Nanocellulose-based materials for the removal of metal ions, pharmaceuticals, pesticides, dyes, and other pollutants from aqueous environments: A review

Water contamination from metal ions, drugs, pesticides, dyes, oils, surfactants, and other pollutants from household, industrial, municipal, and agricultural activities poses significant risks to ecosystems and human health. Nanocellulose-based (bacterial cellulose, cellulose nanocrystals, and cellulose nanofibres) materials offer a sustainable and effective approach to water treatment by removing these contaminants through adsorption and catalytic degradation. In this review, the unique characteristics of nanocellulose, including its eco-friendliness, cost-effectiveness (especially when sourced from agricultural byproducts like bamboo, sugarcane bagasse, and wheat straw), large surface area, tunable functional groups, and ease of chemical modification, are explored for their role in water remediation. These materials can be fabricated into various forms, such as aerogels, hydrogels, membranes, beads, and composites, expanding their application in pollutant removal. Material morphology and structural factors, such as porosity, surface roughness, and specific surface area, are also highlighted for their critical influence on adsorption capacity and pollutant interaction efficiency. Mechanisms like electrostatic attraction, hydrogen bonding, π-π interactions, and hydrophobic interactions enable effective pollutant removal. The review also highlights nanocellulose’s selective adsorption capabilities, dual functionality (e.g., as both adsorbents and sensors), and multifunctionality. Additionally, the stability, reusability, and potential for enhancing adsorption through chemical modifications and composite formulations are discussed.