Adsorption of Chromium (VI) from Aqueous Solution Using Zeolit/Chitosan Hybrid Composite

Abstract

This study investigated the adsorption ability of ZCHC (zeolite/chitosan hybrid composite) as adsorbent for chromium (Cr(VI)), ZCHC was prepared with sol-gel method by mixing zeolite and chitosan. Adsorption experiment from aqueous solutions containing known amount of Cr(VI) using zeolite, chitosan and ZCHC was explored to evaluate the efficiency of ZCHC as adsorbent for Cr in a batch system. The amount of Cr(VI) adsorbed at different pH values, initial concentrations, adsorbent dosages, and contact times were determined by ICP-AES (inductively coupled plasma-atomic emission spectrometry) in order to determine the optimum conditions for Cr(VI) adsorption. Furthermore, the adsorption mechanism of Cr(VI) by zeolite, chitosan and ZCHC was investigated by applying Langmuir and Freundlich isotherm equations to the data obtained. In addition, the rates of adsorption were found to conform to pseudo-second order kinetics.

Investigation of Calcination Duration on the Surface Morphology and Specific Surface Area of Zeolite-Chitosan Composite with Oil Palm Ash for Potential Water Contaminant Remediation

“…When zooming in at 3000x magnification (Fig. 3b), a notably heightened surface roughness becomes apparent, indicating a substantial restructuring brought about by the 3-hour calcination process [18]. SEM images of Sample 3 reveal the profound impact of a 3-hour calcination on the composite's microstructure.…”

“…The prolonged calcination duration allows for extended thermal-induced reactions, leading to more extensive decomposition and vaporization of organic compounds [18]. This process results in the formation of larger and more interconnected pores, which enhances the accessibility of water contaminants to the adsorption sites within the composite [9].…”

“…Figure 3 displays SEM images of Sample 3, captured at 1500x and 3000x magnifications.The microstructure observed at 1500x magnification (Fig.3a) reveals a more advanced porous network, featuring intricate surface characteristics with numerous irregular pores and fissures. When zooming in at 3000x magnification (Fig.3b), a notably heightened surface roughness becomes apparent, indicating a substantial restructuring brought about by the 3-hour calcination process[18].…”

Preparation of magnetic zeolite/chitosan composite using silane as modifier for adsorption of Cr(VI) from aqueous solutions

“…[6] However, there are considerable drawbacks such as poor recovery, low mechanical strength, swelling, and chemical resistance, limiting its application, [7] and the application of chitosan-based adsorbents are also limited in part due to the high cost, [4,8,9] slow adsorption rate, [10,11] low adsorption capacity, [12] and difficult retrievability after adsorption. [13,14] Zeolite can accommodate different positively charged ions, molecules, and cations because its three-dimensional microcrystalline pore spaces (3-4 Å) create a natural molecular sieve. [7] Besides, it can improve the reusability of chitosan-based adsorbents.…”

“…[23] On the basis of retaining their original excellent properties, it cannot only improve the adsorption performance but also facilitate solid-liquid separation. [24] Finally, in contrast to previous inorganic/chitosan studies, such as ZFA/CS, [13,14] Fe 3 O 4 /CS/Al(OH) 3 , [25] CS/ MWCNT/Fe 3 O 4 , [4] the dispersion and compatibility of inorganic particles in the chitosan matrix is considered in this work. GPTMS was selected as a modifier and crosslinker.…”