[A-HW18] Hydrology & Water Environment

[AHW18-P06] Development of Granular Polysulfone Composites with Bentonite and Kaolinite for Efficient Uranium Adsorption in Aqueous Environments

*Subeen Kim¹, Hyerim Lee¹, Minjune Yang^2,3 (1.Division of Earth Environmental System Sciences-Major of Earth & Environmental Sciences, Pukyong National University, 2.Division of Earth and Environmental System Sciences-Major of Environmental Geosciences, Pukyong National University, 3.Wible Co., Ltd.)

Keywords:Adsorption, Polysulfone, Bentonite, Kaolinite, Uranium, Granular Adsorbent

Adsorption is widely recognized as a cost-effective method for removing contaminants from aqueous solutions. However, the prevalent development of adsorbents in powder form presents challenges for their recovery post-use. Polysulfone (PSF) is a polymer known for its remarkable chemical stability, mechanical resistance, and formability. Bentonite and kaolinite, non-toxic clay minerals with 2:1 and 1:1 crystal structure layers, respectively, were combined with PSF to develop granular composites named BPSF and KPSF. The uranium adsorption characteristics of BPSF and KPSF were investigated under various experimental conditions, including pHs (4, 7, and 9), contact times (1, 10, 30, 60, 360, 720, and 1440 min) and initial uranium concentrations (0.05 – 5 mg/L). The results of the BPSF adsorption experiment showed high adsorption efficiencies at pH 4 (99.3%) and pH 7 (98.1%), but its efficiency decreased to 55.2% at pH 9. The results of the KPSF adsorption experiment showed a slightly higher uranium adsorption efficiency only at pH 7 (84.9%), with less than 60% efficiency at other pHs. The adsorption behavior of BPSF was well described by the Langmuir model (R²= 0.999), while that of KPSF fit the Sips model (R²= 0.999). Kinetic studies indicated that both BPSF and KPSF followed the pseudo-second-order model (BPSF; R²= 0.951 and KPSF; R²=0.856) rather than the pseudo-first-order model (BPSF; R²= 0.937 and KPSF; R²= 0.833). The results suggest that the adsorption process is predominantly controlled by chemical interactions, supporting the formation of strong bonds between the adsorbent and uranium ions. In summary, BPSF demonstrates significant uranium adsorption capacity, particularly at pH 4 and pH 7, while KPSF presents enhanced efficiency, especially at pH 7. These encouraging results suggest potential application of these composites in remediating uranium-contaminated aqueous systems. Future studies will focus on verifying the reusability of adsorbents and exploring practical applications further.

Acknowledgements: This research was supported by the Learning & Academic Research Institution for Master's·PhD students, and Postdocs (LAMP) Program of the National Research Foundation of Korea (NRF), grant funded by the Ministry of Education (Grant No. RS-2023-00301702).