| Title |
Effect of pH on UV Photodegradation of N-Nitrosamines in Water |
| Authors |
심재구 ( Jae-goo Shim ) ; 아프잘아킬 ( Afzal Aqeel ) ; 최보미 ( Bo-mi Choi ) ; 이정현 ( Jung-hyun Lee ) ; 곽노상 ( No-sang Kwak ) ; 임호진 ( Ho-jin Lim ) |
| DOI |
https://doi.org/10.15681/KSWE.2016.32.4.357 |
| Keywords |
Nitrosamine; pH effect; Photodegradation; UV photolysis; Water treatment |
| Abstract |
N-nitrosamines are a class of carcinogenic chemicals that can pose significant hazards to the human life. Ultraviolet (UV) light irradiation is considered as one of the effective methods to reduce N-nitrosamines in the aqueous phase. This study aimed to investigate the pH influence on UV photodegradation of N-nitrosamines (i.e., N-nitrosodibutylamine (NDBA) and N-nitrosopyrrolidine (NPYR)) closely related to water treatment. Photodegradation rate constants of NDBA and NPYR remained between 3.26×10-2 L/W-min to 5.08×10-3 L/W-min and 1.14×10-2 L/W-min to 2.80×10-3 L/W-min at pH2-10, respectively. This study also focused on the formation of oxidized products (i.e., primarily NO2- and NO3-). Under slightly acidic and eutral conditions, NO2- formation was more prevalent than NO3- formation, while under strong acidic conditions, NO3- was more prevalent. There was no significant change in total organic carbon (TOC) and total nitrogen (TN), suggesting negligible loss of N-nitrosamines and degradation products from the system. NDBA was easily photodegraded than NPYR. This study also demonstrated that a lower pH is a favorable condition for photolytic degradation of N-nitrosamines in water. |