College of Environmental Science and Engineering, Taiyuan University of Technology, Taiyuan, Shanxi, PR China 030024.
College of Environmental Science and Engineering, Taiyuan University of Technology, Taiyuan, Shanxi, PR China 030024.
Ecotoxicol Environ Saf. 2021 Jan 1;207:111572. doi: 10.1016/j.ecoenv.2020.111572. Epub 2020 Nov 4.
In this work, green tea extracts synthesized nanoscale zero-valent iron/nickel (GT-nZVI/Ni) was prepared and the Cr(VI) contaminated soil column was remediated by GT-nZVI/Ni suspension. The influence factors including the concentration, pH value and flow rate of GT-nZVI/Ni suspension were studied. Under the conditions of pH = 4, concentration of 0.15 g/L and flow rate of 1.25 mL/h, GT-nZVI/Ni suspension had the best reduction and immobilization effect on Cr(VI) in the soil column. Na and Ca can promote the immobilization of Cr (VI) in soil, while humic acid weakened the immobilization of Cr (VI). After GT-nZVI/Ni is injected into the soil column, the content of weak acid extractable and reduced chromium is significantly reduced, and the toxic hazard of hexavalent chromium in the soil is greatly reduced. The 1D-CDE model was used to fit the breakthrough curves of Fe(tot), Fe(aq) and Fe(0), and the migration of GT-nZVI/Ni in Cr(VI) contaminated soil was simulated and predicted. Compared with the inert solute Cl, the breakthrough curves of Fe (tot), Fe (aq) and Fe (0) in Cr (VI) contaminated soil column were significantly lagged, with delay coefficients of 2.465, 2.322 and 3.288, respectively. The reaction of GT-nZVI/Ni with Cr (VI) led to the decrease of Fe mobility. Finally, the outflow concentration of Fe (tot) was 0.064 g/L, and the loss was mainly due to reaction and retention in the soil. About 57.89% of GT-nZVI/Ni was retained in the soil.
在这项工作中,制备了绿茶提取物合成的纳米零价铁/镍(GT-nZVI/Ni),并通过 GT-nZVI/Ni 悬浮液修复了 Cr(VI)污染的土壤柱。研究了 GT-nZVI/Ni 悬浮液的浓度、pH 值和流速等影响因素。在 pH=4、浓度为 0.15g/L 和流速为 1.25mL/h 的条件下,GT-nZVI/Ni 悬浮液对土壤柱中 Cr(VI)的还原和固定效果最好。Na 和 Ca 可以促进 Cr(VI)在土壤中的固定,而腐殖酸则削弱了 Cr(VI)的固定。GT-nZVI/Ni 注入土壤柱后,弱酸提取态和还原态铬的含量明显降低,土壤中六价铬的毒害作用大大降低。采用 1D-CDE 模型拟合 Fe(tot)、Fe(aq)和 Fe(0)的穿透曲线,模拟和预测 GT-nZVI/Ni 在 Cr(VI)污染土壤中的迁移。与惰性溶质 Cl 相比,Cr(VI)污染土壤柱中 Fe(tot)、Fe(aq)和 Fe(0)的穿透曲线明显滞后,延迟系数分别为 2.465、2.322 和 3.288。GT-nZVI/Ni 与 Cr(VI)的反应导致 Fe 迁移性降低。最后,流出液中 Fe(tot)的浓度为 0.064g/L,损失主要是由于在土壤中的反应和保留。约 57.89%的 GT-nZVI/Ni 被保留在土壤中。