利用绿茶提取液还原制备的纳米铁( GT2 NIP) 对水中六价铬具有良好的去除效果的原理, 通过向含水层中注 入 GT2NIP 可望实现六价铬在地下水中的原位去除, 但尚未得到验证。为此, 首先利用绿茶提取液还原法制备纳米 铁, 然后考察了其对水中六价铬的还原效果, 再利用柱试验研究 GT2NIP 对模拟地下水中六价铬的去除效果。结果 表明: 利用绿茶提取液制备的纳米铁为圆球形, 大小均匀, 直径约为 10~ 20 nm, 且分散性较好, 其中 Fe2+ 含量为 551 6% , Fe3+ 含量为 441 4% 。GT2NIP 悬浮液在水中对 Cr( ? ) 具有良好的降解能力, 当 GT2NIP 浓度为 11 0 g/ L 时, 反应 1 h, 初始浓度为 100 mg/ L 的 Cr( ? ) 去除率达到 961 8% ; 在柱试验中, GT2NIP 可以顺利穿透砂柱, 平均出 流百分比为 681 6% 。浓度为 100 mg / L 的 Cr( ? ) 溶液流过该纳米铁砂柱后, 流出液中 Cr3+ 浓度约为 01 20 mg / L, Cr6+ 浓度为 01 10~ 01 25 mg/ L, 即六价铬去除率达到 99% 以上。

Nano2iro n pr oduced by reductio n w ith g reen tea extr act ( GT2NIP) has g ood r emo val efficiency of hexav alent chromi2 um in w ater. It is ex pected that the remov al of hexav alent chr omium from gr oundw ater can be achieved in situ by injecting GT2 NIP into the aquifer; but this has not been verified yet. In this paper, we pr epar ed nano- ir on by reductio n w ith g reen tea ex2 tr act, measured its reductio n effect o n hex av alent chromium in w ater, and then used sand co lumn to study its remo val efficiency on hex avalent chromium in simulated g ro undw ater. The GT2NIP w e made w ere spherical and unifo rm in size, w ith a diameter of 10220 nm and g ood dispersion stability in w ater. They consisted o f 551 6% Fe2+ and 441 4% Fe3+ . When GT2NIP concent ratio n was 120 g/ L, after 1 h of r eact ion, the remo val rate of Cr( VI) w it h an initial concent ratio n o f 100 mg / L reached 9628% . In the co lumn test, GT2NIP could pass thro ug h the sand column, with an aver age outflow per centage o f 681 6% . When a Cr( ? ) so lu2 tion of 100 mg/ L was injected into t he sand co lumn, the concentrat ion of Cr 3+ w as abo ut 01 20 mg / L, and the concentr ation of Cr 6+ in the effluent was 01 10201 25 mg / L; that is, the to tal remo val r ate o f hex avalent chromium by GT2 NIP w as more than 99% .

中国地质科学院基本科研业务费项目( YYWF201629 ) ; 中国地质科学院水文地质环境地质研究所基本科研业务费项目 ( JYYWF201835) ; 河北省自然科学基金项目( D2017504004)