<p>Dumping of untreated industrial wastewater into natural waterbodies and land has become a significant issue in the past few decades and is only increasing. This study evaluates and compares the efficiency of three widely utilized wastewater treatment methods—Coagulation-Flocculation, Ozonation and Sequencing Batch Reactor—for treating hospital and pharmaceutical industrial effluents to develop a solution that is economically and technically manageable. The raw wastewater samples were characterized by multiple physicochemical parameters. Coagulation-flocculation, used different combinations of Polyaluminum chloride, Polyacrylamide, alum and BWD-01, achieving almost 99.6% turbidity reduction and incase of heavy metals 91.2% of Cd and 89.8% of Cu were removed, but Chemical Oxygen Demand removal was inconsistent and almost ineffective. Ozonation resulted in 96% chemical oxygen demand removal, dissolved oxygen levels improved significantly reducing turbidity and alkalinity. Heavy metal showed varying degrees of reduction. Sequencing Batch Reactor showed highest turbidity removal (99.8%) and 79.4% chemical oxygen demand removal, and 99% reduction in alkalinity. Lastly, full-scale treatment plants and detailed cost estimation were developed to evaluate scalability for each method. After comparing all the results ozonation emerged as the most cost-effective and low-maintenance option for long-term operation for any industry. This study concludes that ozonation treatment offers a balanced solution in terms/m of both performance and feasibility in a resource-constrained settings. These findings can be useful for any industry while selecting and implementing efficient, scalable wastewater treatment plant to ensure regulatory compliance and environmental sustainability.</p> Graphical abstract <p></p>