Removal of N-nitrosodimethylamine by ultraviolet treatment and anodizing TiO2 membrane processes



N-Nitrosodimethylamine (NDMA) is a disinfectant by-product shown to be carcinogenic, mutagenic, and teratogenic. The objective of this study is to compare NDMA removal efficiencies in water using conventional technologies (microfiltration, nanofiltration, reverse osmosis, and UV treatment) and innovative hybrid technology, which combines UV treatment with anodizing TiO2 membrane (UV/A-Ti-M) technology. In the UV/A-Ti-M photoreaction, the affecting factors such as UV intensity, the initial concentration of NDMA, and initial pHs were investigated. Even though membrane processes were ineffective in removing NDMA compounds, UV irradiation used in combination with an anodizing TiO2 membrane were achieved to remove NDMA completely from water. When NDMA was decomposed by UV/A-Ti-M process, dimethylamine yield increased and methylamine yield decreased with an increase in initial NDMA concentration. The successful removal of NDMA was specific to acidic conditions (pH 4–6). UV/A-Ti-M process is useful and powerful tools to remove NDMA in water. © 2011 American Institute of Chemical Engineers Environ Prog, 2011