<p>The transport and retention behaviors of graphene oxide (GO) in saturated porous media were examined in systems containing heavy metals (Cd²⁺, Zn²⁺, Cr³⁺), with a focus on the effects of ionic strength (IS) and cation type. Both IS and cation type were found to be key factors governing GO retention. Notably, Cr³⁺ most effectively inhibited GO transport, a result attributed to its strong charge shielding and promotion of straining. At a low IS of 0.3 mM, the inhibitory effects of Cr³⁺, Cd²⁺, and Zn²⁺ on GO transport followed the Hofmeister series. Higher IS (3 mM) led to greater GO deposition. In the presence of 3 mM Cd²⁺ and Zn²⁺, the remobilization of retained GO was evidenced by double peaks in breakthrough curves, attributed to cation exchange and reduced IS, indicating reversible retention. In contrast, significant retention with no release (irreversible retention) occurred under Cr³⁺ even at a low IS (&lt; 0.6 mM). Combined analysis of GO aggregation, interaction energy, and CFT confirmed that double-layer compression, cation bridging, and straining collectively governed GO retention, leading to retention profiles (uniform, exponential, or hyper-exponential) that depended on IS and cation type. These results are valuable for understanding the coupled environmental fate of GO and heavy metals in subsurface systems and are critical for assessing groundwater contamination risks under transient solution chemistry.</p>