Remediation of heavy metals and dyes from wastewater using cellulose-based adsorbents

Heavy metals and dyes are major pollutants that pose potential threat to the health of humans and ecosystems. Various technologies are available to remediate such pollution, but these processes are costly, have high energy requirements and generate toxic sludges and wastes that need to be carefully disposed. There is therefore a need for methods that are more efficient, cost effective and environment friendly for water purification. Adsorption is regarded as a green, clean and versatile method for wastewater treatment. In particular, biodegradable and non-toxic materials such as cellulose-based materials are of interest for water purification. Moreover, the surface of cellulose contains many hydroxyl groups that facilitate the incorporation of chemical moieties, thereby improving pollutant adsorption. Here, we review the most relevant applications of cellulose-based materials for wastewater treatment. A major point is that reducing cellulosic dimension to nanometric levels highly improves adsorption of heavy metals and dyes from wastewaters. Nanocellulose and functionalized nanocellulose are thus promising for wastewater treatment.