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Black & Veatch Corp., announced today the completion of groundbreaking research that has earned the 2005 Excellence in Environmental Engineering Grand Prize in Research from the American Academy of Environmental Engineers (AAEE) and the 2005 American Council of Engineering Companies of Massachusetts (ACEC/MA) Grand Conceptor Award, which is the highest distinction bestowed by ACEC/MA.
A collaborative team, jointly led by Black & Veatch and the University of New Hampshire (UNH) and including several water utilities and other universities, identified the sequential application of ozone followed by ultraviolet (UV) light as a cost-effective disinfection strategy to simultaneously inactivate waterborne pathogens and minimize disinfection byproducts.
To help utilities meet stringent U.S. Environmental Protection Agency (EPA) regulations that require higher levels of pathogen disinfection with lower levels of disinfection byproducts, Black & Veatch and UNH joined with other disinfection technology leaders in the tailored-collaboration research alliance. In a tailored collaboration, task and talent are matched to support timely research of interest to the participating utilities and the drinking water industry as a whole.
Sponsored and partially funded by the Awwa Research Foundation (AwwaRF), the "Evaluation of Ozone and Ultraviolet Light" was co-funded by the Massachusetts Water Resources Authority (MWRA); Town of Concord, Mass.; and Southern Nevada Water Authority. The Portland (Ore.) Water Bureau provided technical review. Research participants also included experts from the University of Arizona; University of Massachusetts; Tufts University; and Montana State University. Mitsubishi Electric Power Products, Inc. and Trojan Technologies Inc. contributed an ozone generator and three UV reactors, respectively.
"This project confirmed that ozone and UV in combination is a viable and cost-effective solution, provided hands-on operation experience with an ozone and UV facility, and yielded design guidance that will reduce the overall costs of the UV system," said MWRA Design Manager Tiffany Tran.
The project included several notable firsts. It was the first research project to examine disinfection effectiveness and disinfection byproducts of sequential treatments using ozone and UV and the first in the U.S. to conduct both pilot- and demonstration-scale research on ozone and UV.
The town of Concord is one of the first U.S. utilities to treat unfiltered water with ozone and UV light, the first to examine customer distribution system effects of ozone and UV using a real distribution system, and among the first in the world to implement this disinfection strategy at full scale by adding UV light to its ozone facility. MWRA built and operated the first and largest ozone and UV light demonstration facility using 200-gallon-per-minute pilot trains and pipe loop composed of 600 feet of pipe excavated from the streets of Boston, Mass.
Previous AwwaRF research established that UV is effective in Cryptosporidium and Giardia inactivation, which paved the way for both EPA endorsement of UV as a cost-effective treatment process and ensuing research. The recent award-winning research provided convincing evidence that combining the strengths of ozone for oxidation, taste and odor reduction, and virus inactivation; UV light for Cryptosporidium and Giardia inactivation; and chlorine or chloramines for bacterial inactivation and protection within the distribution system provided a cost-effective treatment strategy. The scheme yields a high degree of disinfection, lowers levels of harmful byproducts, and minimizes adverse distributed-water effects such as red water and bacterial regrowth. Additionally, the team learned that ozonation, by breaking down organic compounds, actually makes the water more amenable to UV light. As a result, ozonation prior to UV application could be expected to reduce capital costs of a new UV system by 20 percent and operating costs by 30%.
"The Excellence in Environmental Engineering competition of the American Academy of Environmental Engineers exists to identify and reward the best of today's innovative research and projects in the field," said AAEE Executive Director David A. Asselin. "The first-ever research to examine the sequential treatment of raw water with ozone and UV light is bound to produce results that will contribute to an improved water quality and economic efficiency for water utilities and the general public."