模拟地下水中重碳酸盐浓度对零价铁还原硝基苯的影响

通过静态试验研究了重碳酸盐浓度在0,100,300,500,800mg/L时对零价铁还原硝基苯的影响,检测反应过程中硝基苯和苯胺的浓度变化,同时检测溶液中pH值、Eh、Fe2+、CO32-的变化,结果表明,重碳酸盐浓度较低(100~500mg/L)时对零价铁还原硝基苯有促进作用,且促进作用随着重碳酸盐浓度的升高而增强.重碳酸盐浓度为500mg/L的反应体系中硝基苯去除率及苯胺生成率最高分别为88%,173mg/L,且在该体系中重碳酸盐对pH值的缓冲能力最强、Eh下降幅度最大,Fe2+浓度最高.重碳酸盐浓度为800mg/L的体系不利于硝基苯的还原.

Effects of different bicarbonate concentrations on the reduction of nitrobenzene by zero-valent iron in simulated groundwater

Batch experiments were designed to investigate the influence of different concentrations (0, 100, 300, 500 and 800mg/L) of bicarbonate on nitrobenzene degradation by zero valent iron in subsurface environment. The concentrations of nitrobenzene and aniline were monitored at interval time during the reaction progress, and the variations of pH, Eh, Fe2+, CO32- during the reaction were examined. The results indicated that bicarbonate can enhance the zero-valent iron activity at lower concentration (100~500 mg/L), and as the increasing of bicarbonate concentration, the promoting effect increases. in 500 mg/L system, the highest nitrobenzene reduction was 88% and aniline formation was 173 mg/L, the buffering capacity for pH was the strongest, the decline range of Eh was the largest, and the concentration of Fe2+ was the highest. The system of bicarbonate concentration of 800 mg/L was not conducive to the reduction of nitrobenzene.