关键词: 复合材料, 硝酸盐, 纳米Fe0, 纳米Fe/Cu, 纳米Fe/Ni, 脱硝

Abstract: Nanoscale Fe0, Fe/Ni and Fe/Cu particles were synthesized respectively using liquidphase reduction method. Then these nanoparticles were studied as reactive materials for the reduction of nitrate in groundwater under anaerobic condition. The factors affecting the reduction of nitrate, such as the reactive material, the loading content and the initial nitrate concentration in the water, were investigated. Experiments were carried out to examine the mechanisms and productions of contaminant degradation by the three types of nanoparticles. Results show that the Fe/Cu nanoparticles with 5.0% Cu can significantly enhance the rate of reduction of nitrate, remove almost 100% nitrate within a period of 20 min when the iron concentration was 1.5 g/L. In the progress, nitrate removal was accompanied with NH+4 N increase and NO-2 N undergo the process of from increasetodecrease, with final nitrogen loss in the reaction of about 25%. Experiments results also show that the activity and selectivity of bimetallic Fe/Cu to a benign compound (i.e., nitrogen gas) is comparable to that of ironbased bimetals (Fe/Ni) and zerovalent metals. The ammonium of the denitrification by nanoscale Feo and Fe/Ni is above 95%. Bimetallic Fe/Cu could be a promising reactive reagent for the reduction of nitrate.

Key words: composite material, nitrate, nanoscale Fe0, nanoscale Fe/Ni, nanoscale Fe/Cu, denitrification