Per- and polyfluoroalkyl substances (PFAS) are widely detected contaminants in water due to their exceptional chemical stability. Conventional treatments for short-chain PFAS often perform poorly and require energy-intensive separation. This study aims to (i) evaluate the optimal activation method to convert soybean hull biomass into activated carbon for PFAS removal by synthesizing soybean hull–derived activated carbon (SHAC) and its magnetically enabled counterpart (M-SHAC), (ii) investigate the optimal sorbent doses, adsorption kinetics, and removal efficiency of PFAS using both materials, and (iii) identify the impact of background on PFAS removal from wastewater effluents. SHAC was activated using KOH and ZnCl₂, and M-SHAC was prepared through Fe₃O₄ nanoparticle deposition. KOH activation produced the best-performing SHAC, with the highest surface area and microporous structure. Adsorption experiments were conducted using short- and long-chain PFAS compounds. SHAC demonstrated superior adsorption performance compared to MSHAC and commercial activated carbon (F400), achieving near-complete removal of long-chain PFAS even at low sorbent doses. Short-chain PFAS removal improved with increasing sorbent dosage but remained lower due to their higher solubility and weaker hydrophobic interactions. SHAC exhibited substantially higher removal efficiencies for short-chain PFAS compared to F400 across all tested doses. Kinetic modeling indicated that the pseudo-second order model provided the best fit to the data, suggesting that adsorption is primarily governed by surface interactions and pore-filling mechanisms. Competition from effluent organic matter in wastewater effluent background had little impact on PFAS adsorption. Overall, SHAC represents a sustainable adsorbent for PFAS removal from water systems, offering a value-added pathway for agricultural waste in drinking water and wastewater treatment.