UiO-66-NH_(2)/wood的设计构筑及高效去除水中微量重金属离子性能

Design and Construction of UiO-66-NH_(2)/wood Composite for Efficient Removal of Trace Heavy Metal Ions from Water

矿山开采、金属冶炼、新型金属材料的发展以及城市供水系统老化所造成的重金属(铅、镉、汞、砷、铬、铜及锌等)污染问题已日趋严重.传统的水处理方法很难有效地去除低浓度的重金属污染物.本文以天然木材为载体,采用溶剂热合成法,在木材三维孔道中原位合成UiO-66-NH_(2)金属有机框架材料(MOFs)纳米颗粒,制备了UiO-66-NH_(2)/wood复合膜材料.该复合膜材料对去除水中微量重金属离子(Hg^(2+),Cu^(2+))表现出优异的性能.当处理速率为1.1×10^(2)L·m^(-2)·h^(-1)时,该复合膜材料去除水中微量重金属离子的效率仍可达到90%以上,且处理后水中重金属离子含量低于国家饮用水标准.这可归因于木材本身独特的三维孔道结构,在提高水通量的同时,还可以增加水溶液中重金属离子与MOFs颗粒的接触机会,以及孔道内均匀分布的UiO-66-NH_(2)MOFs颗粒中的—NH_(2)可以与重金属离子通过配位作用相结合.该UiO-66-NH_(2)/wood复合膜材料还具有良好的重复利用性,在连续6次循环使用后其去除效率无明显变化,有望进行实际应用.

UiO-66-NH_(2) Metal-Organic-Frameworks(MOFs)nanoparticles were in situ formed in the 3D low-tortuosity wood lumens by a facile solve-thermal strategy with ZrCl^(2+) and amino terephthalic acid as precursors.The UiO-66-NH_(2)/wood membrane showed excellent removal performance for removing heavy metal ions(Hg^(2+),Cu^(2+)) in wastewater.The results showed that the removal efficiency for tested heavy metal ions(Hg^(2+),Cu^(2+)) is more than 90.0%at the treatment rate of 1.0×10^(2)L·m^(-2)·h^(-1).Wood membrane,as a 3D substrate for anchoring UiO-66-NH_(2) nanoparticles,contains numerous elongated and open lumens along the growth direction.On the one hand,it can enhance the water of including heavy metal ions fluxes^(2+) on the other hand,it can increase the contact probability of heavy metal ion containments with UiO-66-NH_(2)MOFs as water flowing through the membrane.Therefore,the UiO-66-NH_(2)/wood membrane can efficiently remove trace heavy metal ions from the water.In addition,the UiO-66-NH_(2)/wood membrane also has good reusability,which is expected to be applied in practical applications.