Advanced oxidation treatment methods for microplastic removal from wastewater.

AOP	MP targeted	Monitoring methods	AOP performance	Other parameters	Ref.
C,N–TiO2 photocatalysis	Polyethylene (PE) beads	Mass loss, FTIR measured carbonyl index (CI), microscopy	50 h, mass loss 72% and large increase in CI	Visible light LED (400–800 nm), temperature 0–40 °C, pH 3–11, lamp distance 25 cm, 4 L−1 MPs, 4 g L−1 catalyst (optimum removal at pH 3, 0 °C)	219
N–TiO2 photocatalysis	PE beads and flakes	Mass loss, CI	50 h, mass loss < 5% for all (4.6% HDPE and 1.8% LDPE)	Visible light LED (400–800 nm), pH 3, room temperature, 4 g L−1 MPs, lamp distance 21.5 cm	220
ZnO nanorod photocatalysis	PE film	Microscopy (SEM), mechanical change, CI	175 h, CI increase of 30%	Visible light 50 W dichroic halogen ambient air. Deionised water	224
N–TiO2 photocatalysis	PE beads	Mass loss, SEM, CI	8 h, mass loss < 3% in aqueous solution	27 W visible fluorescent lamp (400–800 nm), room temperature, lamp distance 12 cm, 2 g L−1 MPs	223
PMS/carbon nanospring photocatalysis	PE	Mass loss, CI, SEM	8 h, 40% mass loss	pH 3–11, MPs 5–12 g L−1, temperature 25–160 °C (>150 °C optimum)	227
ZnO photocatalyst supported on glass fibre	Polypropylene (PP)	Size change, CI, SEM	456 h, 65% reduction in volume	Visible light 60 mW cm2, 300 mL min−1 continuous flow treatment of 104 particles per L	225
TiO2 nanoparticle photocatalyst film	Polystyrene (PS)	Diameter change, DRIFTS, GC-MS	24 h required for removal of 400 nm starting diameter particles	254 nm UV irradiation	221
ZnO nanorod photocatalysis with Pt modification	PE film	CI, SEM	175 h	Visible light 50 W, room temperature, lamp distance 10 cm	222
TiO2	Polyamide (PA) fibre	Mass loss, CI, total organic carbon (TOC), SEM	48 h, 94% mass loss	UVA irradiation, room temperature, 5 lamp photo reactor	226
Modified TiO2 photocatalysis	Poly(methyl methacrylate) (PMMA), PS	TOC	7 h, flow reactor	UVA irradiation 112 W m2	229
Hydroxy-rich ultrathin BiOCl photocatalysis	PE	Mass loss	5 h, 6% mass loss	250 W of 420 nm irradiation; MP and catalyst 1 g L−1	228
Photo-Fenton	PS	SEM, CI, HPLC/MS, contact angle, C : O atomic ratio (XPS)	108 h, CI increase	500 W mercury lamp, 12 g L−1 MPs	231
Fenton	PS and high density PE	Size distribution, CI, C : O ratio by XPS	1–30 days	pH 4, 3 mM Fe, 4.5 mg mL−1 H2O2	232
Fenton	PE, PP, polyvinyl chloride (PVC), nylon	Microscopy	10 min, minor surface area decrease	Room temperature, pH 5, 7 g L−1 MPs, 3–10 mg mL−1 Fe	233
Thermal Fenton	PE, PS, PP and polyethylene terephthalate (PET)	Mass loss, CI, DSC to determine crystallinity, XRD, SEM, Raman spectroscopy, particle sizing by zetasizer	16 h, 96% mass loss	4 mM Fe2+, 300 mM H2O2	234
Heterogeneous photo Fenton/photocatalysis	PP, PVC	FTIR, particle diameter by microscopy	7 days, 94–96% size reduction	Nano zero valent iron and combined with ZnO/SnOx photocatalysis, 60 mW cm2 visible light	235
Ozonation	PE	FTIR, XPS	60–180 min, increase in CI	Ozone 4–7 mg L−1	236
Ozonation	Mixed MPs obtained from real wastewater	Particle counting	99.2% removal after tertiary treatment (this includes removal via other methods during the treatment process)	Ozone 12.6 mg L−1 for 1 min during tertiary treatment	237
Ozonation, H2O2/ozone	PE, PP, PS	Adsorption, XRD, SEM, FTIR	10 min, ozone dose of 88 mg L−1	O3 : H2O2 molar ratio of 0.5	238