title: N-nitrosodimethylamine and trihalomethane formation and minimisation in Southeast Queensland drinking water.
abstract: This study assesses the prevalence of disinfection by-product (DBP) precursors in some Southeast Queensland drinking water sources by conducting formation potential experiments for the four regulated trihalomethanes (THMs), and the potent carcinogen, N-nitrosodimethylamine (NDMA). NDMA formation potentials were consistently low (<5-21 ng/L), and total THM (tTHM) formation potentials were consistently below the Australian Drinking Water Guideline (250 μg/L). NDMA concentration of finished drinking waters was also monitored and found to be <5 ng/L in all cases. The effect of coagulation and advanced oxidation on the formation of NDMA and THMs is also reported. UV/H(2)O(2) pre-treatment was effective in producing water with very low THMs concentrations, and UV irradiation was an effective method for NDMA degradation. H(2)O(2) was not required for the observed NDMA degradation to occur. Coagulation using alum, ferric chloride or poly(diallyldimethylammonium chloride) (polyDADMAC) was ineffective in removing DBPs precursors from the source water studied, irrespective of the low dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) attained. Rather, coagulation with polyDADMAC caused an increase in NDMA formation potential upon chloramination, and all coagulants led to an increased tTHM formation potential upon chlorination due to the high bromide concentration of the source water studied.
authors.affiliation: Smart Water Research Centre, Griffith University, Southport, 4215, Queensland, Australia. n.knight@griffith.edu.au
authors.forename: Nicole
authors.initials: N
authors.lastname: Knight
authors.forename: Kalinda
authors.initials: K
authors.lastname: Watson
authors.forename: Maria José
authors.initials: MJ
authors.lastname: Farré
authors.forename: Glen
authors.initials: G
authors.lastname: Shaw
mesh_terms: D000498:Allyl Compounds / Q000737:chemistry; D001965:Bromides / Q000032:analysis / Q000737:chemistry; D004128:Dimethylnitrosamine / Q000032:analysis*; D004202:Disinfectants / Q000032:analysis*; D004203:Disinfection / Q000379:methods; D060766:Drinking Water / Q000737:chemistry*; D004784:Environmental Monitoring; D005618:Fresh Water / Q000737:chemistry; D054879:Halogenation; D009584:Nitrogen / Q000032:analysis / Q000737:chemistry; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D011793:Queensland; D022882:Trihalomethanes / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification / Q000379:methods*; D014881:Water Supply / Q000706:statistics & numerical data
chemical_list: D000498:Allyl Compounds; D001965:Bromides; D004202:Disinfectants; D060766:Drinking Water; D000644:Quaternary Ammonium Compounds; D022882:Trihalomethanes; D014874:Water Pollutants, Chemical; C508190:diallyldimethylammonium chloride; D004128:Dimethylnitrosamine; D009584:Nitrogen