Influence of NaCl salinity on the aggregation performance of anammox granules

•Salinity was not conducive to the aggregation performance of anammox granules.•Salinity led to a lower zeta potential and hydrophobicity of anammox granules.•Salinity increased the repulsive barrier of anammox granules aggregation.•Salinity changed the EPS contents and functional groups of anammox granules.