Novel green micelles Pluronic F-127 coating performance on nano zero-valent iron: Enhanced reactivity and innovative kinetics

Abstract

Abstract The reactivity of nano zero-valent iron (NZVI) tends to be significantly reduced due to its aggregation in liquid phase. To address this problem, for the first time, NZVI was successfully modified by green micelles Pluronic F-127 for reduction of Cr(VI) from wastewater. Pluronic F-127, a nontoxic and biodegradable copolymer, exhibits enhanced reactivity for removal of Cr(VI) by being coated on NZVI. The systematic observation and characterizations of (including SEM, TEM, and XRD) illustrate that, compared with bare nano zero-valent iron particles (BNZVI), the particle size of Pluronic F-127 modified NZVI (FNZVI) was decreased, while the dispersity and antioxidizability of FNZVI were increased. Furthermore, C O band appeared in XPS and FT-IR pattern of FNZVI indicated successful coating of Pluronic F-127 micelles on NZVI. This study also demonstrated that FNZVI dosage, initial pH value, and reaction temperature played an important role in the removal efficiency of Cr(VI). The removal efficiency of Cr(VI) could be increased by 37.56% by using FNZVI under optimal condition. Studies on the kinetics of Cr(VI) reacted with NZVI implied that their behaviors didn’t match the first- or pseudo-first-order kinetics due to dispersants on FNZVI or the presence of oxidation phases on the surface of BNZVI that could influence the whole reduction process by affecting the diffusion of Cr(VI) onto reactive sites. Therefore, an innovatively revised kinetics of the Cr(VI) removal by dispersant modified NZVI were provided and followed well. More importantly, Pluronic F-127 can be easily biodegraded after being released into environment with FNZVI. Given an excellent performance for removal of Cr(VI), the environmentally friendly micelles Pluronic F-127 modified NZVI represents an effective way for the remediation of Cr(VI) pollution.