2019_EJRNL_PP_STEFANO_MAGNI_1.pdf
Terbatas Lili Sawaludin Mulyadi
» ITB
Terbatas Lili Sawaludin Mulyadi
» ITB
The emerged threat of microplastics (MPs) in aquatic ecosystems is posing a new challenges in environmental
management, in particular the civil Wastewater Treatment Plants (WWTPs) which can act both as collectors of
MPs from anthropic use and as a source to natural environments. In this study, MP fate was investigated in
one of the biggest WWTPs of Northern Italy, built at the beginning of the 2000s and which serves a population
equivalent of about 1,200,000, by evaluating their presence at the inlet (IN), the removal efficiency after the settler (SET) and at the outlet (OUT), and their transfer to sludge. Samples were collected in three days of a week and
plastic debris was characterized in terms of shape, size and polymer composition using the Fourier Transform Infrared Microscope System (?FT-IR). The number of detected MPs was 2.5 ± 0.3 MPs/L in the IN, 0.9 ± 0.3 MPs/L
after the SET and 0.4 ± 0.1 MPs/L in the OUT, indicating a total removal efficiency of 84%. However, considering
that thisWWTP treats about 400,000,000 L wastewaters/day, the potential release of MPs to the receiving aquatic
system would be approximately 160,000,000 MPs/day, mainly polyesters (35%) and polyamide (17%). Furthermore, a great amount of MPs removed from wastewater was detected in the recycled activated sludge, with
113 ± 57 MPs/g sludge dry weight, corresponding to about 3,400,000,000 MPs deposited in the 30 tons of sludge
daily produced by this WWTP. Given the possible re-use of WWTP sludge in fertilizers for agriculture, our results
highlight that WWTPs could represent a potential source of MPs also to agroecosystems.