Adsorption of Anionic Surfactants onto Alumina: Characteristics, Mechanisms, and Application for Heavy Metal Removal. (13th December 2018)

• Record Type: Journal Article
• Authors: Nguyen, Thi Minh Thu; Do, Thi Phuong Thao; Hoang, Thi Sim; Nguyen, Ngoc Viet; Pham, Huy Dong; Nguyen, Trung Dung; Pham, Thi Ngoc Mai; Le, Thanh Son; Pham, Tien Duc
• Other Names: Wang De-Yi Academic Editor.
• Is Part Of: International journal of polymer science. Volume 2018(2018)
• Publication Date: 2018-12-13
• Subjects: Polymers -- Periodicals; Polymers; Periodicals; 547.7
• DOI: 10.1155/2018/2830286
• Languages: English
• ISSNs: 1687-9422

Abstract

Abstract : We investigated adsorption of anionic surfactants, sodium dodecyl sulfate (SDS) and sodium tetradecyl sulfate (STS), onto alumina (Al2 O3 ) with large size in the present study. The effective conditions for SDS and STS adsorption onto Al2 O3 were systematically studied. The conditions for SDS and STS adsorption onto γ -Al2 O3 were optimized and found to be contact time 180 min, pH 4, and 1 mM NaCl. Adsorption of both SDS and STS onto large Al2 O3 beads increased with an increase of ionic strength, demonstrating that the adsorption is controlled by electrostatic attraction between anionic sulfate groups and positively charged Al2 O3 surface, as well as hydrophobic interactions between long alkyl chains of surfactant molecules. Nevertheless, the hydrophobic interaction in terms of STS adsorption is much higher than that of SDS adsorption. The obtained SDS and STS adsorption isotherms in different NaCl concentrations onto Al2 O3 beads were fitted well by two-step adsorption. Adsorption mechanisms were disused in detail on the basis of adsorption isotherm, the change in surface charge, and the change in functional surface groups by Fourier-transform infrared spectroscopy (FTIR). The application of surfactant adsorption onto Al2 O3 to remove cadmium ion (Cd 2+ ) was also studied. The optimum conditions for Cd 2+ removal using surfactant-modified alumina (SMA) are pH 6, contact time 120 min, and ionic strength 0.1 mM NaCl. Under optimum conditions, the removal efficiency of Cd 2+ using SMA increased significantly. We demonstrate that SMA is a novel adsorbent for removal of Cd 2+ from aqueous solution.