Amine-functionalized cellulose-silica composites for the remediation of hexavalent chromium (Cr IV) in contaminated water

Mayenzeke Trueman Mazibuko; Stanley Chibuzor Onwubu; Phumlane Selby Mdluli; Vimla Paul; Mokhena Clement Teboho; Mokhothu Thabang

Results in Chemistry (Oct 2024)

Amine-functionalized cellulose-silica composites for the remediation of hexavalent chromium (Cr IV) in contaminated water

Mayenzeke Trueman Mazibuko,
Stanley Chibuzor Onwubu,
Phumlane Selby Mdluli,
Vimla Paul,
Mokhena Clement Teboho,
Mokhothu Thabang

Affiliations

Mayenzeke Trueman Mazibuko: Chemistry Department, Durban University of Technology, Durban, South Africa
Stanley Chibuzor Onwubu: Chemistry Department, Durban University of Technology, Durban, South Africa; Corresponding author.
Phumlane Selby Mdluli: Chemistry Department, Durban University of Technology, Durban, South Africa; Health Platform, Advanced Materials Division, Mintek, Randburg, South Africa
Vimla Paul: Chemistry Department, Durban University of Technology, Durban, South Africa
Mokhena Clement Teboho: Health Platform, Advanced Materials Division, Mintek, Randburg, South Africa
Mokhothu Thabang: Chemistry Department, Durban University of Technology, Durban, South Africa

Journal volume & issue: Vol. 11
p. 101796

Abstract

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Adsorption method for Hexavalent chromium (Cr(VI) removal from domestic and industrial wastewater is widely desirable due to public health concern of the heavy metal. The purpose of this study was to investigate the evaluation of Cr(VI) adsorption using a novel adsorbent: amine-functionalized cellulose-silica composite derived from banana fibers. We employed the in-situ sol–gel method to create cellulose-silica silane functionalized composites, analyzing them through different characterization techniques such as Attenuated total reflectance- Fourier transform infrared spectroscopy (ATR-FTIR), X-ray Diffraction Analysis (XRD), Thermo gravimetric analysis (TGA)/differential thermogravimetric (DTG), Brunauer–Emmett–Teller (BET), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM) techniques. ATR-FTIR depicted key organic constituents in raw banana pseudo stem fibers (BF) and the formation of SiO bonds in BCSiO2 composite, and further enhanced by the grafting of N-[3-(trimethoxysilyl)propyl ethylenediamine (DAPTMS) onto the BC-SiO2 surface in BC-SiO2-DAPTMS. XRD and TGA/DTG analyses revealed changes in crystallinity and thermal stability, while BET analysis showcased altered surface area and pore characteristics in BC-SiO2-DAPTMS (2 %). SEM and TEM imaging provided visual evidence of structural modifications and improved dispersion in BC-SiO2-DAPTMS composites. The impact of composite weight, contact time, and pH on Cr(VI) removal rates was examined, revealing optimal performance at slightly acidic pH 4 value (80.7 %) and enhanced efficiency with increased contact time of 65 min (86.66 %), composite weight of 1 g (82.62 %), and initial concentration was for 0.8 mg/l (80 %). The kinetics and isotherms analyzed using pseudo second order (PSO) and pseudo first order (PFO) models, highlight the composite’s efficiency. The Freundlich model was found to better fit the adsorption isotherm data, while the PSO model described the kinetics more accurately. These insights contribute to optimizing the BC-SiO2-DAPTMS (2 %) composite for efficient Cr(VI) ion removal in water treatment applications.

Published in Results in Chemistry

ISSN: 2211-7156 (Online)
Publisher: Elsevier
Country of publisher: Netherlands
LCC subjects: Science: Chemistry
Website: https://www.journals.elsevier.com/results-in-chemistry/

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