Water Innovations gives Water and Wastewater Engineers and end-users a venue to find project solutions and source valuable product information. We aim to educate the engineering and operations community on important issues and trends.
Issue link: http://wateronline.epubxp.com/i/628452
other site-specific characteristics are important considerations in determining dosing requirements for various wastewater types, in general, results of studies are demonstrating that, for secondary effluent, initial design dosing is 1.5 to 2 mg/L of PAA. And with the fast disinfection kinetics of PAA, there are case study projects being implemented with peak flow contact times significantly shorter than what is required for achieving bacterial inactivation compliance for chlorine. While PAA is seemingly a success story, PAA still faces a hurdle of limited use when compared to other more mature disinfection technologies such as chlorination, ozone, and UV disinfection. Though the EPA has approved four PAA products for use as a wastewater disinfectant, state regulatory agencies are struggling with how to address permitting. Some of these challenges are related to the fact that the EPA has yet to publish an "approved" method for PAA monitoring in the Code of Federal Regulations. Even considering the EPA has approved registration labels on allowable residuals for discharge, the office that is responsible for environmental toxicity decisions is not necessarily coordinated with the Office of Wastewater, making it difficult for states to obtain technical support to implement PAA projects. The information presented herein is intended to be a cursory overview of PAA disinfection. There is a tremendous amount of literature and experience with wastewater disinfection using PAA. To respond to the growing interest in this technology, it will be necessary to develop regulatory and design guidance to aid decision-makers in understanding the cost of compliance of using PAA as well as obtaining local regulatory support for implementation. Thus, when an individual facility is evaluating disinfection options, it is important to consider site-specific factors such as compliance goals, O&M; (operations and maintenance), the willingness of a particular facility to take on risks associated with implementation of a new technology, and costs. If considering PAA for disinfection, utilities are advised to discuss this option with their consulting engineer, local regulatory authorities, and local PAA sales representatives to obtain more information on how this alternative compares to other mature disinfection technologies. n 18 wateronline.com n Water Innovations About The Authors Dr. Kati Bell, PhD, PE, BCEE, is the Water Reuse Global Practice Leader for MWH Global. She is a registered engineer in four states with 20 years of experience in research, selection, design, and optimization of water/wastewater processes. Highlights of her work include chairing the recently published WEF/IUVA Ultraviolet Disinfection Wastewater, as well as directing over 2 BGD of disinfection projects. Varsha Wylie is a Project Technical Lead for MWH Global. She is a process engineer with 13 years of international experience in the water industry. She has a strong design-build background and has designed and commissioned a number of water/wastewater treat- ment facilities in the UK and the U.S. DISINFECTIONBYPRODUCTS 1. US Environmental Protection Agency (EPA) 1976. Disinfection of Wastewater – Task Force Report. EPA-430/9-75-013, US Environmental Protection Agency, Washington, DC; Environment Canada 1978. Wastewater Disinfection in Canada. EPS 3-WP-78-4, Environmental Protection Service, Canada. 2. Riordan, C. 1979. Perspectives on Wastewater Disinfection – A View from Headquarters. Progress in Wastewater Disinfection Technology, Proceedings of the National Symposium EPA-600/9-79-018, United States Environmental Protection Agency, Cincinnati, OH, USA. 3. U.S. Environmental Protection Agency (EPA). 2012. Guidelines for Water Reuse. EPA/600/R-12/618. Environmental Protection Agency. Washington, D.C. 4. Zheng, A., D. A. Dzombak, et al. (2004). Effects of Thiocyanate on the Formation of Free Cyanide during Chlorination and Ultraviolet Disinfection of Publicly Owned Treatment Works Secondary Effluent. Water Environment Research. 76(3):205-212. 5. Buth, J.M., Steen, P.O., Sueper, C., Blumentritt, D., Vikesland, P.J., Arnold, W.A., and McNeill, K. (2010). Dioxin photoproducts of triclosan and its chlorinated derivatives in sediment cores. Environ. Sci. Technol. 44, 4545. 6. http://www.americanchemistry.com/Policy/Rail-Transportation/Issue-Brief-on- Chlorine-Rail-Transportation-Safety.pdf, accessed November 2015 7. Gallard, H., Leclercq, A., Croué, J.P. (2004). Chlorination of bisphenol A: kinetics and by-products formation. Chemosphere, 56(5):465-73. 8. Sumpter, J.P., Johnson, A.C., Williams, R.J., Kortenkamp, A., and Scholze, M. (2006). Modeling effects of mixtures of endocrine disrupting chemicals at the river catchment scale. Environ. Sci. Technol. 40(17), 5478 - 5489. 9. Deborde, M., Rabouan, S., Gallard, H., Legube, B. (2004). Aqueous chlorination kinetics of some endocrine disruptors. Environ. Sci. Technol. 38, 5577. Figure 4. Typical pump skid used for PAA feed. (Credit: PeroxyChem) Table 1. Chemical Information for PAA Products Registered for Wastewater Disinfection