Non-equilibrium zinc uptake onto compost particles from synthetic stormwater

► Zinc uptake from synthetic stormwater on various compost particle sizes was studied. ► Uptake on smaller particles conformed to equilibrium assumptions. ► Intra-particle diffusion caused rate limited metal uptake on larger particles. ► Non-equilibrium modelling adequately modelled larger particles. ► Design of bioretention systems should consider filtration media particle size.