Harnessing Microalgal Systems for Sustainable Pollution Management: Mechanisms, Innovations, Bioreactor Technologies, and Future Perspectives

Industrial, agricultural, and urban pollutants pose a significant threat to both ecological and human health. Traditional remediation methods are sometimes effective, but they are often limited by restrictive pricing, complex operational procedures, and high energy requirements. Additionally, these methods can generate secondary pollutants, thereby compromising their sustainability. Algal bioremediation, also known as phycoremediation, leverages the natural capabilities of microalgae and cyanobacteria for remediation of pollutants. It offers a sustainable and multifunctional option for removing and detoxifying various environmental pollutants, including heavy metals, nutrients, and emerging organic pollutants. This study explains the principles and mechanisms of algal biosorption, bioaccumulation, enzymatic degradation, and phycoremediation. It also highlights the combined roles of extracellular polymeric substances and algal-bacterial groups. Additionally, it examines the operational factors and bioreactor technologies involved, highlighting recent advancements in process improvement and the challenges associated with large-scale use. Real-world case studies demonstrate the ecological effectiveness and cost benefits of algal systems, showing success in removing pollutants, recovering resources, and integrating circular bioeconomy practices. Although the current factors include scale-up limitations, biofouling, and environmental inconsistency, the combination of genetic engineering, artificial intelligence-controlled, and intelligent bioreactor setups offers potential solutions to improving the algal bioremediation process. The findings of our study recommend the creation of policy frameworks, industrial partnerships, and research alliances to harness the full potential of algae-based remediation for environmental stewardship and sustainability.