The problem of the excessive CO₂ emitted into the atmosphere is one of the significant problems for the modern world and ecology. This article examines the dynamics of carbon dioxide absorption from thermal power plants, TPP, and waste gases by three types of microalgae, the most typical for the Russian Federation: Chlorella kessleri, Chlorella vulgaris, and Chlorella sorokiniana. The exhaust gases of the TPP contain up to 39% carbon dioxide. In this work, the rate of absorption of carbon dioxide from model exhaust gases with a CO₂ content of up to 39% was studied. As a result of the study, a species of microalgae (Chlorella vulgaris) was identified, characterized by the maximum rate of absorption of CO₂ = 0.412 g/L·day and the maximum volume of CO₂ utilized in 1 day = 8.125 L. The conducted research proved the possibility of utilizing a large content (up to 39%) of carbon dioxide from the exhaust gases of the TPP with the help of microalgae of the genus Chlorella. A scheme for the utilization of CO₂ with the help of microalgae is also proposed, which meets the principles of a circular economy (closed cycle).

This article explores the feasibility of producing biohydrogen from microalgae following their use in wastewater purification from food industry facilities and the removal of high levels of carbon dioxide (CO₂) from the air. The authors investigated various methods for disrupting the cell membranes of microalgae and their impact on biohydrogen yield. The microalgae biomass obtained after wastewater and air purification underwent pre-treatment using physicochemical and chemical methods, including microwave radiation, acid treatment, and thermal treatment. The highest hydrogen production occurred during thermal and acid treatments of biomass with the addition of starch (44.24 mL/L of suspension). The use of microwave radiation for processing did not yield significant results. A comparison of the biohydrogen values obtained from untreated and treated biomass revealed that treatment enhances biohydrogen yield.

This article concerns the effect of the chemical modification of short flax fiber on its sorption properties for heavy metal ions. The main purpose of the modification was to achieve the oxidation of flax cellulose with sodium metaperiodate to form dialdehyde cellulose. Additionally, the research shows the subsequent interaction of dialdehyde cellulose with 1-amino-8-hydroxynaphthalene-3,6-disulfonic acid and its transformation into a derivative capable of forming chelate complexes with heavy metal ions. Additionally, this article presents the results of equilibrium and kinetics studies of the sorption of Cu(II), Cd(II), and Fe(II) ions from aqueous solutions by primary and modified cellulose sorbents. SEM spectra indicate changes in the surface structure of the modified sorbents compared to the original one. IR spectra show the appearance of amino- and sulfogroups in short flax fibers in the process of their modification. The research revealed the efficiency of the method and the possibility of its use for the purification of aqueous solutions from heavy metal ions in industrial processes.

The aim of the work was to investigate the prospects of imparting valuable physical and chemical properties, such as corrosion resistance, impact and bending strength, adhesion and storage stability, to hybrid systems of potassium and sodium silicates by modification with organic compounds. Here, we present the results of worldwide activities of scientific teams studying the manufacturing technology of modified liquid glass anticorrosive coatings used in chemical, petrochemical industry and modern construction. The authors theoretically and economically justified and put into practice novel organic and inorganic compositions with increased viability. The durable and waterproof coatings with good adhesion to various substrates (non-ferrous metals, steel, plastered surface and wood) were obtained. The authors demonstrate the possibility of recycling of zinc-containing rongalite production wastes and sludge pastes of electrochemical productions containing alkali and alkaline-earth metal cations by including them into the composition instead of pigmenting solid-phase components. We propose a technological route for obtaining anticorrosion coatings to protect aluminum and its alloys operated in a zone of elevated (up to 673 K) temperatures.

This article presents an analytical review of current research on the biofixation of TPP emissions with microalgae. Microalgae are considered as promising microorganisms for carbon dioxide capture, the specific properties of CHP flue gases as a culture medium are characterized, and the influence of key process conditions, including CO2 concentration, illumination, temperature, pH, nutrient availability, and gas feed mode, is analyzed. Data on the use of various types of photobioreactors and flue gas feed schemes are summarized. It is shown that the efficiency of CO2biofixation depends significantly on the biological properties of the cultures used, as well as on the gas composition, the depth of its pretreatment, the design of the photobioreactor, and the chosen method for evaluating the results. Based on a comparison of literature data, it was established that the most promising candidates for biofixation of TPP emissions are members of the genera Chlorella, Scenedesmus, and Desmodesmus. Particular attention is given to the processing of the resulting biomass, primarily the production of feedstock for bioenergy and biofertilizers. It is concluded that further development of the technology involves selecting resistant strains, improving photobioreactors, optimizing cultivation modes, and transitioning to long-term pilot testing on real flue gases from power plants.