Strengthening mass transfer of carbon dioxide microbubbles dissolver in a horizontal tubular photo-bioreactor for improving microalgae growth.

•A CO2 microbubbles dissolver promoted dissolving carbon in a photo-bioreactor.•The influence of pump power was more obvious than that of gas flow rate.•Ceramic shell aerator was more effective at increasing mass transfer coefficient.•Biomass yield was increased by 30% with ceramic shell aerator in dissolver.