Mass Transfer Limitations: An Overlooked Factor in the Decline of Anammox Granular Activity for Treating Sulfate-Rich High-Salinity Wastewater

enrichment on EPS-polysaccharides and the microporous architecture of granules, preferentially occurred in narrow pores and high-curvature regions. The resulting pore blockage accounted for ∼40% of the observed decline in anammox activity, primarily through restricted substrate diffusion. By highlighting the roles of sulfate and calcium in restricting mass transfer in anammox granules, this work provides a mechanistic basis for optimizing the performance of anammox systems.