In a groundbreaking study, researchers have developed an innovative biochar-based material for air treatment, marking a significant advancement in the removal of particulate matter and volatile organic compounds (VOCs) in indoor environments. Utilizing diatoms-enriched microalgae biochar, this first-of-its-kind material showcases remarkable efficiency in scrubbing harmful pollutants such as total volatile organic carbons (TVOCs) and formaldehyde (HCHO), achieving removal rates of approximately 99%. The biochar, cultivated from waste anaerobic digestate and pyrolyzed at various temperatures, displayed a significant increase in specific surface area—up to 482 m² g⁻¹—compared to conventional biochars, owing to the mesoporous structure of diatom frustules.

This research emerges in response to the pressing need for effective solutions to indoor air pollution, exacerbated by high levels of particulate matter and VOCs, especially in densely populated areas like Delhi, India. Traditional air filtration methods, often reliant on non-biodegradable materials, fall short in addressing high VOC concentrations and pose environmental risks due to disposal challenges. The novel microalgal biochar offers a sustainable alternative, leveraging the natural adsorption capabilities of microalgae and the structural advantages of diatoms to create a highly efficient, reusable filter material.

Significantly, the study not only highlights the superior pollutant removal efficiency of the developed biochar over existing commercial filters but also illustrates a sustainable and circular approach to indoor air treatment. By utilizing microalgae, which require minimal land for cultivation and can thrive in wastewater, the research promotes a low-impact, environmentally friendly method for improving air quality. This innovative use of biochar derived from microalgae represents a pivotal step toward addressing global air pollution challenges, emphasizing the role of advanced materials in creating healthier indoor environments.