纳米零价铁去除水中微量N-亚硝基二甲胺的研究

采用纳米零价铁催化降解水中微量N-亚硝基二甲胺(NDMA),并研究了溶解氧、纳米铁投加量、NDMA初始浓度、初始pH值、温度对纳米铁降解NDMA的影响.结果表明,纳米铁可以在中性厌氧条件下有效降解NDMA,作用效果远胜于普通铁粉;其对NDMA的去除速率随着纳米铁投加量的增加而增大,但与NDMA初始浓度无关;pH值降低或温度升高均有利于NDMA的降解.纳米铁降解NDMA存在一个启动期,启动期的长短与pH值和反应温度有关,提前活化纳米铁能有效提高反应速率.NDMA的降解产物主要是DMA和NH4+,其他产物如UDMH需进一步确认.

Removal of trace n-nitrosodimethylamine using nanoscale zero-valent iron

Removal of trace N-Nitrosodimethylamine (NDMA) using nanoscale zero-valent iron (NZVI) was studied as a potential technology. Effects of dissolved oxygen, initial concentration of NZVI, initial NDMA concentration, pH and temperature on the degradation of NDMA was investigated. NDMA was effectively removed by NZVI from deoxygenated solution under neutral condition, while the removal of NDMA was limited using common commercial iron powders. The removal rate increased with the increase of initial NZVI dosage, while the effect of initial NDMA concentration is not remarkable. Lower pH and higher temperature facilitated the reduction of NDMA with NZVI. There existed a lag period for the reduction of NDMA and the lag time was influenced by pH and temperature. When NZVI was pre-activated in water for 12h, the removal rate of NDMA was sharply improved. The main degradation products were DMA and NH4+; other products, such as UDMH, need further investigation.