unlocking waste to resource pathways for sustainable development

Abstract

Funding Information: This work was supported by the Research Unit on Applied Molecular Biosciences – UCIBIO (UIDP/04378/2020 and UIDB/04378/2020) and the Associate Laboratory Institute for Health and Bioeconomy - i4HB (LA/P/0140/202019), through national funds from FCT - Fundação para a Ciência e a Tecnologia, I.P. The authors acknowledge the Fundação para a Ciência e a Tecnologia (FCT) through the project PTDC/BTA-GES/2740/2020_NABIA, DOI 10.54499/PTDC/BTA-GES/2740/2020. The Coimbra Chemistry Centre (CQC) is supported by the FCT through the project UIDB/00313/2020, DOI 10.54499/UIDB/00313/2020. We are grateful for funding from PTScience which is supported through the programs CENTRO-05-4740-FSE-001526 and FEDER. Publisher Copyright: © 2025 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.The growing environmental crises demands an urgent transition from a linear to a circular economy. Microalgae are photosynthetic microorganisms that offer exceptional potential due to their rapid growth, high CO₂ fixation capacity, and ability to remove nutrients and pollutants from wastewater, producing both clean water and valuable biomass. Such characteristics have attracted interest in developing circular systems that transform wastes into resources such as biomaterials, biofertilisers, biofuels and bioactive compounds. However, various challenges hinder their industrial application, including technical, economic, environmental, commercial and political barriers. Technical limitations such as inefficient culture systems, low productivity and contamination risks, can be addressed by using genetic engineering tools to develop superior strains, and by developing bioreactors coupled with emerging technologies (AI, Digital Twin). Additionally, it was found that studies using wastewater for microalgae cultivation and a biorefinery approach to recover low and high value bioproducts were found to be energetically, environmentally and economically viable. Several projects and studies demonstrating microalgae-based circular economy models were highlighted. Finally, the implementation of clear regulations and guidelines for wastewater composition in microalgae systems is recommended to facilitate market acceptance and consumer trust in microalgae-derived products.publishersversionpublishe