Fibrous polyester sponge modified with carboxymethyl cellulose and Zeolitic imidazolate frameworks for methylene blue dye removal in batch and continuous adsorption processes

Abstract

Zeolitic imidazolate framework materials belong to an important class of Metal-organic frameworks that show attractive applications in various fields including adsorption and chemical separation. In this study, nonwoven fibrous polyester sponge surface was modified by cross-linked carboxymethyl cellulose and synthesized ZIF-8 and used to remove methylene blue dye from aqueous solution. The prepared filter was characterized using Field Scanning Electron Microscopy, Fourier Transform Infrared Spectrometer, X-ray Diffraction, and nitrogen adsorption-desorption analyses, and effects of contact time and dye concentration were investigated in batch and continuous fixed bed dye adsorption processes. Batch kinetics experimental data were estimated with the models of pseudo-first-order, pseudo-second-order, Elovich, and intra-particle, and continuous kinetics experimental data were estimated with Thomas, Adams-Bohart, and Yoon-Nelson models. Batch and continuous adsorption kinetics were more consistent with the pseudo-second-order and the Yoon-Nelson models, respectively. The filter adsorption capacity were 0.824 and 0.829 mg/g in continuous and batch systems at initial concentration of 8 mg/L, respectively. With increasing initial dye concentration from 2 to 8 mg/L, the adsorption capacity was increased about 80 and 90% in batch and continuous systems, respectively. By regeneration experiments after 5 cycles, acceptable results were observed.