Integrated Assessment Of Chlorella Vulgaris, Scenedesmus Obliquus, And Nostoc Muscorum For Efficient Algal-Based Sewage Remediation

Abstract

The increasing demand for sustainable wastewater treatment solutions has led to growing interest in algal-based remediation systems. This study investigates the efficacy of three microalgal species—Chlorella vulgaris, Scenedesmus obliquus, and Nostoc muscorum—in treating municipal sewage collected from Dibrugarh, Assam. Laboratory-scale batch reactors were inoculated with algal cultures and monitored over 14 days for biomass accumulation, nutrient removal, and changes in physicochemical parameters. Results showed significant pollutant reductions in algal-treated systems, with C. vulgaris achieving the highest removal efficiencies for COD (85.2%), BOD (89.6%), total nitrogen (78.5%), and total phosphorus (82.0%). Dissolved oxygen levels increased markedly, particularly in C. vulgaris treatments (from 1.2 mg/L to 7.8 mg/L), while pH rose due to active photosynthesis. Algal biomass growth was positively correlated with pollutant removal efficiency, confirming the potential of these organisms as bioagents in sewage remediation. Compared to the control, which showed minimal improvement, algal treatments demonstrated clear advantages in pollutant removal and ecological restoration. This study proposes a novel, eco-friendly approach for decentralised sewage management, emphasising algae as multifunctional agents in wastewater bioremediation and resource recovery.