Tannery wastewater remediation potential of cyanobacteria and algae with nutrient recovery, ecological monitoring and biomass valorization: A circular economy

Tannery wastewater (TWW) is a complex effluent containing high concentrations of biological oxygen demand (BOD), chemical oxygen demand (COD), total dissolved solids (TDS), and toxic heavy metals, particularly chromium, making its management a serious environmental concern. Conventional treatment strategies are often inadequate, whereas microalgae-based remediation offers an eco-friendly and sustainable alternative by simultaneously reducing pollutants and generating biomass for Value-Added Products (VAP). In the present study, region-specific algal strains were isolated and evaluated for their growth performance, physiological responses, and pollutant removal efficiency under TWW conditions. Detailed analyses revealed significant reductions in BOD, COD, and TDS, along with effective sequestration of heavy metals, demonstrating the high tolerance and remediation potential of selected isolates. Moreover, the harvested algal biomass showed promise for VAP generation, strengthening the concept of a circular bioeconomy. The findings highlight the dual benefits of microalgae in TWW treatment and biomass valorization, underscoring their potential role in sustainable industrial effluent management.