Selective Adsorption and Removal of Congo Red Based on Ethylenediamine Functionalized Mesoporous Silica

Abstract

Five types of mesoporous silica-based adsorbents were prepared by rationally implementing five diverse aminecontaining functional units into the mesoporous SBA-15 structures. The prepared materials were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, N 2 adsorptionÀ desorption isotherms and thermogravimetric analysis. Among the five adsorbents, the ethylenediamine functionalized SBA-15, namely, AAPTMS-SBA-15, achieved the complete adsorption of Congo red (CR) at pH 6.0, with the maximum adsorption capacity of 4608 mg/g. The AAPTMS-SBA-15 materi-al was used effectively for CR adsorption from the individual and binary dye aqueous solutions, indicating that AAPTMS-SBA-15 can selectively remove and separate CR from wastewater. The hydrogen bonding interactions between AAPTMS-SBA-15 and CR were beneficial to the high selectivity and excellent adsorption capacity of AAPTMS-SBA-15 toward CR. Moreover, the selective adsorption and efficient separation of CR realized the recovery and reusability of AAPTMS-SBA-15 and CR, which can not only avoid secondary environmental pollution, but also save economic costs.

Removal of methyl red from wastewater using a NiO@Hyphaene thebaicaseed-derived porous carbon adsorbent: kinetics and isotherm studies

“…3,4 Removing or minimizing dyes from wastewater has attracted attention worldwide due to the emission hazards, which are harmful to humans and the aquatic environment. 2,5,6 Even if a small amount of coloured dye is discharged into the water, it is visually unappealing. 7 The dyes used in industries are generally classified as cationic, anionic, or natural dyes.…”