Research progress on microplastics in wastewater treatment plants: A holistic review

Biodegradable Microplastics in Municipal Wastewater and Sludge Treatment Processes: A Review on Occurrence, Fate, and Effects

“…51 Simultaneously, the unbonded plastic additives in BMPs like plasticizer and flame retardants will also be released. 52 The leaching of plastic additives and the accumulation of polymer chain scissions could further promote surface cracking and render the plastic more susceptible to bioaccumulation. 53 This series of processes is termed as aging.…”

“…14,15,76−78 The resulting water-soluble oligomers can be further assimilated through appropriate metabolic pathways (such as the Krebs cycle 79,80 ) as a source of carbon or nitrogen. 52,55 And the end products of BMPs were reported to be biomass, CO 2 , H 2 O, or CH 4 . 22 Hence, future research endeavors ought to focus on the abundance and activity of these enzymes during the processes of wastewater and sludge treatment, along with elucidating the mechanisms by which hydrolysis products are assimilated by microorganisms as carbon and nitrogen sources.…”

“…When exposed to environmental stress such as sunlight, high salinity, high alkalinity, and water shear force, BMPs will experience physiochemical transformations, causing the polymer backbone to break and smaller fragments to form (Figure ). Simultaneously, the unbonded plastic additives in BMPs like plasticizer and flame retardants will also be released . The leaching of plastic additives and the accumulation of polymer chain scissions could further promote surface cracking and render the plastic more susceptible to bioaccumulation .…”

Adding Depth to Microplastics

“…1−4 To date, concentrations and characteristics of microplastic particles in our living environment are mainly determined using spectroscopic techniques. 5,6 However, these techniques only provide information about the particles in two dimensions (2D), making it difficult to estimate properties that require all three dimensions (3D), such as particle volume, mass, and surface area. 7 It is precisely these 3D properties that are necessary to properly determine the transport, effects, and risks of MP.…”

“…Our ability to accurately measure concentrations of microplastic particles ( MP ) and their characteristics is a prerequisite for monitoring spatiotemporal trends and risks of these particles to human health and the environment. − To date, concentrations and characteristics of microplastic particles in our living environment are mainly determined using spectroscopic techniques. , However, these techniques only provide information about the particles in two dimensions (2D), making it difficult to estimate properties that require all three dimensions (3D), such as particle volume, mass, and surface area . It is precisely these 3D properties that are necessary to properly determine the transport, effects, and risks of MP . − For example, based on a growing body of evidence, recent risk assessments assume that the volume of particles ingested determines the risk posed by food dilution, whereas the risk of MP from translocation-mediated effect mechanisms is assumed to relate to the surface area of the particles. ,− Here, the toxicological implications do not relate to the volume and area of individual particles, but to the collective volume and area of the bioavailable mixtures of particles as they occur in the air we breathe, in our food and drinking water, and in nature. ,,, Techniques that directly measure the properties of 3D particles, such as Raman imaging or AFM, are currently too labor intensive to be a viable option in the field of MP studies.…”