A comprehensive bio-composition investigation of microalgal species is essential for categorizing their applications. In this study, nutrients uptake followed by complete biomass characterizations, including proximate, ultimate, and bio-compounds (proteins, carbohydrates, and lipids), were performed along with FTIR and TGA/DTG, analyses of four microalgal strains (Tetradesmus dimorphus GEEL-06, Tetradesmus obliquus GEEL-07, Chlorella sp. GEEL08, and Chlorella sorokiniana GEEL-09). All microalgae species were able to remove 90%-95% nitrogen and phosphorus. T. dimorphus GEEL-06 had highest growth with proteins accumulation of 36.63% and 28.33% of lipids. T. obliquus GEEL-07, Chlorella sp. GEEL08, and C. sorokiniana GEEL-09 accumulated 46.37%, 31.13%, and 39.38% of proteins and 27.94%, 34.61%, and 36.56% of carbohydrates, respectively. FTIR spectra revealed the presence of an alcohol, carboxyl, and amino groups, while biomass pyrolysis showed 67%-80% decomposition. Biodiesel feasibility was confirmed by the presence of 68%-84% C16/C18. These results indicate the potential applications of T. obliquus GEEL-07, C. sorokiniana GEEL-09, and T. dimorphus GEEL-06/Chlorella sp. GEEL08 for production of higher alcohols, bioethanol, biodiesel/oil for, respectively, along with nutrients removal. (C) 2020 Elsevier Ltd. All rights reserved.