土器ストーブ排気からの総揮発性有機化合物（VOC）の低減に関する研究：産業廃棄物由来ナノファイバーシートの利用

Recent progress in indoor air emission control technologies remains largely economically inaccessible to low-income populations, where even basic necessities such as food, clean water, and health care are often unaffordable. The high price and maintenance cost of these technologies make their adoption impractical. Apart from financial barriers, many of these air emission reduction technologies are time-consuming. These technologies require a significant amount of time to effectively reduce a high concentration of pollutants, delaying immediate health benefits. This delay is particularly problematic in places that already suffer from acute pollution-related health issues. Traditional earthen stoves (chulhas) release exceptionally high concentrations of total volatile organic compounds during ignition, with the first 5 min posing the greatest toxic risk. In many Asian countries, women, who are primarily responsible for cooking and are often accompanied by infants and young children, experience the highest exposure during this critical period. This study presents an innovative, cost-effective, and time-efficient approach for mitigating total volatile organic compound emissions from earthen stoves (Chulhas) using electrospun nanofiber sheets fabricated with industrial waste fly ashspecifically lignite coal fly ash and bituminous coal fly ashincorporated into polyacrylonitrile. Electrospun nanofiber membranes were fabricated using different ratios of polyacrylonitrile to lignite coal fly ash and bituminous coal fly ash (17:1, 17:2, 17:3, and 17:4). The membranes containing lignite coal fly ash were labeled NF-01 to NF-04, while those with bituminous coal fly ash were labeled NF-05 to NF-08. This formulation made it possible to compare how different ash types and concentrations affected membrane adsorption performance. Among all the formulations, NF-04, incorporating lignite coal-derived fly ash, exhibited the highest total volatile organic compound removal efficiency of 59% within 5 min, highlighting its effectiveness for rapid and efficient pollutant capture. In contrast, NF-08, containing bituminous coal-derived fly ash, achieved a comparatively lower total volatile organic compounds removal efficiency of 18% within 5 min. In order to evaluate the surface morphology, surface area, identifying functional groups, confirming elemental composition, and then crystalline composition, the nanofiber sheets were subjected to physicochemical characterization using scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET), Fourier transform infrared spectroscopy (FTIR), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD), respectively. These analyses support the nanofiber relevancy for effective total volatile organic compound adsorption. Our developed nanofiber-based filtration methodology not only enables immediate mitigation of toxic pollutants but also serves as an innovative model for government-led interventions promoting clean energy adoption and indoor air quality improvement.