Different types of bubbly flows in a confined channel with the aim of limiting microalgae biofilm development – Part II: Study of the development and removal of microalgae biofilm

•The role of bubble passage in biofouling prevention or biofilm removal in thin gap photobioreactors is investigated.•The case of Taylor bubbles, bubbles slightly smaller than the gap and small bubbles is investigated.•It is shown that it is very difficult to detach the biofilm once it has adhered to the wall.•Biofilm can be compacted by confined bubbles.•Small millimetric bubbles create the most important shear rate fluctuations and can limit biofouling.