A novel and efficient method on the recovery of nanosized CeO₂ in Ce³⁺ wastewater remediation using modified sawdust...

In this study, by using heterogeneous esterification reaction and UV photo-induced technology, dendritic polyacrylic acid (PAA) was successfully grafted on to the surface of pinewood sawdust (PSD) particles to be used as an adsorbent and recovery medium for Ce³⁺ from wastewater. 18 alkyl acid (stearic acid, SA), as a pre-modifier, was grafted onto the PSD surface. The outcome was the replacement of hydroxyl groups by hydrocarbon chains. Therefore, rich hydrogen atoms of the hydrocarbon chains on the PSD particles became sites whom can be taken away by photosensitizer molecules to form surface radicals. Acrylic molecules can be initiated polymerization by these radicals, PAA chains were grafted on to PSD surface via "grafting from" method, forming dendritic functional polymer layers around the PSD particles. The end product (PSD-g-PAA) have a good adsorption performance for Ce³⁺ (adsorption capacity reached 153.90mg/g), can be used as a carrier to recycle the Cerium oxide. And desorption and reusability experiment suggested that the adsorption capacity was virtually unchanged after five cycles and the desorption rate is almost 100% in every cycle. The adsorption achieves equilibrium after about 120min. The kinetic and thermodynamic investigations as well as isotherm analysis were also undertaken.