Identification of microplastics in conventional drinking water treatment plants in Tehran, Iran

Abstract

The presence of microplastics (MPs), as an emerging pollutant is a growing concern in different water resources. These particles are recognized as less than 5 mm in size. Most of the studies have been carried out in surface waters and wastewater treatment plants (WWTPs), but there are few studies on MPs in drinking water treatment plants (DWTPs). This study investigates these particles in three different conventional DWTPs in the city of Tehran, Iran and aims to analyze these particles down to the size of 1 µm. A scanning electron microscope (SEM) was utilized in this study to quantitatively analyze MPs. Accordingly, the average abundance of MPs in raw and treated water samples varied from 1996±268 to 2808±80 MPs L -1 and 971±103 to 1401±86 MPs L -1 , respectively. While particles smaller than 10 µm comprised 65-87% of MPs. Moreover, µ-Raman spectroscopy was used to characterize MPs. As the results, polypropylene (PP), polyethylene terephthalate (PET), and polyethylene (PE) were the most abundant identi ed polymers among MPs comprising more than 53% of particles. Additionally, MPs were categorized as bers, fragments and spheres. This study lls the knowledge gap of MPs presence in Tehran DWTPs which is of high importance since they supply drinking water for more than 8 million people and investigates the performance of conventional DWTPs in removing MPs.

It matters how we measure - Quantification of microplastics in drinking water by μFTIR and μRaman

“…Comparing the outcomes of the two methods, it is evident that the usage of only μFTIR would have led to a ∼150 times underestimation of the MP counts abundance in the analysed drinking water. Accordingly, μRaman was shown to provide higher MP abundance values in drinking water, in accordance with studies conducted in the Czech Republic [ 40 ] (up to 3605 N/L in raw water and 628 N/L in treated water), China [ 41 ] (440 N/L on average in tap water from 38 cities), and Iran [ 42 ] (up to 2808 N/L in raw water and 1401 N/L in treated water).…”

Do Drinking Water Plants Retain Microplastics? An Exploratory Study Using Raman Micro-Spectroscopy

“…The findings confirmed the common observation that there tend to be more small MPs than large ones, for example [47,48], who also employed μRaman in their studies. Ref.…”

Microplastics in water, from treatment process to drinking water: analytical methods and potential health effects

“…[41] ; Zhang et al [21] ; Eerkes-Medrano et al [25] ; Hohmann-Jedd [42] References and number in bold indicate those reviews that cover altogether more than one topic of the table and thus are repeated.…”