Modification and derivatization of cellulose-based nanobiosorbents and their utilization in environmental remediation

Abstract

The ever increasing problem of water pollution demands for the development of sustainable solutions employing low-cost and environmentally safe materials. Nanocellulose is one of the most promising biopolymers that can be used as a low-cost and sustainable adsorbent to remove both organic and inorganic pollutants from aqueous media. Its widespread use and promising potential as absorbent material stem from its unique properties such as high specific surface area and good mechanical strength, easy surface modification with a broad range of functional groups and the possibility of blending it with other materials to make efficient composite adsorbents for enhanced removal of pollutants. This chapter first provides a brief introduction of the cellulose-based biosorbents with reference to their advantage and limitations and then provides an overview of the possible chemical modifications of cellulose including chemical grafting of chelating or metal-binding functionalities and/or charge-bearing functional groups on the cellulose backbone that have been studied to further enhance and tailor the adsorptive properties of cellulose for effective environmental remediation. Particular emphasis is placed on the hydrophobic modifications of cellulose for organics capture and removal of oil and other organic solvents from aqueous media. Finally, recent updates on cellulose/inorganic nanostructures organic-inorganic hybrid materials, especially the formation of cellulose/inorganic semiconductor photocatalysts and their adsorptive-cum-photocatalytic properties have been outlined. Such composites are particularly relevant as they not only remove the pollutants from aqueous media through adsorption but also have the potential to photocatalytically degrade the adsorbed pollutants and/or transform them into less toxic products.