A standard analytical approach and establishing criteria for microplastic concentrations in wastewater, drinking water and tap water

• Published in: The Science of the total environment 2023-11, Vol.899, p.165356-165356, Article 165356
• Main Authors: Sol, Daniel, Solís-Balbín, Carmen, Laca, Amanda, Laca, Adriana, Díaz, Mario
• Format: Article
• Language: English
• Subjects: Analytical methods; Drinking water; Microplastics; Tap water; Wastewater
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2023.165356

The ubiquitous presence of microplastics (MPs) in natural water bodies reflects the global issue regarding these micropollutants. The main problem of MPs lies on the difficulty of removing these particles from water during wastewater and drinking water treatments. The release of MPs to the environment in treated wastewater contributed to the dispersion of these micropollutants, which enhances the harmful effect of MPs on fauna and flora. In addition, their presence in tap water entails a potential risk to human health since MPs can be directly consumed. The first step is being able to quantify and characterise these microparticles accurately. In this work, a comprehensive analysis on the presence of MPs in wastewater, drinking water and tap water has been conducted with emphasis on sampling methods, pre-treatment, MP size and analytical methods. Based on literature data, a standard experimental procedure has been proposed with the objective of recommending a methodology that allows the homogenisation of MP analysis in water samples. Finally, reported MP concentrations for influents and effluents of drinking and wastewater treatment plants and tap water have been analysed, in terms of abundance, ranges and average values, and a tentative classification of different waters based on their MP concentrations is proposed. [Display omitted] •Sampling is key to avoid mistakes in the quantification of MPs from wastewater, drinking water and tap water.•There is no consensus on sample pre-treatment at international level to allow comparison of results.•The sensitivity of the analytical technique is critical in order to not underestimate MPs.•Tentative criteria to classify different kinds of waters according to MP pollution have been proposed.•Further investigation is needed in drinking water and more effective treatments for MP removal in WWTPs.