Cellulose-based sorbents are promising materials for wastewater treatment due to their environmental friendliness, biodegradability, and high sorption capacity. This paper presents an overview of cellulose modification methods, including carboxylation, amination, oxidation, graphene, and plasma treatments, as well as combined approaches. Their effect on key physicochemical properties, such as porosity, morphology, and chemical stability, is considered. Examples from the literature confirm the effectiveness of modified cellulose sorbents in removing heavy metal ions and organic pollutants from wastewater. The analysis shows that combined methods allow for creating materials with improved characteristics that are resistant to extreme operating conditions. The main advantages and disadvantages of cellulose sorbents, as well as challenges associated with their scalability and cost-effectiveness, are discussed. The paper emphasizes the importance of further research to advance these materials as a key element of sustainable water treatment technologies.

This article considers modern approaches to obtaining synthetic oil from unconventional hydrocarbon feedstocks, including plastic waste, tires, biomass, coal, and extra-heavy oil. Particular attention is paid to multi-stage technologies, such as pyrolysis, catalytic depolymerization, gasification followed by Fischer–Tropsch synthesis, and hydrocracking of heavy residues. The important role of catalysts in increasing the selectivity and economic efficiency of processes is noted: nanostructured, bifunctional, and pollution-resistant systems are increasingly used. Economic factors influencing the competitiveness of this industry are considered, including the volatility of prices for traditional oil, government support measures, and the development of waste logistics infrastructure. It is emphasized that the strengthening of the position of synthetic oil is associated with the growth of environmental requirements stimulating the recycling of plastics, tires, and biomass; at the same time, compliance with high environmental standards and transparency of emission control play a critical role in the social aspects of projects. In addition to improving the environmental situation, the development of synthetic oil contributes to the creation of jobs, the resolution of problems of shortage of classical oil fields, and the increase of energy security. It is concluded that further improvement of technologies and integration into industrial clusters can turn this sphere into a significant component of the future energy sector.

This study reports the solvent-free synthesis, structural characterization, and performance evaluation of poly (methyl methacrylate-co-acrylic acid) [P(MMA-AA)] copolymers intended for use as sustainable concrete primers and industrial coatings. A series of copolymers with varying MMA-AA molar ratios were synthesized via bulk radical polymerization and characterized using ¹H and ¹³C nuclear magnetic resonance (NMR) spectroscopy, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The resulting materials were evaluated for their physical mechanical properties, including viscosity, tensile strength, surface hardness, and wettability. The findings revealed that higher MMA content improved the thermal stability, tensile strength, and hardness of the coatings, whereas increasing the AA content enhanced crosslinking density, hydrophilicity, and chemical resistance. These results demonstrate the potential of solvent-free P(MMA-AA) copolymers as environmentally friendly, high-performance alternatives to conventional solvent-based systems in protective coating applications.

Waste-derived natural polymers offer a route to low-cost sorbents for toxic metal ions, but reported performance is difficult to compare because precursor composition, polymer processing, modification, and experimental conditions vary widely. This critical review examines silk fibroin, banana peel, orange peel, and pectin as structurally distinct platforms and evaluates how macromolecular chemistry, esterification, ionic crosslinking, morphology, and regeneration influence metal uptake. Particular attention is given to the distinction between untreated biomass, isolated biopolymers, and chemically engineered materials; to mechanistic evidence from spectroscopy, elemental analysis, ion exchange, and controlled structural modification; and to the limitations of interpreting Langmuir or pseudo-second order fitting as direct proof of adsorption mechanism. The literature supports strong roles for pectic carboxyl groups and Ca²⁺-mediated exchange in several cation-binding systems, while silk fibroin provides a reusable protein-based matrix with different donor-site chemistry. Across the four platforms, high q_max values are not transferable material constants and do not by themselves establish selectivity, practical treatment performance, or analytical sensitivity. Major gaps include precursor standardization, matched comparison of raw and modified sorbents, multicomponent and real-water testing, nonlinear model evaluation, continuous-flow studies, regeneration stability, metal recovery, and end-of-life management. Diffuse-reflectance sensing is considered as a downstream value-added function once a reproducible biosorbent has been established. An evidence-based roadmap is proposed for converting polymer-rich wastes into controlled, regenerable, and application-oriented biosorbents.

Effect of flocculants and electrolytes on the stability of kaolin hydrosuspension