Filamentous Green Algae for Wastewater Treatment and Heavy Metal Bioremediation: A PRISMA-Based Bibliometric Review

<ns5:p> Filamentous green algae have gained increasing attention as biological agents for wastewater treatment due to their fibrous thalli, large surface area, and chemically active cell walls. These characteristics enable filamentous green algae to effectively support metal binding, nutrient uptake, and pollutant removal. This review synthesizes Scopus-indexed literature on the application of filamentous green algae in wastewater treatment and heavy-metal bioremediation, utilizing a PRISMA-based screening methodology alongside bibliometric mapping. The analysis focuses on studies involving <ns5:italic>Spirogyra, Cladophora, Oedogonium, Rhizoclonium</ns5:italic> , and other related filamentous green algae. A total of 328 unique records were identified in the Scopus database. Automated screening identified 161 studies as directly relevant, while 167 required manual assessment due to insufficient metadata. A bibliometric analysis using VOSviewer identified China, India, Australia, the United States, Pakistan, Turkey, and Poland as the leading contributors to this research area. Keyword co-occurrence mapping revealed that algae, green algae, bioremediation, biomass, bioaccumulation, Cladophora, wastewater treatment, adsorption, biosorption, and heavy metals form the core conceptual framework of the literature. These findings suggest that filamentous green algae offer significant potential as cost-effective, resource-oriented materials for wastewater treatment. However, further research is required to establish robust evidence regarding long-term operational stability, biomass regeneration, process scale-up, and integration with established wastewater treatment systems. </ns5:p>