Preparation and modification of nanocellulose and its application to heavy metal adsorption: A review

Heavy metals are a notable pollutant in aquatic ecosystems that results in many deadly diseases of the human body after enrichment through the food chain. As an environmentally friendly renewable resource, nanocellulose can be competitive with other materials at removing heavy metal ions due to its large specific surface area, high mechanical strength, biocompatibility and low cost. In this review, the research status of modified nanocellulose for heavy metal adsorbents is primarily reviewed. Two primary forms of nanocellulose are cellulose nanocrystals (CNCs) and cellulose nanofibers (CNFs). The preparation process of nanocellulose was derived from natural plants, and the preparation process included noncellulosic constituent removal and extraction of nanocellulose. Focusing on heavy metal adsorption, the modification of nanocellulose was explored in depth, including direct modification methods, surface grafting modification methods based on free radical polymerization and physical activation. The adsorption principles of nanocellulose-based adsorbents when removing heavy metals are analyzed in detail. This review may further facilitate the application of the modified nanocellulose in the field of heavy metal removal.

Automated summary

Heavy metals are a significant pollutant in aquatic ecosystems, causing deadly diseases in humans after being enriched through the food chain. Nanocellulose, as an environmentally friendly renewable resource, has the potential to compete with other materials in removing heavy metal ions due to its large specific surface area, high mechanical strength, biocompatibility, and low cost. This review primarily discusses the research status of modified nanocellulose for heavy metal adsorbents, focusing on the preparation process, modification methods, and adsorption principles. The findings may promote the application of modified nanocellulose in the field of heavy metal removal.