Review on Algal Biomass as a Sustainable Resource: Bioactive Compounds, Extraction Technologies, and Multifunctional Applications

The intensifying global challenges of environmental degradation, escalating energy demands, and unsustainable waste accumulation necessitate the exploration of alternative, high-value biomass resources. Algal biomass has emerged as a uniquely versatile and sustainable candidate, offering transformative potential across a broad range of industrial and environmental sectors. This review comprehensively evaluates the recent advancements and multidisciplinary applications of algae, with a strong emphasis on their distinctive chemical composition, bioactive compounds, and environmental adaptability. The novelty of this review lies in its integrative scope, which spans from algae cultivation, production, and trade to cutting-edge extraction technologies for bioactive constituents. Furthermore, the review presents a detailed exploration of algae’s functionality as a feedstock for biofuels, pharmaceuticals, sustainable agriculture, bioplastics, green chemistry, and water treatment, positioning it as a cornerstone in the development of the blue economy. By critically analyzing both conventional and innovative applications, this work contributes to a deeper understanding of algae’s strategic role in shaping a sustainable and resilient bioeconomy.