Non-negligible aldehydes in the environment: Emerging challenges and advanced removal strategies

Aldehydes, a class of reactive volatile organic compounds (VOCs), are pervasive environmental pollutants emitted from diverse sources, including industrial activities, building materials, and natural processes. Among them, certain aldehydes with established toxicity profiles exhibit environmental persistence and broad distribution. Chronic exposure to these specific compounds at elevated concentrations, particularly in occupational settings or heavily contaminated environments, has been linked in epidemiological and toxicological research to an increased risk of adverse health outcomes. To address these challenges posed by aldehydes, a range of remediation strategies specifically targeting this class of compounds has been developed, encompassing physical (e.g., adsorption, membrane separation), chemical (e.g., photocatalysis, thermal catalytic oxidation), and biological (e.g., plant/microbial remediation) approaches. This comprehensive review critically evaluates current aldehyde-focused removal technologies, with the primary goals of optimizing existing aldehyde-targeted methodologies and guiding the development of novel, cost-effective strategies that balance removal efficiency with environmental sustainability, ultimately aiming to mitigate the ecological and health impacts specifically associated with aldehyde pollution.