硅化改性微米零价铁去除水体中镍离子

Removal of of Ni(II)from water using silicified micron zero-valent iron

以可溶性硅酸盐为前驱体,通过机械化学方法制备了一种新型硅化改性微米零价铁(Si-mZVI^(BM)),并将其用于含镍废水处理.结果表明,硅化改性可显著提升微米零价铁的除镍效能,相比于未改性微米零价铁,镍去除率提高了8倍,且在多种实际镍污染水体中修复效能优异.基于解析样品微观形貌、表面电负性及元素组成等特征发现,Si-mZVI^(BM)的优异除镍效能主要源于机械硅化加速微米零价铁颗粒细化;样品比表面积与分散性的提升促进了镍从溶液到材料表面的传质.同时,硅化还加速微米零价铁界面电子传输速率,促进表面吸附镍的快速还原与沉淀分离,进而实现镍的高效去除.

A novel silicified micron zero-valent iron(Si-mZVI^(BM))was prepared by mechanochemical method using soluble silicate as the precursor and the Si-mZVI^(BM) was applied to treat the nickel-containing wastewater.The results showed that the silicon modification can significantly enhance the nickel removal efficiency of micron zero-valent iron.Compared with the unmodified micron zero-valent iron,the nickel removal efficiency was increased by 8times.Furthermore,the Si-mZVI^(BM) showed excellent performances in a variety of actual nickel-polluted water bodies.Based on the microstructure,surface electronegativity and elemental composition analyses of the Si-mZVI^(BM),it was found that the excellent nickel removal performance of Si-mZVI^(BM) was mainly due to the accelerated refinement of micron zero-valent iron particles by mechanical siliconization.The increase of specific surface area and dispersibility of the Si-mZVI^(BM) promoted the mass transfer of nickel from solution to material surface.At the same time,the silicification also could accelerate the electron transport rate at the interface of micron zero-valent iron,which resulted in rapid reduction and precipitate separation of nickel adsorbed on the surface,and eventually realized the efficient removal of nickel.