Primary and secondary | China (Beijing) | 681.46 μm | 95.16 | Microscopy and FT-IR | Yang et al., 2019 [121] |
Primary, secondary and tertiary | Italy (Italy) | 0.5 - 0.1 mm | 113,000a | FT-IR | Magni et al., 2019 [115] |
Secondary | Australia (New South Wales, Hunter Region) | >1.5 μm to >1 mm | 7.91 ± 0.44 MP/L (in activated sludge | Visual sorting and ATR-FT-IR | Raju et al., 2020 [144] |
Primary and secondary | Italy | <1 mm | 1.67 MP/g TS in the Sludge, 5.3 MP/g TS in the AerWAS and 4.74 MP/g TS dewatered sludge | Stereomicroscope and µ FT-IR | Pittura et al., 2021 [142] |
Primary and secondary | Spain (Valencia) | <1 mm | 280 MP/Lof activated sludge | μ-ATR-FT-IR/ATR-FT-IR | Alvim et al., 2020 [140] |
Primary and secondary | Iran (Bandar Abbas City) | >250 µm | 328.50 (±56.42, SD) MP/50 g dw and 278.4 (±26.87, SD) MP/50 g dw | SEM and X-ray EDX | Naji et al., 2021 [133] |
Primary and secondary | Spain | 25 to 104 µm | 183 ± 84 MP/g (mixed sludge), 165 ± 37 MP/g (dried sludge) | Visual inspection and FT-IR | Edo et al, 2020 [109] |