细菌和颗粒浓度对纳米零价铁材料的柱迁移性影响

Effects of bacteria and particle concentration on column mobility of nanoscale zero-valent iron materials

通过填充柱实验研究了氢自养反硝化细菌(HB)和不同颗粒浓度对纳米零价铁(nZVI)和壳聚糖包覆纳米零价铁(CS-nZVI)在多孔介质中迁移的影响。利用穿透曲线考察了纳米零价铁材料的迁移性能。结果表明,颗粒浓度(0.2,0.5,1 g/L)对nZVI在多孔介质中的迁移性没有显著影响;CS-nZVI在低浓度(0.2 g/L)下有较好的迁移性。CS-nZVI在不同颗粒浓度下的穿透率均高于nZVI,显示出较好的迁移性能。纳米零价铁悬浮液中加入细菌,颗粒迁移性增强,其中1/3 HB条件下对nZVI和CS-nZVI迁移的促进作用更明显;细菌存在条件下,nZVI迁移性能随颗粒浓度增加而增强,而CS-nZVI的迁移性与颗粒浓度不呈正相关关系。

The effects of hydrogenotrophic bacteria(HB)and different particle concentrations on the transport and deposition of nanoscale zero-valent iron(nZVI)and chitosan-stabilized nanoscale zero-valent iron(CS-nZVI)in porous media were investigated by packed column experiments.The transport capability of nanoscale zero-valent iron materials were investigated by using the breakthrough curves.The results showed that the particle concentration(0.2,0.5,1 g/L)had no significant effect on the mobility of nZVI in porous media,and CS-nZVI had better mobility at low concentration(0.2 g/L).The breakthrough percentage of CS-nZVI at different particle concentration was higher than that of nZVI,showing better transport performance.When bacteria were added into nanoscale iron suspension,the mobility of materials was enhanced,and the transport of nZVI and CS-nZVI was more obvious under 1/3 HB;in the presence of bacteria,the migration of nZVI increased with the increase of particle concentration,while the migration of CS-nZVI was not positively correlated with particle concentration.