Performance of different microalgae-based technologies for integral biogas slurry nutrient removal and biogas upgrading in response to various 5-deoxystrigol concentrations.

This study compared the performance of three microalgae-based techniques, namely, microalgae monoculture, microalgae co-culture with activated sludge, and microalgae-Ganoderma lucidum S395-2 endophytic bacteria co-culture, for concurrent biogas slurry purification and biogas upgrading. Effects of microalgae species, algae treatment technologies, and exogenous addition of 5-deoxystrigol (5-DS) on strains growth and photosynthesis within different microalgae-based treatment technology systems, as well as the purification effects were studied. Microalgae co-cultured with G. lucidum-bacterium significantly improved the photosynthetic capacity, biomass, nutrient removal efficiency, and biogas conversion rate. The Tetradesmus obliquus-G. lucidum-bacterium consortium with 5-DS at 10-11 M exhibited highest purification efficiency, with the a removal of 87.63 ± 8.51% chemical oxygen demand (COD), 89.76 ± 8.49% total nitrogen and 88.62 ± 8.53% total phosphorus from the biogas slurry and the removal of CO2 in the biogas was 76.59 ± 7.36%. [ABSTRACT FROM AUTHOR]