利用海绵铁的还原性及其表面疏松多孔的特性,研究其转化地下水中硝酸盐的各项性能.通过静态试验研究了海绵铁粒径、固液比以及共存离子对硝酸盐转化效果的影响,对转化产物和溶出的总铁量进行分析,并通过动态试验研究了接触时间和进水NO3- -N浓度对硝酸盐转化的影响.结果表明:在pH为2.5时,海绵铁的粒径越小,硝酸盐的转化率越高；在一定范围内,增加固液比,有利于硝酸盐的转化,试验最佳的固液比(以每毫升硝酸钾溶液中投加海绵铁的质量计,g/mL)为1.0:25.0;溶液中存在的Cl-和SO24-在一定程度上对硝酸盐的转化有抑制作用.产物分析表明,NH4+-N是硝酸盐转化的主要产物,转化产物中NO2--N浓度很低,同时有一部分气体产生.动态试验表明,在试验条件下,最佳的接触时间为7.7 min；增加进水NO3- -N浓度,硝酸盐的转化率降低.%Experiment study was carried out to evaluated the performance of sponge iron in the conversion of nitrate in groundwater,due to its reductive and porous quality. The effects of particle size,solid-liquid ratio (S/L) and coexisting ions on nitrite conversion were investigated with the static experiment, and reaction products and gross ferric dissolution were analyzed and compared identically. Then,some running conditions,contact time and nitrate concentration of influent were researched in the nitrate conversion dynamic experiment. The results showed as follow the rate of nitrate conversion rose with the diminishing of the sponge iron particle increasing S/L was favorable to the nitrate conversion and the optimum S/L was 1. 0 : 25. 0;chloride ions and sulfate ions in water inhibited slightly the nitrate conversion. NH4+-N was the main product in all conversion species. The dynamic filter experiment showed that, the optimum reacting time is 7. 7 min,and the conversion rate decreased with increasing of the nitrate concentration in the influent.
展开▼
