title: Reduction of nitrate by NaY zeolite supported Fe, Cu/Fe and Mn/Fe nanoparticles.
abstract: Nano particles Fe, Cu/Fe and Mn/Fe supported on NaY zeolite (F@Y, CF@Y, and MF@Y) were prepared by two-step processes consisting of ion exchange and liquid-phase reduction. The characterization by XRD, SEM-EDX and BET-N2adsorption demonstrated that Fe, Cu/Fe and Mn/Fe nano particles were successfully loaded onto NaY zeolite and exhibited larger BET surface area compared to nano-Fe0(nZVI). Laboratory experiments showed that nitrate removal by metals@Y in unbuffered conditions reached nearly 100% at a dosage of 4g/L after 6h of reaction. Moreover, the nitrate removal was not sensitive to the initial solution pH. Even at a high pH of 9.0, metals@Y exhibited nitrate reduction above 94%. CF@Y demonstrated high N2selectivity, due to the high content of Cu (20wt%) and Fe (41wt%) in CF@Y and the highly active metallic sites on its surface with positive charge. Kinetic data showed a good fit to a first-order kinetic model during early reaction times. A close fit to both a second-order and an nth-order kinetic model was shown for the whole of the reaction period. The data suggest that both liquid phase mass transfer and the intrinsic reaction rate control the process of nitrate reduction by metals@Y.
authors.affiliation: Department of Civil Engineering, Stony Brook University, NY 11794, USA; School of Power and Mechanical Engineering, Wuhan University, Wuhan 430072, China.
authors.forename: Yubin
authors.initials: Y
authors.lastname: Zeng
authors.affiliation: Department of Civil Engineering, Stony Brook University, NY 11794, USA. Electronic address: harold.walker@stonybrook.edu.
authors.forename: Harold
authors.initials: H
authors.lastname: Walker
authors.affiliation: School of Marine and Atmospheric Sciences, Stony Brook University, NY 11794, USA.
authors.forename: Qingzhi
authors.initials: Q
authors.lastname: Zhu
keywords: Bimetallic nano particle; NaY zeolite; Nitrate reduction; Reaction kinetics