Enhanced Removal of Ammonium Ions and Organic Dyes from Wastewater Using Functionalized Nanocellulose: Investigating Adsorption Kinetics and Isotherm Models

Date of Award

12-2024

Degree Name

Master of Science in Engineering

Department

Chemistry

First Advisor

Priyanka Sharma, Ph.D.

Second Advisor

James Springstead, Ph.D.

Third Advisor

Mert Atilhan, Ph.D.

Access Setting

Masters Thesis-Abstract Only

Restricted to Campus until

12-1-2034

Abstract

Nanocellulose has been gaining popularity as green nanomaterials from plants with extensive raw material capacity for utilization in the removal of wastewater pollutants. Renewability, abundance, improved mechanical characteristics, high surface-to-volume ratio, biocompatibility, tunable functionality, and sustainability characterize these plant-derived raw materials. Consequently, nanocellulose emerges as a promising technology for the bioremediation of cationic and anionic dyes from wastewater. This is particularly significant, owing to the need and demand for a cost-effective adsorbent, sustainable raw materials, and a technology with a high dye removal success rate.

This study aimed to explore the performance of Cellulose Nanofibers (CNF) for the removal of ammonium ions (NH₄⁺) and Crystal Violet dye (CV). Essentially, the study examined the effectiveness and overall performance of CNF under operational conditions such as varying contact times, concentrations, and pH levels. The aim was to determine the best approach for cleaning wastewater from these eco-friendly materials. The study utilized ion-selective electrodes (ISE) to track the removal of ammonium ions NH₄⁺, while UV-spectroscopy was used to measure the removal efficiency of crystal violate. The CNF suspension method was particularly effective, showing significant changes in concentration following filtration using a syringe filter with a pore size of 0.22 μm, demonstrating effective separation.

For instance, the NH₄⁺ adsorption capacity of CNF reached a maximum (Qmax) of 303.03 mg/g, following the Langmuir isotherm model, indicating a monolayer adsorption mechanism. The Freundlich isotherm further highlighted heterogeneous surface interactions at lower NH₄⁺ concentrations. Kinetic studies revealed pseudo-second-order behavior, confirming chemisorption

as the dominant mechanism. The removal efficiency for NH₄⁺ peaked at 98% under optimal conditions of pH 7, with adsorption capacity decreasing beyond this due to the formation of ammonia (NH₃). CNF demonstrated effective adsorption for CV dye with a maximum capacity (Qmax) of 500 mg/g, adhering to both Langmuir and Freundlich isotherms. Electrostatic interactions drove the adsorption and π-π stacking between the dye molecules and CNF. At a pH of 7, CNF achieved the highest removal efficiency of 91%, indicating the importance of pH optimization in CV remediation. SEM and FTIR analyses confirmed significant morphological changes and functional group interactions on the CNF surface post-adsorption for both pollutants.

This research highlights the potential of CNF as a versatile, sustainable solution for the simultaneous removal of ammonium and dye pollutants, benefiting aquaculture systems and addressing broader environmental sustainability challenges.

This document is currently not available here.

Share

COinS