Microalgae for Wastewater Treatment and Resource Recovery: Pathways to a Circular Bioeconomy

Microalgae offer a promising, nature-based approach to treating wastewater while recovering valuable resources from waste streams. Through photosynthesis and nutrient assimilation, microalgae can remove organic matter, heavy metals, and emerging pollutants while contributing to carbon capture. The resulting biomass can be converted into biofuels, biofertilizers, animal feed ingredients, biostimulants, pigments, and other high-value bioproducts. By linking pollution control with resource recovery, microalgal systems support circular bioeconomy models that reduce waste, lower environmental impacts, and create new value from municipal, agricultural, and industrial effluents. Continued advances in cultivation systems, algal-bacterial consortia, harvesting methods, and life cycle assessment are helping move microalgae-based wastewater treatment toward scalable and sustainable implementation. Microalgae for Wastewater Treatment and Resource Recovery: Pathways to a Circular Bioeconomy explores how microalgae can be used to treat wastewater while recovering valuable resources. It highlights pathways for integrating microalgal technologies into circular bioeconomy systems that reduce pollution, support sustainability, and create value from waste streams. Covering topics such as algal-bacterial interactions, life cycle analysis, and wastewater valorization, this book is an excellent resource for environmental scientists, wastewater treatment professionals, bioprocess engineers, environmental engineers, biotechnology researchers, and more.

Imran Ahmad is a dedicated researcher, academic, and scientific consultant deeply committed to environmental sustainability and algae biotechnology. With an MPhil and PhD from Universiti Teknologi Malaysia, his expertise lies in biological wastewater treatment, microalgal bioremediation, and resource recovery. His work bridges research and application, focusing on innovative solutions that address environmental challenges while contributing to the principles of a circular bioeconomy. He has been actively involved in designing and optimizing photobioreactors, anaerobic reactors, and microalgae-based treatment systems that offer sustainable alternatives for wastewater management and carbon sequestration. He works as a Scientific Consultant and Bioprocess Engineer with ProAlgaeTech, a startup focused on microalgal carbon sequestration and wastewater bioremediation. His contributions extend beyond academic research, as he engages in industrial applications that translate scientific advancements into real-world impact. He has been integral to international projects, including the Indo-European Horizon 2020 PAVITR project and Liquid Trees, where his insights have helped shape strategies for efficient wastewater treatment and bioenergy production. He also obtained a utility innovation for a modified grease trap design for restaurant wastewater, further demonstrating his ability to develop practical engineering solutions. His research has yielded numerous high-impact publications, reflecting his dedication to advancing knowledge in environmental engineering. His work has been recognized at both national and international levels. He has received the My Membrane Award from the Malaysia Membrane Society, UTM, and has been acknowledged by Japan's Algae Industry Incubation Consortium. He was also nominated as the Secretary of the International Conference on Environmental Science and Green Technology in 2022. Alongside his research contributions, he has spent more than eight years in academia, mentoring students, designing laboratory infrastructure, and fostering interdisciplinary collaborations. His experience in teaching and research has allowed him to contribute to shaping the future of environmental engineering education. Beyond his professional achievements, he remains committed to developing sustainable technologies that bring about meaningful change. His work is driven by the conviction that scientific research should yield practical, lasting solutions that benefit both the environment and society. Whether through academia, consultancy, or industry partnerships, he continues exploring ways to integrate innovation with sustainability, ensuring that his contributions have a lasting impact on green technology.

Faizal Bux , Director of the Institute for Water and Wastewater Technology (IWWT,) DUT has ~28 years of experience in the field water and wastewater treatment technology. His focus research areas include wastewater technology, algal biotechnology and bioenergy production. Prof Bux has also assumed the position of NRF SARChI (South African Research Chair Initiative) Chair from 2018. As a NRF B rated researcher and Academy of Science of South Africa (ASSAf) member, he has supervised 64 Masters and Doctoral students, hosted 23 PDF’s and received numerous institutional awards. The Water Research Commission has been awarded Prof Bux the ‘Knowledge Tree Award for Transformation and Redress’ for his impact in growing PDI involvement in 2017. More recently, Prof Bux received the 2018 National Research Foundation (NRF) award, “Champion of Research Capacity Development and Transformation at South African Higher Education Institutions”. He has acted/current editor for CLEAN Soil Air Water (John Wiley & sons, Germany), Environmental Science and Health Part A (Taylor Francis, USA), Biofuels Research Journal and Water Science and Technology and as a reviewer for >50 ISI Journals. He has contributed to 148 journal articles, 18 book chapters and >150 conference presentations and led 11 WRC projects. His citations are in excess of 5000 with an H Index of 33. Prof Bux currently holds the positions of the National coordinator and Chair of International Thematic Group (ITG): Water Resource and Pollution Research of the BRICS Networks University. In 2018 Prof Bux was nominated as Chair of the ITG BRICS-NU for 2 years with the option of a second term. He served 2 terms as a Member of IWA Management Committee specialist group Microbial Ecology and Water Engineering (MEWE) and on the Executive committee of IWA-SA as Treasurer. He was been elected as a member of the Academy of Science of South Africa in 2016. Prof Bux was admitted as a Fellow of the Water Institute of Southern Africa, Royal Society of Chemistry and more recently International Water Association. He has served on the scientific program committee/Advisory board/Chair/Invited speaker of various national and International conferences and holds memberships to many professional bodies. He has an extensive network of university collaborators globally and served as scientific advisor to NGOs both locally & internationally. He has been involved in bilateral projects with India, Brazil, Egypt, China, Algeria with continuing collaboration. He currently has bilateral projects with Japan, Oman, Poland (subject to approval) and global projects involving Oklahoma University (USA) and Aalborg University (Denmark). He has played a key role in assisting the University to increase its research capacity and contribute to the Human Resource Capital Development of the country.

Nilamjyoti Kalita is an Assistant Professor & Head of the Department of Botany at Murkong Selek College, Assam, India. He earned his Ph.D. from Gauhati University, focusing on heavy metal remediation using cyanobacterial strains from oil-contaminated sites of Upper Assam. A university topper in his M.Sc. in Botany, he has strong expertise in molecular biology, algal taxonomy, and stress physiology. Dr. Kalita has published extensively in reputable Q1 international journals such as Journal of Hazardous Materials Advances, Food Biosciences, Journal of Polymers and the Environment, Heliyon, Plant Physiology and Biochemistry, Microbiological Research, etc., and has contributed to several Springer Nature-edited volumes. His research emphasizes the application of cyanobacteria and microalgae in bioremediation and sustainable technologies. He is a recipient of the Dr. Deba Kumar Bordoloi Memorial Young Scientist Award (2026) from the Botanical Society of Assam.