Nanocellulose-based Composite Hydrogels for Water Remediation

Abstract

Water quality issues caused by chemical contaminants are a major challenge that humanity is facing in the twenty-first century. Designing an environmentally benign bio-adsorbent material for the removal of pollutants from water resources was a sustainable strategy to ensure water safety. Nanocellulose is an attractive candidate for water remediation owing to abundant renewable resources and tunable physicochemical characteristics. However, most of them are synthesized by chemical cross-linkers, which usually cause a second pollution and extra cost. Moreover, most nanocellulose composites adsorbents are available in powder form, which present poor separability and recyclability. In order to address these issues, the main objective of this dissertation is to design and synthesize stable nanocellulose-based 3-D composite hydrogels by self-assembly mechanisms for water remediation. Their chemical, morphology, and surface properties were characterized, and their adsorption behavior for toxic dyes, heavy metal ions, oil spills was investigated in terms of the optimal functionalized polymer content, pH effect, kinetics, and isotherm models. The results show that after functionalization, their adsorption capability for toxic dyes, metals ions and oils are all significantly increase, especially for toxic dyes due to the electrostatic attraction mechanism. This work not only provides a simple and cost-effective synthetic route to nanocellulose-based 3-D composite adsorbents, but also offers valuable clues for the removal of multiple water pollutants.