Strategies for biomass yield and pollutant removal improvement during Chlorella cultivation in explosive industry wastewater

Condori M.A.M.; Choque Y.S.T.; Quispe Lopez J.E.; Gutierrez M.E.V.; Assemany P. · Algal Research (2025) · DOI: 10.1016/j.algal.2025.104441

Resumen

This study evaluated different cultivation strategies to increase Chlorella sp. MC18 biomass production in explosive industry wastewater (EWW). Experiments varied light wavelengths (white, blue, and red) and CO2 exposure times (5–60 min) in real and synthetic wastewater. Red light did not show a positive effect, but white light with shorter CO2 exposure times (5–15 min) improved growth kinetics, while blue light showed better results with longer CO2 exposure times (20–60 min). Among these, optimal conditions in 1 L flasks were blue light with 45 min CO2 and white light with 10 min CO2, yielding higher dry biomass production (0.91 and 1.02 g L−1, respectively). Cultivation in a 4 L photobioreactor confirmed these results, achieving biomass productivity of 0.106 g L−1 d−1 for blue light and 0.135 g L−1 d−1 for white light. The microalgae demonstrated effective CO2 sequestration (average of 1.968 g L−1) with a high CO2 biofixation rate (0.238 g L−1 d−1 for white light with 10 min of CO2 exposure). The positive impact of CO2 in enhancing biomass production and nutrient removal efficiency (84–85 % for nitrate and 96–98 % for phosphate) during EWW cultivation was also confirmed. The produced biomass was rich in carbohydrates (46.08 %) under white light, and balanced in carbohydrates (34.87 %), lipids (28.21 %), and proteins (23.32 %) under blue light. This study demonstrates the potential for integrating microalgae biotechnology within the explosive industry, employing effective strategies for augmenting valuable biomass production, CO2 capture, and wastewater bioremediation.

Instituciones: Universidad Nacional de San Agustín de Arequipa