Table 1.

A summary of MP purification techniques.

MP Purification Technologies	MPs Used	Size	Removal Efficiency	Advantages	Limitations	Ref
Filtration	Wastewater, surface water	100–5000 µm	88.1%	Efficient mix of sorption-biological treatment processes Low maintenance costs Simple operation	Act as secondary MP sources Disability to treat small-sized MPs Sludge aggregation Mechanical devices	[7]
	wastewater	20 μm–4.75 mm	97.2%			[6]
	PES, PET, PA, PE, PP	<5 mm	99.3%			[8]
Biological degradation	PE	250–1000 μm	43%	Simplicity and safety for large-scale use Low operating costs Practically applicable in different environments Flexibility to handle a wide range of wastewater characteristics and flows	Aggregation of microbial assemblages on the surface Environmental conditions cannot be easily controlled Difficulty in the analysis of products on a large scale Lack of reproducibility Difficulty in finding the suitable microbial community	[9]
	PE, PP, PET, PS	75 μm	1.6–7.4%			[10]
Electro coagulation	PE	-	>90%	No chance of secondary pollution Suitable for the removal of smallest particles Sludge minimization Energy efficiency Cost-effectiveness Flexibility for automation	Repeated need for replacing the sacrificial anode, cathode passivation Non-usable in areas without electricity	[15]
Chemical coagulation	PE	<5 mm	<90.9%	Suitable for the removal of small microparticles Controllable operational conditions Use of simple mechanical devices	Addition of chemicals to media Non-usable for large MPs	[43]
	PE, PS	180 nm–125 μm	<13.6%			[52]
	PET, PE, PP, PAM	1–100 μm	40.5–54.5%			[53]
Extraction	PP, PE, PTFE, PET	5–100 µm	67–77%	No need for using oil Treatment of large volumes of water Can be used without further infrastructure High speed	No report on waste management Can only be used for extracting MPs from binary mixtures	[16]
	PS, PE, PET, PVC	10–5000 µm	93%			[18]
	PS, seawater	100–200 nm	95.5%			[54]

MP—microplastic; PES—polyethersulfone, PET—polyethylene terephthalate; PA—polyamide, PE—polyethylene; PP—polypropylene; PS—polystyrene; PAM—polyacrylamide; PTFE—polytetrafluoroethylene, PVC—polyvinyl chloride.