The main objective of this study is to investigate the adsorption process from both experimental and modeling point of view of phosphate onto PhoslockTM, an increasingly used worldwide restoration tool to control phosphorus from natural water ecosystems. Bench-scale batch experiments were performed to examine its efficiency as a phosphate adsorbent and detailed simulations were carried out, allowing for a deep insight of the removal process. The adsorption efficiency calculated by the simulations is 87.41%, being in excellent agreement with that experimentally measured (approx. 87%). However, it is important to notice the discrepancy between experimental measures and simulation estimates. Although the agreementis perfectfor T = 25 ◦C, it becomes more and more poor as temperature decreases, approaching approx. 10% difference for the low temperature of 10 ◦C. This inconsistency between experiments and model can be attributed to the internal inefficiencies of unit cell approach, which in particular overestimates the adsorption efficiency.