工业铁屑(零价铁)还原硝基苯影响因素研究

通过静态试验,研究了初始硝基苯浓度、零价铁含量和pH值对零价铁还原硝基苯的影响.结果表明,在pH值为7,硝基苯初始浓度为311.25mg/L条件下,零价铁含量分别是100、50和25g/L时,硝基苯的降解速率常数分别是-0.02991、-0.0165和-0.00783min-1,零价铁含量越大硝基苯的降解速率越大;在pH值为7,零价铁含量为50g/L条件下,硝基苯的初始浓度分别是127.5,311.25,467.01mg/L时,硝基苯的降解速率常数分别是-0.01532、-0.01235和-0.00891min-1;在硝基苯初始浓度为311.5mg/L,零价铁含量为50g/L条件下,pH值为2.94时,硝基苯的降解速率最大,pH值为7其次,pH值为11.89时的降解速率最小,酸性环境利于零价铁还原硝基苯的进行.由此可见,硝基苯浓初始浓度、零价铁含量和pH值对硝基苯的还原具有重大影响.

Study on the reduction of nitrobenzene by industrial iron (zero-valent iron)

The effects of NB(nitrobenzene) concentration,ZVI(zero-valent iron) concentration and pH on the reduction of NB by ZVI were studied.The results showed that,the degradation rate constants of NB were-0.02991,-0.0165 and-0.00783 for 100,50 and 25g/L ZVI contained system respectively under the conditions of NB concentration 311.25mg/L and pH 7.When the concentration of ZVI was 50g/L and pH 7,the degradation rate constants of NB were-0.01532、-0.01235 and-0.00891 for 127.5,311.25 and 467.01mg/L NB contained system respectively.When the initial concentration of NB was 311.5mg/L and the concentration of ZVI was 50g/L,the maximum degradation efficiency of NB appeared at the pH 2.94.The minimum degradation efficiency of NB appeared at the pH 11.89.It is suggested that the acidic environment was not conductive to the reduction reaction.Therefore,the initial concentration of NB,the ZVI content and pH had significant impact on the reduction of NB.