Sono-assisted adsorption of nitrate by Fe-modified chitosan–zeolite composite material

Abstract

The negative consequences of nitrate pollution on the environment and human health, that gained substantial attention. The purpose of this work is to formulate and evaluate the potential of the Fe-modified chitosan–zeolite composite (CZFC) as an efficient adsorbent for the removal of nitrate. Physical and chemical characterization techniques such as SEM, XRD, and FTIR were used to analyze the surface and structural properties of the CZFC. The effects of several variables, including the pH, contact time, initial concentration, and adsorbent dosage, were investigated under ultrasonication treatment throughout experiments. When compared to the Freundlich and Temkin models, the Langmuir models had the highest R² value (0.99), indicating that they had the best fitting for all the experimental data. The maximum adsorption capacity was found to be 5.18 ± 0.30 mg g⁻¹ with 95.37 ± 2.11% of nitrate removal at pH 3 and 2 g L⁻¹ of adsorbent dose. The pseudo-second-order model exhibited the highest R² value (0.99) and proved the chemisorption mechanism for nitrate removal. The thermodynamic properties indicated that the adsorption was spontaneous and exothermic. The regeneration capacity of the CZFC was found to be 80.86 ± 4.17% at pH 10 due to the weakening of electrostatic attraction. According to experimental results, ultrasonication treatment was crucial for increasing nitrate absorption on synthesized CZFC.

Graphical Abstract

Keywords:

• Adsorption
• chitosan
• regeneration
• ultrasonication
• zeolite

Acknowledgment

We are appreciative to the Vellore Institute of Technology, Vellore for giving us a better chance to conduct our research work.

Disclosure statement

The authors report there are no competing interests to declare.

Data availability statement

The authors confirm that the data supporting the findings of this study are available within the article [and/or] its supplementary materials.