Synthesis and Performance Evaluation of Hexadecyltrimethylammonium Bromide-Functionalized Cellulose Nanocrystal (HDTMA-Br/CNCs) for Adsorptive Removal of Phenol in Synthetic Phenol-Containing Wastewater

Phenol is classified as a priority contaminant regardless of its useful applications, due to its potential harm to humans and other organisms at low concentrations. Therefore, to protect the environment, humans, and organisms from the harmful effects of phenol, phenol-containing wastewater should be treated to remove the phenol. This study, for the first time, investigates the synthesis and performance evaluation of hexadecyltrimethylammonium bromide-functionalized cellulose nanocrystals (HDTMA-Br/CNCs) adsorbent for the removal of phenol from synthetic phenol-containing wastewater. The CNCs were prepared from as-received cellulose, by mixed acid hydrolysis consisting of sulfuric acid, glacial acetic acid, and deionized water in a mass ratio of 1:7:2. About 20 g of the prepared CNCs were functionalized in, and stirred for 120 minutes. The synthesized and HDTMA-Br-functionalized CNCs were characterized using different characterization techniques, such as scanning electron microscopy (SEM) to examine the surface morphology of the modified and unmodified adsorbents. Fourier transform infrared (FTIR) was used to examine the attachment of the functional group. To evaluate the performance of the synthesized adsorbent in batch mode, 1 g/L of phenol was used to prepare the synthetic phenol-containing wastewater. The analysis of the feed and permeate was done using pre-calibrated High-Performance Liquid Chromatography (HPLC). About 75% phenol removal was obtained for the functionalized CNCs compared to the non-functionalized CNCs adsorbent having 43% phenol removal at 35 °C reaction temperature. The Langmuir and Freundlich isotherms provided the best match to the experimental data, while the pseudo-first-order kinetic model provided the greatest fit to the kinetic data. Thus far, the results suggest that modified CNCs may be an alternative adsorption material for phenol removal in wastewater.