## 4 Conclusions  
In this study, a commercially available functionalized resin was successfully applied for the efficient adsorption of high-concentration m-cresol (20 g L\({}^{-1}\)) from aqueous solution. Comprehensive characterization revealed that the XDA-1G resin possesses a high BET surface area (1439 m\({}^{2}\) g\({}^{-1}\)), a hierarchical micro-mesoporous structure, and abundant surface functional groups (e.g., hydroxyl, carbonyl), which synergistically contribute to its high adsorption performance. Batch adsorption experiments demonstrated that under optimized conditions (0.15 g resin, 60 \({}^{\circ}\)C), a maximum adsorption capacity of 556.3 mg g\({}^{-1}\) was achieved, with a removal efficiency exceeding 71%. Kinetic analysis showed that the adsorption process followed the pseudo-second-order model (R\({}^{2}\) > 0.99), indicative of chemisorption. Isotherm analysis confirmed that the Langmuir model best described the equilibrium behavior (R\({}^{2}\) = 0.9953), with a maximum monolayer capacity of 833.3 mg g\({}^{-1}\). Thermodynamic parameters (\(\Delta\)H\({}^{\circ}\) = 9.090 kJ mol\({}^{-1}\) and \(\Delta\)S\({}^{\circ}\) = 35.09 J K\({}^{-1}\) mol\({}^{-1}\)) revealed that the adsorption was spontaneous and endothermic. The novelty of this work lies in its demonstration of high-efficiency adsorption at industrially relevant m-cresol concentrations, which are often overlooked in conventional studies that focus on dilute solutions. The successful performance at 20 g L\({}^{-1}\) m-cresol positions this resin as a promising candidate for treating coal-based or phenol-rich industrial effluents, where both adsorption capacity and economic resin utilization are critical. Furthermore, the adsorption mechanism was clarified through integrated modeling of adsorption kinetics, isotherms, and thermodynamics, in conjunction with in-depthphysicochemical characterization of the resin before adsorption, thereby reinforcing the understanding of its structure-function relationship with m-cresol. Overall, the findings provide new insights into the structure-performance relationship of functionalized resins and highlight their potential in the scalable treatment of concentrated phenolic wastewater. The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/ma18153628/s1](https://www.mdpi.com/article/10.3390/ma18153628/s1)]([https://www.mdpi.com/article/10.3390/ma18153628/s1](https://www.mdpi.com/article/10.3390/ma18153628/s1)), Figure S1: Kinetic fitting of m-cresol adsorption onto XDA-1G resin using nonlinear models. (a) First-order model; (b) second-order model. Adsorption equilibrium was reached at approximately 480 minutes; Figure S2: Isotherm modeling of m-cresol adsorption onto the XDA-1G resin. (a) Langmuir, (b) Freundlich, and (c) Temkin isotherm fits, with non-linear fit showing the relationship between equilibrium concentration and adsorption capacity, demonstrating the applicability of different adsorption models to describe m-cresol's uptake behavior; Table S1: Effect of resin mass on the removal efficiency and adsorption capacity of m-cresol; Table S2: Effect of contact time and temperature on the removal efficiency and adsorption capacity of m-cresol on 0.15 g resin; Table S3: Effect of temperature on the removal efficiency and adsorption capacity of m-cresol on 0.15 g resin; Table S4: Adsorption isotherm parameters of m-cresol's adsorption on resin based on non-linear fit; Table S5: The non-linear fitted parameters of kinetic models for m-cresol adsorption on 0.15 g of resin. References [41; 42; 43; 44; 45; 46; 47; 48] have been cited in Supplementary Materials file. [PERSON] provided data processing and editing. [PERSON] helped with data collection. [PERSON] provided the data analysis. [PERSON] provided conceptualization, funding acquisition, investigation, project administration, validation, and writing and editing the manuscript. [PERSON] provided manuscript revision and the conceptualization.