Effects of ozone and ozone/peroxide on trace organic contaminants and NDMA in drinking water and water reuse applications Aleksey N. Pisarenko a , Benjamin D. Stanford a,b , Dongxu Yan a,c,d , Daniel Gerrity a,e , Shane A. Snyder a,c, * a Southern Nevada Water Authority, Applied Research & Development Center, PO Box 99954, Las Vegas, NV 89193, USA b Hazen and Sawyer, P.C., Raleigh, NC 27607, USA c University of Arizona, Chemical and Environmental Engineering, Tucson, AZ, USA d Layne Christensen Company, 3804 E. Watkins Street, Phoenix, AZ 85034, USA e Trussell Technologies, Inc., 6540 Lusk Blvd., Suite C274, San Diego, CA 92121, USA article info Article history: Received 27 June 2011 Received in revised form 13 October 2011 Accepted 15 October 2011 Available online 25 October 2011 Keywords: N-Nitrosodimethylamine (NDMA) Trace organic contaminant (TOrC) Ozone Ozone/H 2 O 2 Ozone/peroxide Ozone/hydrogen peroxide Pharmaceuticals Endocrine disrupting compounds (EDCs) Advanced oxidation process (AOP) abstract An ozone and ozone/peroxide oxidation process was evaluated at pilot scale for trace organic contaminant (TOrC) mitigation and NDMA formation in both drinking water and water reuse applications. A reverse osmosis (RO) pilot was also evaluated as part of the water reuse treatment train. Ozone/peroxide showed lower electrical energy per order of removal (EEO) values for TOrCs in surface water treatment, but the addition of hydrogen peroxide increased EEO values during wastewater treatment. TOrC oxidation was corre- lated to changes in UV 254 absorbance and fluorescence offering a surrogate model for predicting contaminant removal. A decrease in N-nitrosodimethylamine (NDMA) forma- tion potential (after chloramination) was observed after treatment with ozone and ozone/ peroxide. However, during spiking experiments with surface water, ozone/peroxide ach- ieved limited destruction of NDMA, while in wastewaters net direct formation of NDMA of 6e33 ng/L was observed after either ozone or ozone/peroxide treatment. Once formed during ozonation, NDMA passed through the subsequent RO membranes, which highlights the significance of the potential for direct NDMA formation during oxidation in reuse applications. ª 2011 Elsevier Ltd. All rights reserved. 1. Introduction As the global population is projected to reach nine billion by 2050, water reuse and desalination will become a critical water resource for much of the world (Bereta and Miller, 2010). As such, ensuring adequate removal of trace organic contaminants (TOrCs) of health concern in reclaimed waters, including endocrine disrupting compounds (EDCs) and N- * Corresponding author. University of Arizona, Chemical and Environmental Engineering, 1133 E. James E. Rogers Way, Tucson, AZ 85721-0011, USA. E-mail address: snyders2@email.arizona.edu (S.A. Snyder). Available online at www.sciencedirect.com journal homepage: www.elsevier.com/locate/watres water research 46 (2012) 316 e326 0043-1354/$ e see front matter ª 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.watres.2011.10.021