Cellulose Nanocrystal-Zero Valent Iron Nanocomposites For groundwater remediation
Zero-valent iron nanoparticles (nano-ZVI) have been widely studied for in-situ remediation of groundwater and other environmental matrices. Nano-ZVI particle mobility and reactivity are still the main impediments in achieving an efficient in-situ groundwater remediation. Compared to nano-ZVI “coating” strategy, the nano-ZVI stabilization on supporting material allows a direct contact with the contaminant, reduces the electron path from nano-ZVI to the target contaminant and increases nano-ZVI reactivity. Herein, we report the synthesis of nano-ZVI stabilize by cellulose nanocrystals (CNC) rigid nanomaterials (CNC-nano-ZVI; Fe/CNC=1 w/w) with two different CNC functional surfaces (-OH and –COOH) using a classic sodium borohydride synthesis pathway. The final nanocomposites were thoroughly characterized and the reactivity of CNC-nano-ZVI was assessed by their methyl orange (MO) dye degradation potential. Mobility of nanocomposites was detrmined in (sand/glassbead) porous media by utilizing a series of flowthrough transport column experiments. The synthesized CNC-nano-ZVI provided a stable colloidal suspension and demonstated high mobility in porous media with an attachment efficiency (α) value of less than 0.23. In addition, reactivity toward MO increased up to 25 % compared to bare ZVI. The use of CNC as a delivery vehicle show promising potential to further improve the capabilities and applicabilities of nano-ZVI for in-situ groundwater remediation and can spur advancements in CNC-based nanocomposites for their application in environmental remediation.