect discharge of sewage. Recent scientific literature
reports data about their trace concentration in water, sediments and aquatic organisms, as
well as removal efficiencies of different wastewater treatment schemes. Despite the
availability of a huge amount of data, some doubts still persist due to the difficulty in
evaluating synergistic effects of trace pollutants in complex matrices. In this paper, an
integrated assessment procedure was used, based on chemical and biological analyses, in
order to compare the performance of two full scale biological wastewater treatment plants
(either equipped with conventional settling tanks or with an ultrafiltration membrane unit)
and tertiary ozonation (pilot scale).
Nonylphenol and bisphenol A were chosen as model EDCs, together with the parent
compounds mono- and di-ethoxylated nonylphenol (quantified by means of GCeMS).
Water estrogenic activity was evaluated by applying the human breast cancer MCF-7 based
reporter gene assay. Process parameters (e.g., sludge age, temperature) and conventional
pollutants (e.g., COD, suspended solids) were also measured during monitoring campaigns.
Conventional activated sludge achieved satisfactory removal of both analytes and
estrogenicity. A further reduction of biological activity was exerted by MBR (Membrane
Biological Reactor) as well as ozonation; the latter contributed also to decrease EDC
concentrations.