Separation of heavy metal pollutants by micellar-enhanced ultrafiltration membrane system and its surfactant recovery

Nita Aryanti (Department of Chemical Engineering, Diponegoro University, Semarang 50275, Indonesia)
Heru Susanto (Department of Chemical Engineering, Diponegoro University, Semarang 50275, Indonesia)
I Nyoman Widiasa (Department of Chemical Engineering, Diponegoro University, Semarang 50275, Indonesia)
Nur Rokhati (Department of Chemical Engineering, Diponegoro University, Semarang 50275, Indonesia)
Aininu Nafiunisa (Department of Chemical Engineering, Diponegoro University, Semarang 50275, Indonesia)
Alifia Rizki Adina (Department of Chemical Engineering, Diponegoro University, Semarang 50275, Indonesia)
Arnaldi Dwilaksita (Department of Chemical Engineering, Diponegoro University, Semarang 50275, Indonesia)

Communications in Science and Technology
Vol 11 No 1 (2026)

Micellar-enhanced ultrafiltration (MEUF) is an effective treatment for treating heavy metal effluents. However, excessive use of synthetic surfactants leads to more serious problems, thereby highlighting the significance of surfactant recovery. This present study focuses on the recovery of surfactants while preserving their capacity to entrap metal ions. In this study, the acidification method was utilized to dissociate metal ions (Cu2+ and Cd2+) from the surfactant micelles. The findings demonstrate that the lowest critical micelle concentration found at pH 1, with 91% and 87% of the surfactant recovered for Cu2+ and Cd2+ system, respectively. The spontaneous occurrence of acidic surfactant micellization was thermodynamically validated, as evidenced by negative ΔGm values. Furthermore, the recovered surfactant exhibits high level of rejection and indicates an intermediate-blocking mechanism (R2>0.99). The findings highlight acid-assisted MEUF as a scalable approach for efficient metal removal and surfactant recovery, in turn, reducing chemical consumption and environmental impact.