Feasible tannery wastewater treatment in an open alkaline photobioreactor: exploring lipid accumulation and direct air CO2 capture

López Belón L.; González-Sánchez A.; Chambi C.; Montalvo Andía J.P. · Total Environment Advances (2026) · DOI: 10.1016/j.teadva.2026.200151

Resumen

Tannery wastewater poses significant environmental and technological challenges due to its high organic load, nutritional imbalance, and toxic compound content. This study evaluated the treatment of real tannery effluents using a native microalgal consortium (NMC) isolated from high-radiation wastewater lagoons (7094 W m−2 d−1) located at 2300 m above sea level, cultivated in an open high-rate algal pond (HRAP, 24.5 L) under uncontrolled environmental conditions. Two concentration levels (75% and 100%) were tested to assess the influence of the COD:N:P ratio on pollutant removal, CO2 fixation, and lipid accumulation. The 75% concentration, with an approximate COD:N:P ratio of 10.9:1:0.19, resulted in higher CO2 fixation rates (281 mg L−1 d−1), higher biomass productivity (153.3 mg L−1 d−1), and higher removal efficiencies of NH3-N, total phosphorus, COD, and BOD5 (100%, 100%, 92.8%, and 86.6%, respectively). In contrast, the 100% effluent induced higher lipid content (18.5%) under nitrogen-limited conditions. Phosphate supplementation promoted the biosynthesis of storage compounds. Unlike previous studies using synthetic media, this research demonstrates that modulating the COD:N:P ratio in real industrial effluents serves as an effective metabolic strategy to simultaneously optimize pollutant removal and bioproduct generation, even in fluctuating environmental scenarios.

Instituciones: Universidad Católica San Pablo