ADVANCEMENTS IN TECHNOLOGIES FOR AIR POLLUTION MITIGATION

Аннотация

Air pollution from volatile organic compounds (VOCs) and particulate matter (PM2.5) presents a complex environmental challenge shaped by multiple pollutants. Despite concerted efforts in the last twenty years, air quality continues to pose serious risks to both human health and environmental stability. Exposure to VOCs and PM2.5 indoors can lead to significant health issues, including respiratory illnesses, leukemia, birth defects, and miscarriages. Therefore, advancing indoor air purification technologies is essential to reduce these harmful effects. This article examines the latest trends, innovations, and potential future developments in indoor air purification methods. Keywords: VOCs, PM2.5, adsorption, metal-organic frameworks, photocatalytic oxidation, catalysts, additives Introduction. Air pollution due to CO2 emissions and particulate matter (PM2.5) is a multifaceted ecological challenge influenced by various pollutants. Particulate matter, categorized as PM10 or PM2.5, poses serious health risks associated with air pollution. Short-term exposure to elevated levels can worsen asthma and other respiratory conditions, impair lung function, and even lead to premature mortality. These particles can result from both direct emissions and the atmospheric transformation of precursor gases like NOx, sulfur dioxide (SO2), and ammonia, which also have detrimental effects on plants and human health. Adsorbent Materials Traditional adsorbent materials vary in composition and effectiveness for adsorbing pollutants from industrial emissions, largely influenced by their chemical properties and the concentration of pollutants. Activated carbon is recognized as one of the most effective adsorbents, though it can be relatively expensive [1]. Zeolite molecular sieves, 174 ACADEMIC RESEARCH IN MODERN SCIENCE International scientific-online conference another significant adsorbent, are inorganic crystalline materials characterized by a regular porous structure, strong acidity, and high hydrothermal stability, making them valuable in environmental remediation [2]. Biochar-based adsorption of volatile organic compounds (VOCs) operates through unique mechanisms, including adsorption in the carbonized phase and partitioning in the non-carbonized organic matter [3]. Biochars from different feedstocks show considerable variations in surface area, morphology, and elemental ratios like H/C and O/C, even under similar pyrolysis conditions. For instance, biochar derived from bamboo may achieve a specific surface area of 375 m²/g at 600 °C, while biochar from switchgrass might only reach 15 m²/g [4]. Table 1 presents data on 15 different types of biocoals used for VOC gas adsorption. Among these, acetone has the highest adsorption capacity at 483.09 mg/g, while benzene and toluene have capacities of 161.42 mg/g and 424.4 mg/g, respectively [5]. Table 1. Sorption Capacities of Various Biocoals for VOC Gases. Adsorbate Formula Weight Adsorption Source capacity Acetone C3H6O 58.08 483.09 [3] Acetone C3H6O 58.08 343.89 [3] Benzene C6H6 78.11 27.5 [4] Benzene C6H6 78.11 161.42 [5] Butanol C4H9OH 74.12 262.38 [6] Cyclohexane C6H12 84.16 327.18 [6] Ethyl acetate C4H8O2 88.11 420.92 [7] Ethyl acetate C4H8O2 88.11 450.24 [5] Isopropyl C5H10O2 102.13 147.45 [7] acetate Isopropyl C5H10O2 116.16 151.71 [7] acetate Toluene C7H8 92.14 366.72 [4] Toluene C7H8 92.14 424.4 [3] Methanol has the lowest adsorption capacity among VOC gases, measuring just 10.6 mg/g. The adsorption rate is mainly determined by the surface area of the biochar and its non-carbonized organic components. Increasing the temperature during biomass processing does not notably enhance VOC removal efficiency 175 ACADEMIC RESEARCH IN MODERN SCIENCE International scientific-online conference with biochar. Due to its cost-effectiveness and widespread availability, biochar serves as a practical adsorbent for VOCs. Additionally, incorporating nanoparticles with activated carbon improves the effectiveness of formaldehyde removal from the gas emission [6]. Reducing emissions through Metal-Organic Frameworks (MOFs). Metal-Organic Frameworks (MOFs) are a new class of crystalline materials that leverage the advantages of both organic and inorganic components. These materials are composed of metal ions or clusters interconnected by organic linkers [7]. MOFs are characterized by their large surface areas, varied functionalities, and remarkable thermal stability, making them highly suitable for various applications, including gas storage, separation technologies, pollutant capture, and chemical degradation processes. To achieve uniform particle sizes in Metal-Organic Frameworks (MOFs), parameters such as electric field strength and the flow rate of the polymer solution during electrospinning can be optimized. This method facilitates the development of composite polymer filters using PAN, PS, and PVP, capitalizing on the high adsorption capacity of MOFs while ensuring the filters remain flexi