To gain a detailed insight in the PFOA adsorption kinetics for MIL-96-RHPAM2, vapor phase adsorption experiments were conducted with a hydrocarbon analogue to PFOA; n-octane (C8H18) (Figure ). The fundamental differences in liquid-phase adsorption and vapor adsorption are acknowledged but, in both cases, the kinetic rate is nonetheless similar (denoted by the proximity of k2 = 2 × 10 -4 g/mg.min). Vapor phase adsorption time of 1000 minutes is still insufficient to realize an equilibrium adsorption state. The BET result shows that although increasing the HPAM content increases the particle size (Figure and Table ), it has compromised the material's porosity. In turn, there is an increase in the diffusion path length inside the adsorbent that hindered effective diffusion and prolonging the time required to reach equilibrium. It may appear that the approach outlined here has created another problem but, there is a future opportunity to retain the beneficial effect provided by HPAM by tuning MIL-96 adsorption capacity with temperature, taking into account the high thermal stability of HPAM and the flexibility of changing, increasing, its pore size. 70 In comparison to the reported kinetic data for PFOA removal by several other adsorbents, MIL-96-RHPAM2 can adsorb PFOA at loading levels on a par with other adsorbents, but the extremely slow uptake would be a significant drawback for its practical use. Relative to other adsorption studies displayed in Table , the PFOA concentration used in this work is the highest. PFOA Adsorption and Desorption. Knowing that PFCs are hazardous chemicals, safe regeneration and economical reuse of the spent adsorbents is critically important. Although thermal regeneration is preferably used by carbon manufacturers, adsorbed PFCs are not easily removed from the carbon surfaces by decomposition as C-F is the strongest single bond in organic chemistry after B-F, Si-F and H-F. While the next best alternative is to use higher regeneration temperatures to break the C-F bond, this often results in high carbon losses. To develop an efficient PFOA regeneration method from spent MOF, the nature of adsorption processes must first be understood. An earlier report on PFOA adsorption by MOF had confirmed the electrostatic interaction between the cationic MOF species (Al 3+ ) with the anionic carboxylate groups (COO -) of PFOA as the main binding mechanism, supplemented by H-bonding and hydrophobic interaction to a lesser extent. So, with electrostatic interaction being the most prevalent, it was decided to trial saline eluents to evaluate their destabilization effect on the electrostatic PFOA adsorption complex.