Per- and polyfluoroalkyl substances (PFAS) are persistent and toxic contaminants that are difficult to remove from complex wastewater because dissolved organic matter, salts, co-pollutants, and membrane fouling reduce treatment efficiency. This study evaluated an integrated adsorption-membrane process for PFAS removal through combined Aspen Plus/MATLAB simulation and bench-scale validation using synthetic complex wastewater. Adsorbent dosage (0.10-1.00 g/L), transmembrane pressure (4-10 bar), and filtration time were investigated. Standalone adsorption was limited by its reduced affinity for short-chain PFAS and by competitive uptake of co-existing dissolved organic matter, whereas standalone nanofiltration was constrained by progressive membrane fouling and flux decline; the integrated configuration was therefore designed to combine the strengths of both unit operations, using adsorptive pre-loading to lower the PFAS and organic load reaching the membrane so as to improve overall removal while mitigating fouling. Adsorption and nanofiltration achieved maximum total PFAS removals of 89.1% and 91.2%, respectively, while the integrated system reached 98.6% at 0.75 g/L PAC and 8 bar, with lower membrane flux decline (reduced from 33.5% to 21.8%) than NF-only operation. Model predictions showed good agreement with the experimental data (R² = 0.975-0.992), indicating that the integrated adsorption-membrane approach is a viable and scalable option for PFAS removal from complex wastewater.