###### Abstract  
Microplastics (MPs), and specifically microfibres (MPFs), are ubiquitous in water bodies, including wastewater and drinking water. In this work, a thorough literature review on the occurrence and removal of MPs, and specifically MPFs in WWTPs and DWTPs, has been carried out. When the water is treated, an average microfiber removal efficiency over 70% is achieved in WWTPs and DWTPs. These high percentages are still inefficient for avoiding the presence of a large number of microfibres in treated wastewater and also in tap water. RSF, DAF, oxidation ditch and CAS processes have been described as the most efficient treatments for eliminating MPFs from wastewater treatment. It is remarkable the wide range of the data reported on this topic; for example, treated wastewater contains between not detected and 347 MPFs/L, whereas tap water contains between not detected and 168 MPFs/L. Microfibres constitute more than half of the MPs found in treated wastewater and sewage sludge, whereas in DWTP effluents the percentage of MPFs is around 32%. Nevertheless, the relative amount of MPFs reported in tap water is notably higher (71%). Microfibres from WWTPs are discharged to the environment, being a source of MP pollution. Additionally, MPs released by DWTPs directly enter the drinking water lines, which constitute a direct route for MP human consumption, so that it has been estimated that an adult may ingest an average value of 7500 MPFs per year only via tap water. Thus, this review provides an update on the performance of WWTPs and DWTPs in removing MPs from water, which is an issue of great interest.  
microfibres; technologies; removal; WWTPs; DWTPs; tap water +
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contact also have to be considered [34]. Specifically, the presence of these microparticles in the atmosphere increase their entry into the human body by 74,000-121,000 MPs per year [33]. Moreover, it has been suggested that nanoplastics could cross the epidermal barrier, although it is not the major entry route of these particles [35]. The potential risk of MPs is enhanced by their hydrophobic character; thus, they have the capacity to adsorb chemical additives and toxic pollutants, such as metals, PCBs, pesticides, etc., on their surface [36; 37; 38; 34].  
In order to reduce the dispersion of microfibres and other MPs in the environment, wastewater treatment plants (WWTPs) and drinking water treatment plants (DWTPs) should be considered as hotspots in which to tackle this environmental problem (Figure 1).  
In this work, a review on the current status of the occurrence and removal of MPs in WWTPs and DWTPs was carried out. The incidence of MPs, especially microfibres, and the performance of treatment processes to reduce the presence of MPs in treated wastewater and drinking water was analysed. For wastewater from WWTPs a total of 67 studies from 23 countries were reviewed (Table 1), whereas for sludge 41 studies from 19 countries were evaluated (Table 2). In the case of DWTPs and tap water, a total of 9 studies from 6 countries and 11 studies from 20 countries, respectively, were considered (Tables 3 and 4). The vast majority of studies were carried out in Europe (48%) and Asia (43%); in particular, most of them were conducted in China (approximately 27% of the total studies reviewed).