Synergistic bioremediation of agro-industrial wastewater by microalgae and activated sludge for biofertilizer production: influence of photoperiod and inoculation ratio

Monzón Martínez L.; Chambi Mamani C.; Rendón Merino A.; González-Sánchez A.; Montalvo Andia J. · Environmental Technology (United Kingdom) (2025) · DOI: 10.1080/09593330.2025.2534199

Resumen

This study investigates the potential of a synergistic co-culture of microalgae (M) and activated sludge (AS) for the bioremediation of agro-industrial wastewater and the valorization of resulting biomass for biofertilizer production. Co-cultures were established with inoculation ratios of 1:1, 1:3, 1:0, and 0:1 (M:AS) and cultivated under two photoperiod regimes (24L:0D and 16L:8D) for 14 days. The highest removal efficiencies were observed in the 1:1 and 1:3 treatments under the 24L:0D regime, achieving up to 90.61% COD, 100% nitrogen, and 99.8% phosphorus removal. Biomass analysis revealed substantial macromolecular content, including lipids (24.2% and 16.2%), proteins (39.5% and 43.2%), and carbohydrates (70.8% and 53.7%) under 24L:0D and 16L:8D, respectively. The biofertilizer potential of the biomass was assessed using Cucumis sativus seeds, showing improved germination and growth, particularly at 25% dilution, with a 90% germination index, an average of 4 ± 0 leaves, and shoot length of 5.05 ± 2.07 cm. These findings highlight the dual benefit of pollutant removal and biomass valorization in integrated wastewater management.

Instituciones: Universidad Católica San Pablo