The emission of microplastics into nature poses a threat to aquatic and terrestrial ecosystems. Their penetration of the food chain presents a danger to human health as well. Wastewater treatment plants can be seen as the last barrier between microplastics and the environment. This review focuses on the impact of waste treatment plants in retaining microplastics. Studies show that no wastewater treatment method leads to a complete retention of microplastics, and so wastewater treatment plants themselves are viewed as point sources for the discharge of microplastics into the aquatic environment. Problems associated with the utilization of microplastic loaded sewage sludge are also discussed in the review. Journal of Water Resource and Protection found as micropellets in cosmetic formulations and in facial cleaners and body scrubs (median size of 0.2 -0.4 mm), as microspherules in toothpastes (2 -5 μm in size), as well as in scrubbers used for air-blasting surfaces to remove paints and rust [25] and as drilling fluids in oil and gas exploration. A newer application is their use in drug delivery systems [26] [27]. In addition, synthetic polymer containing microparticles can also be released by the degradation of materials. The release of microfibers as a result of the washing of textiles has been widely reported as a source of microplastics [28] [29] [30] [31] [32]. These synthetic fibers, released by washing machines, are transported to waste water treatment plants [29] [33], where a considerable amount of them pass through the different treatment stages into the effluents due to their smaller size and enter the aquatic environment. It is estimated that around 35% of microplastics reaching the ocean are from synthetic textiles [34].Inventories of microplastics entering the environment have been attempted by organizations in different countries. A breakdown of the sources of microplastics in Sweden has been provided by Magnusson [35], which is given in detail below as an example of typical microplastic streams in developed countries. There is microplastic emission from plastic production, sandblasting material, cosmetic products, pharmaceutical drugs, textiles, road material and coatings. Using a spill factor of 0.04%, which was also used by Sundt et al. [26] for the estimation of pellet loss from the Norwegian plastic production plants, K. Magnusson et al. [35] have calculated a direct micropellet emission of 298 tons per year. In addition to that, there is loss due to the handling of plastic pellets which is set at between 0.0005% and 0.01%, adding another 12 -235 tons of microplastics emitted into the environment. These numbers were modeled on emission factors proposed by Lassen et al. [36] for the Danish production industry. However, no actual measured numbers of emissions of microplastics during production exist.The use of microplastics (e.g. of urea formaldehyde resins) in abrasive products for sandblasting has been deemed to be limited, and the use of these materials in Swedish shipyards is strictly regulated...

No abstract

Microplastics, plastic pieces of ≤5 mm in size, are ubiquitous in ther environment and can be found in both terrestrial and aquatic ecosystems. This manuscript reviews the literature on the fate of microplastics in wastewater treatment and briefly highlights novel developments in the removal of microplastics from aqueous systems.

In order to find out whether any toothpastes commercially available in the United Arab Emirates (UAE) carry microplastic content in form of plastic microbeads, the filterable solid contents of 31 toothpastes from UAE markets and 2 toothpastes imported from Syria were analyzed. FT-IR studies of the solids revealed that the major solid components were hydrated silica and calcium carbonate, where the individual toothpaste product exhibited either one or the other as the dominant constituent. Titrimetric analysis of the alkalinity of the ash of the toothpastes was carried out. The solids, ashed at 600˚C were subjected to FT-IR and EDS (energy dispersive X-ray spectroscopic) analysis. The ash of some of the products was shown to have TiO 2 and Ca 3 (PO 4 ) 2 as minor components. Mostly organic dyes were used as colorants; however, iron oxide (Fe 2 O 3 ) was also found. Importantly, none of the toothpastes carried any solid microplastic particles. Only 3 toothpastes carried microbeads at all, which were made of either silica or microcrystalline cellulose. This finding indicates that toothpastes, at least in the UAE, are no longer a significant source of microplastic in the environment. The results were compared to a toothpaste bought through the internet with a formulation from 2014, which exhibited polythene microplastic at 1.31 ± 0.39 w% of the filterable solid content.

No abstract