Removal of Hexavalent Chromium [Cr (VI)] from Spiked Soil Using Na Y (Nano Sodium) Zeolite Supported Zero Valent Iron Nanoparticles

摘要

Soil remediation by nanoparticles has received increasing interests in recent years. The present work was conducted to investigate the feasibility of using new class of NC1 (Zeolite with ZVI nanoparticles) and NC2 (Na Y zeolite with ZVI nanoparticles) for In situ reductive immobilization of Cr (VI) in spiked soil. The spiked soil sample was subjected to XRD for the determination of crystallinity and average particle size. The size of the particle is 11.28 nm. The morphology of the nanoparticles was observed using SEM and FTIR. Batch experiments reported that the extend of Cr(VI) reduction was increased with increasing concentration of iron nanoparticles and inversely with initial Cr (VI) concentration as well as with decreasing pH (4 - 9). The efficiency of nanocomposites for Cr (VI) reduction was assessed in batch experiment and the results revealed that the rate of Cr (VI) reduction as a function of time showed a rapid reduction, it required 120 min to attain equilibrium for Cr (VI) reduction in NC2 and NC1 for spiked soil. In spiked soil, the maximum Cr (VI) reduction was achieved at an initial concentration of 200 mg kg-1 in pH 5 with 6 mg kg-1 of NC1 dosage whereas, 4 mg kg-1 dosage for NC2. This study indicates that the zerovalent iron nanoparticles, especially those which were Na Y zeolite supported ZVI nanoparticles can yield high removal efficiency in the reduction of Cr (VI) spiked soil.