Impact of microplastics on organic fouling of hollow fiber membranes

•MRI used to non-invasively resolve the flow field in a microcapillary membrane module.•Fouling predominately resulted in the elimination of flow from specific fibers.•Fouling detection was clear via MRI but not by pressure drop measurements.•Microplastics resulted in less fouling when combined with alginate than for alginate fouling alone.•Fouling involving microplastics was significantly easier to remediate.