Reduction of N-Nitrosodimethylamine (NDMA) in Aqueous Solution by Nanoscale Fe/Al₂(SO ₄) ₃
2013
Lin, Lin | Xu, Bin | Lin, Yi-Li | Yan, Lie | Shen, Kai-Yuan | Xia, Sheng-Ji | Hu, Chen-Yan | Rong, Rong
N-Nitrosodimethylamine (NDMA) is recently defined as one of nitrogenous disinfection by-products with high carcinogenicity and can be frequently detected in finished water. The decomposition of NDMA in water using nanoscale zero-valent iron (NZVI) in the presence of aluminum and iron salts was investigated in this paper. The results showed that some salts can enhance the removal of NDMA by commercial NZVI in the order of Al(SO) >> AlCl > FeSO > NaSO ≈ NZVI alone, and the highest NDMA removal was 87.3 % in the presence of Al(SO). NDMA removal varied with the addition of Al(SO), NZVI dosage, initial NDMA concentration, solution pH, and temperature. The reduction of NDMA increased with the dosage of Al(SO) and NZVI, which follows a pseudo-first-order kinetics model. The removal of NDMA by NZVI was higher in acidic pHs than in alkaline ones, and the highest removal was found at pH 5. Higher reaction temperature can improve the removal of NDMA and reduce the reaction time. Based on the total nitrogen balance, most nitrogen of NDMA was converted to ammonium and dimethylamine.
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