Decontamination of Sewage Wastewater by an Aeration Method Utilizing Water Hardness-Reducing Spirulina platensis

This study investigates the potential of Spirulina platensis, a blue-green algae species, for the remediation of sewage wastewater, providing a sustainable approach to wastewater management. Over a 20-day period, with aeration at 3 L/min, Spirulina effectively reduced key pollutants, including chemical oxygen demand (COD), phosphate, nitrate, magnesium, and other impurities. Advanced analyses using FTIR, SEM, and EDX revealed that the primary mechanism of remediation was the adsorption of contaminants onto Spirulina. In addition, rapid photosynthetic growth under sunlight (200-400 μmol photons/m²/s) facilitated nutrient absorption while producing high-value biomass rich in proteins and essential nutrients. This dual-purpose approach not only purifies wastewater but also enables resource recovery, reducing the need for chemical fertilizers and promoting circular economy practices. Furthermore, the process contributes to carbon sequestration, offering a viable method to lower greenhouse gas emissions. The findings highlight Spirulina platensis as an eco-friendly, innovative solution with significant environmental and socio-economic benefits.