A pilot-scale treatment method was used in the present study to test the biosorption of textile dye from textile effluent and carbon dioxide using Chlorella vulgaris RDS03. The textile dye effluent treatment achieved that textile dye biosorption capacity (q<inf>max</inf>) rate of 98.84% on 15 days of treatment using Chlorella vulgaris RDS03. The Langmuir and Freundlich isotherm kinetics model indicated that the higher R2 value 0.98. The microalga Chlorella vulgaris RDS03 was captured-96.86% of CO<inf>2</inf> analyzed by CO<inf>2</inf> utilization and biofixation kinetics, 4.65 mgmL−1 of biomass, 189.26 mgg−1 of carbohydrate, 233.89 mgg−1 of lipid, 4.3 mLg−1 of bioethanol and 4.9 mLg−1 of biodiesel produced. We performed fatty acid methyl ester (FAME) profiling using gas chromatography-mass spectrometry (GCMS). We found 40 types of biodiesel compounds, specifically myristic acid, pentadecanoic acid, octadecanoic acid, palmitic acid, and oleic acid. The high-performance liquid chromatography (HPLC) validated and analyzed the produced bioethanol. Novelty of the Research • Unicellular microalga Chlorella vulgaris RDS03 was isolated from the freshwater region and investigated their biosorption efficiency against hazardous synthetic azo textile dyes. • Chlorella vulgaris RDS03 ability to biosorption 96.86% of environmental polluted carbon dioxide • Treated biomass was used to produce ecofriendly, unpolluted and green energy such as biofuels (biodiesel and bioethanol). © 2023 Elsevier B.V., All rights reserved.