A theoretical and experimental study on the P-adsorption capacity of Phoslock™

The main objective of this study is to investigate the adsorption process from both experimental and modeling point of view of phosphate onto Phoslock (TM), 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 agreement is perfect for T = 25 degrees C, it becomes more and more poor as temperature decreases, approaching approx. 10% difference for the low temperature of 10 degrees C. This inconsistency between experiments and model can be attributed to the internal inefficiencies of unit cell approach, which in particular over estimates the adsorption efficiency. (C) 2015 Elsevier B.V. All rights reserved.