Water Journal : Water Journal July 2012
chlorine disinfection refereed paper technical features 70 JULY 2012 water model developed by Reckhow and Singer (1984). In their model, chlorination of fulvic acid solutions led to the formation of intermediate by-products, such as 1,1-DCP, that could be further oxidised by chlorine to 1,1,1-TCP. This model reveals that further chlorine attack and hydrolysis are essential for the formation of 1,1,1-TCP. Five iodinated-THMs (I-THMs) were also measured in this study. We did not find I-THMs above 3.5 μg/L, which is in concurrence with the measurements of iodide in the samples that were, in all instances, below the 0.01 mg/L limit of detection (LOD). Similarly, NDMA was not detected above the 5 ng/L LOD across the distribution system. NDMA formation potential of source water at the Capalaba WTP was 11.4 ± 3.4 ng/L (n=3), which is also well below the ADWG value (i.e., 100 ng/L). Conclusions All regulated DBPs were measured below ADWG values in all analysed samples across the Capalaba region. • THM speciation followed the order TCM>BDCM>DBCM>TBM in sampling points providing water from Capalaba and DBCM>BCDM>TBM>TCM in waters blended with NSI water as a result of different DOC/Br ratios. • HANs were measured at relatively high concentrations for locations serviced primarily by Capalaba WTP. Even though they were measured below WHO limits, we recommend investigating possibilities to control the formation of HANs at the drinking WTP as they are suspected to be more toxic than carbon-based regulated DBPs. The Authors Dr Maria José Farré (email: m.farre@awmc. uq.edu.au) is a Research Fellow at the Advanced Water Management Centre (AWMC), The University of Queensland, Brisbane, Australia. Her scientific interests are related to the formation and fate of disinfection by-products during the production and transportation of both drinking and recycled water. This study is part of a bigger project entitled "Assessment of Regulated and Emerging Disinfection By-Products in South East Queensland Drinking Water". Hollie King and Emmanuelle Filloux are research staff in this project at the AWMC. Jurg Keller and Wolfgang Gernjak are academic staff at the AWMC. Nicole Knight, Kalinda Watson and Fred Leusch are researchers at the Smart Water Research Centre (SWRC), Griffith University, Gold Coast, Queensland. Michael Bartkow is a researcher at Seqwater, Brisbane, Queensland, Brad Taylor is Group Manager Product Quality and Testing at Allconnex Water, Gold Coast, Queensland and Paul Burrell is Water Quality Coordinator at SEQ Water Grid Manager, Brisbane, Queensland. Acknowledgements This research is being conducted as part of the Urban Water Security Research Alliance (UWSRA), a collaboration between the Queensland Government, CSIRO, The University of Queensland and Griffith University. The authors wish to acknowledge Seqwater and Allconnex Water for giving access to the plants and assisting with the sampling. References Bond T, Huang J, Templeton MR & Graham N (2011): Occurrence and control of nitrogenous disinfection by-products in drinking water -- A review. Water Research, 45, pp 4341--4354. Bougeard CMM, Goslan EH, Jefferson B & Parsons SA (2010): Comparison of the disinfection by-product formation potential of treated waters exposed to chlorine and monochloramine. Water Research, 44, pp 729--740. Buffle MO, Galli S & Von Gunten U (2004): Enhanced bromate control during ozonation: The chlorine-ammonia process. Environmental Science & Technology, 38, pp 5187--5195. Croué JP & Reckhow DA (1989): Destruction of chlorination byproducts with sulfite. Environmental Science & Technology, 23, pp 1412--1419. Dabrowska A & Nawrocki J (2009): Controversies about the occurrence of chloral hydrate in drinking water. Water Research, 43, pp 2201--2208. Farré MJ, King H, Keller J, Gernjak W, Knight N, Watson K, Shaw G, Leusch FDL, Sadler R, Birt J, Bartkow M & Burrell P (2011): Disinfection By-Products in South East Queensland: Assessing Potential Effects of Transforming Disinfectants in the SEQ Water Grid. UWSRA Science Forum, Brisbane. Gallard H & Von Gunten U (2002): Chlorination of natural organic matter: Kinetics of chlorination and of THM formation. Water Research, 36, pp 65--74. Goslan EH, Krasner SW, Bower M, Rocks SA, Holmes P, Levy LS & Parsons SA (2009): A comparison of disinfection by-products found in chlorinated and chloraminated drinking waters in Scotland. Water Research, 43, pp 4698--4706. Kameya T, Hada T & Urano K (1997). Changes of adsorption capacity and pore distribution of biological activated carbon on advanced water treatment. Water Science and Technology, 35, pp 155--162. Figure 3. Average concentration and range of HANs in Capalaba WTP and distribution system. Figure 4. Average concentration and range of CH, TCNM, 1,1-DCP and 1,1,1-TCP in Capalaba WTP and distribution system.
Water Journal August 2012
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