Bisphosphonate nanocellulose in the removal of vanadium(V) from water

Due to environmental concerns and decreasing global resources, removing aqueous heavy metals from industrial wastewaters is important for ecological sustainability. In this work, the removal of vanadium from a synthetic aqueous solution using bisphosphonate nanocelluloses was studied. Bisphoshonate nanocellulose was obtained from periodate oxidized and sodium alendronate aminated wood cellulose fibers using a mechanical disintegration method. Depending on the reaction condition, long flexible nanofibrillated celluloses or shorter rigid cellulose nanocrystals (CNCs) were obtained. The most efficient removal of vanadium was obtained at low solution pH (2 and 3), which is most likely due to the complexation of vanadium with bisphosphonate groups and the electrostatic interaction between cationic vanadium species and anionic acid groups. Based on the Langmuir isotherm, a maximum adsorption capacity of 1.98 mmol/g was attained with the CNCs that had 0.32 mmol/g of bisphosphonate content. The adsorption kinetic of vanadium was modeled and found to follow a pseudo-second-order model.