Microplastics (MPs) and nanoplastics (NPs), formed as a result of plastic product degradation, pose a global environmental threat by penetrating biological systems and inducing systemic pathological changes. This systematic review, conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews guidelines, aims to analyze the molecular and cellular mechanisms of the toxic effects of MPs and NPs on the human cardiovascular, nervous, reproductive, urinary, and digestive systems. The primary mechanisms include oxidative stress, inflammation, mitochondrial dysfunction, apoptosis, autophagy, ferroptosis, and impaired barrier functions. In the cardiovascular system, MPs and NPs contribute to endothelial dysfunction, disorders of lipid metabolism, and fibrosis; in the nervous system, they promote neuroinflammation, pathological protein aggregation, and psychiatric disorders; in the reproductive system, they lead to hormonal imbalance and reduced fertility; in the kidneys, they cause inflammation, and fibrosis and lead to deterioration of kidney function; and in the gastrointestinal tract, they contribute to dysbiosis and metabolic disorders. The literature search was conducted in the PubMed, Web of Science, and Scopus databases without limitations on date, language, or access. Studies were selected based on criteria of transparency, statistical validity, sample representativeness, and correctness of data interpretation. The review emphasizes the necessity of an interdisciplinary approach to developing prevention and treatment strategies, including reduction in exposure, antioxidant and immunomodulatory therapy, and restoration of barrier functions and microbiota. The data obtained reveal research gaps and identify directions for further study.

One of the main strategies for improving the efficiency of agricultural production is the use of fertilisers with slow or controlled release of nutrients, in which the granules of mineral fertilisers are covered with polymeric shells. The composition of the polymer coatings of mineral fertiliser granules with slow or controlled release of two widespread manufacturers and their ability to adsorb some heavy metal ions on their surface were examined in this study. It was found that the base polymers used to encapsulate the fertilisers studied are the co-polymer polyethylene–polyacrylic acid in the Brand A, and polyacrylamide, polyacrylic acid, and its esters in the Brand B fertiliser coating. The maximum adsorption rate of heavy metal ions on the surface of the polymer coatings with the rest of the mineral filler of Brand A and Brand B fertilisers was 54.64 and 28.90 mg/g for Cd(II) ions, 30.77 and 14.03 mg/g for Pb(II) ions, respectively. Therefore, the solution to the problem of increasing the efficiency of agricultural production through the use of fertilisers with slow or controlled release of nutrients leads to environmental pollution by microplastics remaining in the soil after fertiliser application, which are also capable of adsorbing from the soil various toxic pollutants.

Model spherical polystyrene particles are studied to understand the interactions of microplastics with organic pollutants. Analysis of the experimental results presented in the literature is complicated since researchers use different types and concentrations of particles, durations of tests, etc. In addition, there is little information on the effect of the structure of the surface layer of polystyrene particles on the processes under study, and the question of the effect of the shape of polystyrene particles remains open. Here, we present the first results of a model experiment to study the effect of the shape and structure of the surface layer of polystyrene microspheres and non-spherical particles of 2 to 5 μm in size on the sorption properties in relation to model molecules of rhodamine B as a model organic pollutant. The properties of both the initial model polystyrene particles and the modified ones were studied by optical, transmission electron, and atomic force microscopy, as well as using the Brunauer–Emmett–Teller method (BET). The sorption process was studied by spectrophotometry, and the analysis of sorption curves was carried out using the Langmuir model. It is shown that the shape of polystyrene model particles does not have a significant effect on the sorption capacity. At the same time, the sorption processes of rhodamine B molecules are determined by the structure of the surface layer, which can be changed, for example, by exposing the polystyrene microspheres to N,N′-dimethylformamide.

Comprehensive wastewater treatment from various pollutants is an urgent problem, and the development of new sorbents is of great scientific and practical importance. Sorbents based on sapropel were obtained: thermally oxidized sapropel, humic acids isolated from sapropel, thermally oxidized sapropel modified with humic acids, organomineral composite material based on thermally oxidized sapropel and bentonite. Resorcinol adsorption from model solutions with concentrations from 1 · 10-5 to 1 · 10-2mol/dm3 onsapropel-based sorbents was carried out under static conditions at a ratio of 1 g of sorbent per 200 cm3 of solution. It is shown that the limiting stage of resorcinol adsorption onsapropel-based sorbents is mixed diffusion. The adsorption theories of Langmuir, Freundlich, Brunauer–Emmett–Teller (BET) and Dubinin–Radradkevich are applicable to describe the resorcinol adsorption onsapropel-based sorbents. Taking into account the values of the activation energy and thermodynamic parameters of resorcinol adsorption, the obtained sapropel-based sorbents can be considered as the mechanism of resorcinol adsorption on the surface and physical adsorption due to volumetric filling of micro- and mesopores, as well as cavities. Resorcinol can also form covalent and hydrogen bonds with silicate and aluminosilicate groups, and hydrogen bonds with amino groups with sapropel-based sorbents. Therefore, it is quite difficult to separate the contribution of physical adsorption and possible chemical interactions of functional groups of sapropel-based sorbents with resorcinol. Limiting values of resorcinol adsorption onsapropel-based sorbents calculated by the BET equation (0.25–1.00 mmol/ g) and the Dubinin–Radushkevich equation (0.52–2.60 mmol/g), comparable to other developed sorbents.

The adsorption of solutions of petroleum products with concentrations from 10 to 150 mg/dm3, phenols with concentrations from 0.01 to 1.0 mmol/dm3 and heavy metals with concentrations from 0.1 to 100 mmol/dm3 was studied. Sapropel, heat-treated at 600 оC in an oxidizing medium (TOS), was used as a sorbent. The assessment was carried out under static conditions at 1 g of sorbent per 200 cm 3 of solution. Processing of experimental data according to the Boyd and Morris-Weber kinetic models showed that copper(II) ions adsorption by TOS has a mixed-diffusion character. The dependence of the copper(II) ions adsorption by TOS on the contact time is satisfactorily described by both Lagergren and Ho and McKay kinetic models. The thermodynamic values of the adsorption of copper(II) ions from a model solution by TOS were calculated using Ho and McKay kinetic model, taking into account the chemical interaction between the copper(II) ion and the functional groups of the adsorbent. However, it is quite difficult to determine the proportion of chemical interaction and diffusion based on formal kinetic equations. It was established that resorcinol adsorption is described by the Dubinin-Radushkevich equation, while the oil products and copper(II) ions adsorption is described by the Brunauer-Emmett-Teller polymolecular adsorption equation (BET). The calculated quantitative characteristics of resorcinol, copper(II) ions and oil products adsorption by TOS showed that TOS can be used as a sorbent for wastewater treatment from oil products, phenols and heavy metals.

One of the methods of detoxification of aerobically stabilized sludge of biological treatment plants from heavy metals is a chemical method based on shifting the equilibrium of reversible metal binding processes by compounds of aerobically stabilized sludge with the introduction of poorly soluble calcium compounds. It was found that about 35% of copper(II), lead(II), cobalt(II), and nickel(II) interact with organic substances that make up the aerobically stabilized sludge by the complexation mechanism, 25% are co-precipitate on Fe2O3, MnO2, CaCO3, MgCO3, and about 25% is co-precipitated by the mechanism of isomorphic substitution on silicates and aluminosilicates. About 55% of chromium(III) is co-precipitated with Fe2O3, MnO2, CaCO3, MgCO3 by adsorption and occlusion mechanisms, about 28% is co-precipitated with silicates and aluminosilicates by isomorphous substitution mechanism, and about 8% is bound with organic substances by the complexation mechanism. The maximum recovery of metals from aerobically stabilized sludge (50–65%) is achieved by using poorly soluble calcium compounds in doses of 25 g/dm3. At introduction of insufficiently soluble calcium compounds the metals bound to compounds of aerobically stabilized sludge by mechanisms of physical and ion exchange adsorption are extracted, a significant proportion of metals co-precipitated with iron(III) and manganese(IV) oxides, with calcium and magnesium carbonates by the mechanisms of adsorption and occlusion, and bound to organic compounds by complexation mechanism. Metals forming chelated complexes with aromatic compounds and metals coprecipitated on silicates and aluminosilicates by the mechanism of isomorphic substitution are not extracted in contact with the injected materials, regardless of their nature. After detoxification of the sludge, the indicators for copper, lead, nickel and chromium (mg/kg of dry matter) do not exceed the established standards for sludge (GOST R 54534-2011 and GOST R 54651-2011), allowed for use as fertilizers and soils for biological remediation of disturbed lands.