Visible-light-drivenself-floating Ag2MoO4/TACN@LF photocatalyst inactivation of Microcystis aeruginosa: Performance and mechanisms

The poor light transmittance, low recycling rate and potential secondary pollution problems of powder photocatalysts limit the practical application of photocatalytic technology. Therefore, there is an urgent need to develop stable floating photocatalysts to alleviate the problem of harmful algal blooms (HABs). In this work, a floating Ag2MoO4/TACN@LF composite was synthesized for the inactivation of Microcystis aeruginosa (M. aeruginosa) by employing a simple oscillatory impregnation method. The Ag2MoO4/TACN@LF floating photocatalyst exhibited stable algae removal performance under various conditions, and 100% chlorophyll a removal rate could be achieved within 4 h of visible light irradiation under the optimal photocatalyst loading of 6 g/L. The effects of Ag2MoO4/TACN@LF floating catalyst on algal cell membrane permeability, phycobiliprotein, intracellular antioxidant enzyme activities and algal organic matter were further studied. Moreover, the scavenging experiments demonstrated that •OH was the predominant reactive oxygen species (ROSs). Ag0 and 3g-C3N4 * also made a non-negligible contribution to the inactivation of algal cells. What's more, the Ag2MoO4/TACN@LF still exhibited 92% inactivation efficiency for M. aeruginosa after 5 cycles reused experiments, indicating its promising potential for practical application of alleviating HABs.