Cyanobacteria-Based Bioremediation and Biomass Recovery from Agro-Industrial Wastewater

Cyanobacteria offer a sustainable and cost-effective approach to wastewater bioremediation due to their adaptability and nutrient removal efficiency. This study assessed the performance of Synechocystis sp., Synechococcus sp., and Oscillatoria sp. in treating agro-industrial wastewater, while evaluating the potential of such wastewater as a growth medium for large-scale cyanobacterial biomass production. Two wastewater sources, agricultural runoff water (AROW) and poultry meat processing effluent, were tested at 25% and 50% dilutions under controlled laboratory conditions for 14 days. Growth (OD₆₈₀) and changes in physicochemical parameters (pH, EC, TDS, DO, BOD, COD, NO₃⁻, PO₄³⁻) were monitored. All strains achieved biomass yields comparable to the synthetic BG-11 medium, with Synechocystis sp. showing the highest growth in 25% AROW. Significant pollutant reductions (70–90%, p  < 0.05) were recorded across treatments; notably, Synechocystis sp. and Oscillatoria sp. removed up to 95% and 98% of NO₃⁻ and PO₄³⁻, respectively, in 25% wastewater. This is the first report demonstrating that diluted AROW can outperform synthetic media for certain cyanobacterial strains, combining effective nutrient removal with low-cost biomass production potential. These findings highlight the dual utility of agro-industrial wastewater as both a treatment target and a cultivation resource, with implications for scalable, resource-efficient bioprocesses.