Removal of chromate anions and immobilization using surfactant-modified zeolites

• DOI: 10.1016/j.jwpe.2020.101717
• Publication Date: 2020-10-07T07:22:00Z
• Authors: Gloria Lourdes Di...; Annia Martínez He...; Anna Fernanda Pér...; Ericka Lilian Riv...; Adriana Liñán Montes; Gerardo Antonio F...; Ladislao Sandoval...; Santiago Ivan Sua...; David Alejandro D...
• Keywords: 0211 other engineering and technologies; 02 engineering and technology

Abstract In this research surface modified zeolites, Linde Type A and clinoptilolite, were used for the chromate ions uptake from aqueous solutions as well as its encapsulation through a vitrification process. The surface chemistry of zeolites was modified using a cationic surfactant hexadecyltrimethylammonium (HDTMA) to promote the capability of anions uptake. The results of characterization by X-ray diffraction showed unique crystalline phases for each zeolite which remain unchanged after the incorporation of the surfactant. Evidence from Fourier-transform infrared spectroscopy studies revealed the effective bond of the HDTMA on the clinoptilolite surface. Results suggested that the presence of CH2− groups after the modification play a key role for the anion attraction. Kinetic studies revealed that surfactant-modified clinoptilolite was able to adsorb 9.83 mg/g of chromate and better fitted pseudo-second order model (R2 = 0.957). The equilibrium was better represented by Freundlich model (R2 = 0.993). Finally, the proposed vitrification process the spent zeolitic adsorbent was successful, avoiding leaching of chromate ions after two months at different pH values.