Emerging Water Pollutants and Wastewater Treatments
21
Size is one of the major parameters for categorizing materials into macro and
nanoscale. It is the fragmentation of larger plastics that led to the formation of micro
and nanoplastics. Recent studies have shown that macro plastics are those with size
greater than five millimeters (>5 mm), microplastics have a size range between one
micro meter (1 μm) to five millimeters (5 mm), while nanoplastics have sizes less
than one micro meter (0.1 μm). Nanoplastics are therefore defined as the product
of polymer fragmentation that exhibits colloidal properties with the size range from
between 1 and approximately (1 μm = 1000 nm) [61, 62]. Both nanoparticles (NPs)
and nanoplastics (NaPs) derive their sources through several anthropogenic activities.
They enter the water body via primary and secondary routes. The primary routes, as
well as primary NaPs, are concerned with the intentionally produced products, such
as pharmaceutical products, paints, and personal care products like cosmetics. On the
other hand, secondary routes, as well as secondary NaPs, refer to the source that has
to do with the degradation and fragmentation of larger particles. They successfully
enter the water body by improper and unselective disposal of waste disintegrated by
natural agents, such as the sun, waves and winds. Generally, both NPs and NaPs are
released during production, uses and guided or unguided disposal of NPs containing
products [48, 63–65].
NPs find relevance in environmental remediation and structuring of environmental sensors for pollutant detection [37, 66, 67], drug delivery and antibacterial
applications [55, 68], engineering electronics and nanocrystalline materials [69, 70]
energy generation from photoelectrochemical applications [71], and in mechanical
industries for the building of coating, lubricant, and adhesives [55, 72, 73].
Despite the vast applications of NPs, their toxicity arising from their usage is
hazardous to the water body. Figure 4 presents various routes of nanoplastics into the
water environment. Similarly, NaPs toxicity arising from the post-consumer indiscriminate waste disposal has been reported. As earlier established, discharges of
NaPs can be launched from microplastic and macroplastic because of fragmentation
and degradation. Direct emission from merchandise and applications consists of electronics, magnetics, optoelectronics, waterborne paints, biomedical products, adhesives, coatings, and 3D—printing [74]. Both NPs and NaPs cause gastrointestinal
disorders, liver, reproductive and neurotoxicity when they are ingested by human
or aquatic organisms [75, 76]. They have the capacity to blend with heavy metals,
polyaromatic hydrocarbon (PAH), and polychlorinated biphenyl (PCBs). NaPs have
the capacity to transport contaminant. Using molecular simulation, [77], investigated nano-sized polystyrene reporting cellular functions could be affected when
nano-sized polystyrene pervades into the lipid membranes. Bioaccumulation of NPs
and NaPs affects plants, vertebrates and invertebrate aquatic organisms. It also alters
the life cycles of bacteria and microbes [77–80].
21
Size is one of the major parameters for categorizing materials into macro and
nanoscale. It is the fragmentation of larger plastics that led to the formation of micro
and nanoplastics. Recent studies have shown that macro plastics are those with size
greater than five millimeters (>5 mm), microplastics have a size range between one
micro meter (1 μm) to five millimeters (5 mm), while nanoplastics have sizes less
than one micro meter (0.1 μm). Nanoplastics are therefore defined as the product
of polymer fragmentation that exhibits colloidal properties with the size range from
between 1 and approximately (1 μm = 1000 nm) [61, 62]. Both nanoparticles (NPs)
and nanoplastics (NaPs) derive their sources through several anthropogenic activities.
They enter the water body via primary and secondary routes. The primary routes, as
well as primary NaPs, are concerned with the intentionally produced products, such
as pharmaceutical products, paints, and personal care products like cosmetics. On the
other hand, secondary routes, as well as secondary NaPs, refer to the source that has
to do with the degradation and fragmentation of larger particles. They successfully
enter the water body by improper and unselective disposal of waste disintegrated by
natural agents, such as the sun, waves and winds. Generally, both NPs and NaPs are
released during production, uses and guided or unguided disposal of NPs containing
products [48, 63–65].
NPs find relevance in environmental remediation and structuring of environmental sensors for pollutant detection [37, 66, 67], drug delivery and antibacterial
applications [55, 68], engineering electronics and nanocrystalline materials [69, 70]
energy generation from photoelectrochemical applications [71], and in mechanical
industries for the building of coating, lubricant, and adhesives [55, 72, 73].
Despite the vast applications of NPs, their toxicity arising from their usage is
hazardous to the water body. Figure 4 presents various routes of nanoplastics into the
water environment. Similarly, NaPs toxicity arising from the post-consumer indiscriminate waste disposal has been reported. As earlier established, discharges of
NaPs can be launched from microplastic and macroplastic because of fragmentation
and degradation. Direct emission from merchandise and applications consists of electronics, magnetics, optoelectronics, waterborne paints, biomedical products, adhesives, coatings, and 3D—printing [74]. Both NPs and NaPs cause gastrointestinal
disorders, liver, reproductive and neurotoxicity when they are ingested by human
or aquatic organisms [75, 76]. They have the capacity to blend with heavy metals,
polyaromatic hydrocarbon (PAH), and polychlorinated biphenyl (PCBs). NaPs have
the capacity to transport contaminant. Using molecular simulation, [77], investigated nano-sized polystyrene reporting cellular functions could be affected when
nano-sized polystyrene pervades into the lipid membranes. Bioaccumulation of NPs
and NaPs affects plants, vertebrates and invertebrate aquatic organisms. It also alters
the life cycles of bacteria and microbes [77–80].