Table 1.

Summary of studies in which microplastics were identified in STP influents and effluents.

Location	Information of STP		Sampling method			Analytical Method			Number concentrationa		Ref.
	Daily process capacity (×103 m3 d-1)	Population Equivalent (×1,000)	Sampling equipment	Sample volume (L)		Pretreatment	Analytical equipment	Size cut-off (mm)	Influent (MP L-1)	Effluent (MP L-1)
				Influent	Effluent
Scotland	261	650	Steel buckets (10 L)	30	50	filter (11 μm)	dissection microscope & FT-IR	11	15.7 ± 5.23	0.25 ± 0.04	[38]
			Steel sieve (65 μm)
Sweden		14	Plankton net (mesh size; 300 μm)	2	1,000		stereo microscope & FT-IR	300	15.1 ± 1.54	0.0082 ± 0.0017	[44]
			Suction pump
USA			Steel sieve (400, 180, 45 μm)		189,000-232,000		microscope & FT-IR	45		0	[27]
Germany	0.52-35	7-210	Moble pumping device (10 μm stainless steel filter)		390-1,000	EMb	micro FT-IR	10		0-0.05d	[43]
						WPOc				0.01-9e
Netherland			Glass jar	2	2	filter (0.7 μm)	light microscopy & FT-IR	0.7	73 ± 13	65 ± 67	[32]
USA	189	680	Steel sieve (5, 1, 0.355, 0.125 mm)			WPO	dissection microscope & micro FT-IR	125			[42]
Finland		310-800	Pump-filter device (200, 100, 20 μm)	0.3	30-285		stereo microscope	20	610	13.5 ± 2.9	[35]
Finland	270	800	Pump-filter device (300, 100, 20 μm)	0.1e	1,000e		stereo microscope & FT-IR	20	568f ± 165	2.5f ± 1.5	[37]
				0.1f	10.5-13.5f				640g ± 255	0.6g ± 0.2
Australia	13-308	67-1,227	Stainless steel sieve (500, 190, 100, 25 μm)		3-200	WPO	dissection microscope & FT-IR	25		0.21-1.5	[31]
USA	2.3-382	3.5-56,000	Tyler sieves (355, 125 μm)		4,847	WPO	dissection microscope	125		0.05 ± 0.024	[33]
USA	2.3-310		Stainless steel sieve (355, 125 μm)			WPO	dissection microscope	125		0.022-0.13	[45]
Finland	10		Stainless steel bucket sieve (0.25, 5 mm)	4-30		WPO	optical microscope & FT-IR	250	57.6 ± 32.8	1 ± 1.1	[46]
France	240		Automatic sampler			filter (1.6 μm)	stereomicroscope	100	293	35	[47]
Finland	14-88		Pump-filter device (300, 100, 20 μm)				stereomicroscope & FT-IR	20		0.04-1.2	[36]
Canada			ISCO peristaltic pump 100 μm nylon mesh		100	WPO	stereomicroscope	100		0.07	[48]

^amean value±standard deviation;

^benzymatic maceration;

^cwet peroxide oxidation;

^dMP size>500 mm;

^eMP size<500 mm;

^fgrab sampling;

^g24-h composite sampling.