Explaining non-monotonic retention profiles during flow of size-distributed colloids

•Non-monotonic retention profiles during colloidal flows are due to colloid heterogeneity.•Exact upscaling of colloidal flow with fines adsorption, flux accessibility and reduction.•Analytical model for 1D flow with colloid sorption, accessibility, and flux reduction.•The analytical model exhibits non-monotonic retention profiles.•Five-parametric model closely marches 7-dimensional lab-data array, validating the model.