Revealing the synergistic effects of cells, pigments, and light spectra on light transfer during microalgae growth: A comprehensive light attenuation model

[Display omitted] •Light attenuation model considering pigments and light spectra was established.•Attenuation of blue light was the most serious, followed by red and green light.•Total carotenoids contributed the most to the absorption of blue and green light.•Chlorophyll a played a major role in absorbing red light, which contributed 75.33%. As the sole energy for photosynthesis, light decrease rapidly with path due to absorption by pigments and scattering by cells in microalgal suspensions. By comprehensively considering cell concentrations, pigment components, and light spectra, a modified Cornet model for light transmission in microalgal suspensions is established. The developed model better fits experimental data with a higher adjusted R2, which is 5% higher than the model that is based only on cell concentration. The attenuation of blue light is the most severe, followed by red and green light. Among the three main pigments, total carotenoids contribute the most to the absorption of blue and green light (with contribution coefficients of 89.26 ± 4.53% and 46.04 ± 3.77%, respectively), and chlorophyll a contributes the most to the absorption of red light (with a contribution coefficient of 75.33 ± 5.08%). This study provides a better understanding and prediction of light transmission during microalgal cultivation.