Effect of hydroxyl radical oxidizing systems on formation of NDMA in the simulated system

To understand the effect of hydroxyl radical oxidizing systems on the formation of N - nitroso -dimethylamine (NDMA) . The effect on the reaction of sodium nitrite (NaNO2) and dim ethylamine (DMA) of different conditions including concentrations of H2O2and FeCl3, time and temperature were investigated. The results indicated that the content of NDMA decreased with the increase of H2O2 concentration, when the H2O2concentration was 5mmol/L, the inhibition ratio reached to 97. 5%. The effect of FeCl3on the NDMA content in the system may depend on the H2O2concentration. The content of NDMA was no significant change below 40℃, but the content of NDMA markedly increased at 80℃ (p<0. 01) . No significant effect of the concentration of H2O2 and FeCl3on the content of NDMA was observed. Or of the concentration of H2O2 and FeCl3 (p<0. 01) in the HRGS. The change of oxidation system conditions had significant effect on the formation of NDMA.