茶叶渣负载纳米铁的制备及对水溶液中酸性金黄G的去除

Preparation of tea residue supported nanoscale zero-valent iron and its removal of methanil yellow G from aqueous solution

采用硼氢化钠液相还原法制备纳米铁(nZ-VI)和茶叶渣负载纳米铁(TS60-nZVI),研究其对酸性金黄G(MYG)染料的脱色。结果表明,TS60-nZVI对MYG脱色比nZVI更好,脱色率达92.55%。SEM显示纳米铁经茶叶渣负载后提高了分散性,减少团聚;XRD表明TS60-nZVI与MYG反应后,其纳米Fe0的衍射峰消失,出现了铁氧化物和氢氧化物的衍射峰,说明反应过程纳米Fe0被氧化。动力学研究表明,TS60-nZVI对水溶液中的MYG还原遵循伪一级反应动力学,表观速率常数Kobs为6.0×10-3 min-1,半衰期为115.52min。

In this paper, nanoscale zero-valent iron（nZVI） and tea residue supported nanoscale zero valent iron（TS60-nZVI） was prepared using the sodium borohydride reduction method, and used it to remove the methanil yellow G（MYG） from aqueous solution. It was found that TS60-nZVI was more efficient in removal of MYG with 92. 55%. Furthermore, SEM showed that the tea residue as a supporter led to a decrease in aggregation of iron nanoparticles, the surface of TS60-nZVI was changed before and after used it to remove MYG, and XRD showed that the precipitation of iron oxide was observed. These indicate that Fe0 was oxidized during removal of MYG. In addition, kinetic study based on the experimental data indicated that the reaction fitted to pseudo first-order-model well and described with Langmuir-Hinshelwood kinetics equation, the apparent rate constants（Kobs） was 6. 0×10-3min-1 and half life was 115. 52min.