Formation, Detection and Removal of NDMA in Water Treatment Process
N-Nitrosodimethylamine(NDMA) is known as a carcinogenic and mutagenic compound ,and in recent years, it has been found to be a novel disinfection by-product of the chloramination process.The NDMA precursors are considered as dimethylamine(DMA) and tertiary amines with dimethylamine functional groups. There are four pathways to NDMA formation: nitrosation, unsymmetrical dimethylhydrazine(UDMH) oxidation, chlorinated UDMH oxidation and hydroxylamine pathway. Formation of NDMA is affected by the presence of free chlorine and bromide, and pH is also a sensitive fator.The detection and analytical methods of NDMA are usually spectrophotometry，thin-layer chromatography, GC, LC and GC/MS.To improve the detection precision, GC/MS/MS and GC/HRMS are applied in detecting the trace NDMA. The methods of NDMA removal are UV degradation, the resin and several types of zeolite adsorption, UV/ozone and UV/hydrogen peroxide advanced oxidation technologies. Ozone also can oxidate percursors,so it can control the NDMA yield indirectly.
Zhenyu Du and X.B Sun
A. Li et al., "Formation, Detection and Removal of NDMA in Water Treatment Process", Advanced Materials Research, Vols. 113-116, pp. 1402-1406, 2010