Different light wavelengths effect on AD

In this study, the objective was to explore the impact of different wavelengths on light-assisted anaerobic digestion (AD) under ammonia stress. To simulate the diverse wavelengths within the visible solar spectrum, the energy-efficient light-emitting diodes (LEDs) were utilized as a light source. Specifically, this study involved: (1) comparing the performance of AD at short, medium, long, and full visible wavelengths; (2) examining the structure and properties of mixed consortia characterized by various light colors; and (3) delving into the mechanism on the wavelength-regulated metabolic pathways and syntrophic association. To the best of our knowledge, this is the first study to elucidate the light-stimulating mechanism via metagenomic analysis of microbial profiles and metabolic routes. The obtained results could provide insight into the internal changes in light-assisted anaerobic bioprocesses from academic point, and further contribute to guiding the practical engineering of a solar-integrated bioprocess for the treatment of ammonia-rich feedstock.