Featured Research

from universities, journals, and other organizations

Monochloramine Treatment Not As Effective In Protecting Drinking Water

Date:
March 6, 2007
Source:
American Society for Microbiology
Summary:
The results of what may be the most extensive comparison of two common disinfectants used by municipal water systems suggest that, from a security standpoint, traditional chlorination may be more effective than treatment with monochloramine.

The results of what may be the most extensive comparison of two common disinfectants used by municipal water systems suggest that, from a security standpoint, traditional chlorination may be more effective than treatment with monochloramine.

"We have found something that is not necessarily a surprise but has important implications. These are considerations that water quality professionals should take into account if they have switched or are considering switching to a monochloramine disinfection system," says Dan Kroll, Chief Scientist at Hach Homeland Security in Loveland, Colorado, and lead researcher on the study, presented today at the ASM Biodefense and Emerging Disease Research Meeting.

As part of a recent endeavor to develop a system for online, continuous monitoring of drinking water distribution networks, Kroll and his colleagues, in coordination with the Army Corps of Engineers, studied the interactions of a wide variety of potential waterborne threat agents (both biological and chemical) with different levels of either free chlorine or monochloramine present. They tested dozens of potential hazards, from pesticides to disease-causing bacteria to chemical warfare agents.

The researchers discovered that not only is monochloramine less reactive than free chlorine against a number of chemical threats, it also is a slightly less efficient disinfectant, requiring a longer time to kill bacterial contaminants.

Scientists have long known that monochloramine is a more stable compound, and that is part of the reason it is becoming more popular as an alternative to chlorine in municipal water systems. Free chlorine has traditionally been the disinfectant of choice for municipal water systems throughout the 20th century, but it has some drawbacks. It can react with organic materials in drinking water to produce chlorine by-products. Some of these by-products are considered carcinogenic and their levels in drinking water are regulated by the U.S. Environmental Protection Agency.

But Kroll and his colleagues have confirmed in their study that the stability of the monochloramine may have its drawbacks as well. Treatment with free chlorine, because it is more reactive, can lead to rapid degradation of chemical threats as well as early detection of contamination. As it reacts with a contaminant, chlorine levels in the water drop. Many municipalities use chlorine levels as indicators of possible contamination.

Monochloramine also requires more time to kill microbial contaminants in water. This should not be an issue in treatment plants, as water in monochloramine facilities can be held longer. "In the event of contamination of the water supply after it leaves the treatment plant, though, monochloramine has the potential as being not as effective as chlorine, since there is little control over the contact time," says Kroll.

Kroll is not recommending that system that have already switched to monochloramine switch back. Instead, he wants water quality professionals to recognize that if they have a monochloramine system, they can no longer rely solely on a sudden drop in disinfectant levels to alert them to a potential contaminant. He also recommends that, where possible, some level of free chlorine should be kept in the system.

And if a municipality has a free chlorine-based system, provides water to a high-profile target such as a military base, and are considering the switch to monochloramine, they may want to consider other methods of controlling disinfection byproducts to help comply with EPA regulations.

"The findings in these studies have significant repercussions as to the safety and security of our nations water supplies," says Kroll.

The American Society for Microbiology (ASM) is the largest single life science society, composed of over 42,000 scientists, teachers, physicians, and health professionals. Its mission is to promote research and training in the microbiological sciences and to assist communication between scientists, policymakers, and the public to improve health, economic well-being, and the environment.

Further information on the ASM Biodefense and Emerging Disease Research Meeting can be found online at http://www.asmbiodefense.org.


Story Source:

The above story is based on materials provided by American Society for Microbiology. Note: Materials may be edited for content and length.


Cite This Page:

American Society for Microbiology. "Monochloramine Treatment Not As Effective In Protecting Drinking Water." ScienceDaily. ScienceDaily, 6 March 2007. <www.sciencedaily.com/releases/2007/03/070302082749.htm>.
American Society for Microbiology. (2007, March 6). Monochloramine Treatment Not As Effective In Protecting Drinking Water. ScienceDaily. Retrieved September 22, 2014 from www.sciencedaily.com/releases/2007/03/070302082749.htm
American Society for Microbiology. "Monochloramine Treatment Not As Effective In Protecting Drinking Water." ScienceDaily. www.sciencedaily.com/releases/2007/03/070302082749.htm (accessed September 22, 2014).

Share This



More Earth & Climate News

Monday, September 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Will Climate Rallies Spur Change?

Will Climate Rallies Spur Change?

Newsy (Sep. 21, 2014) Organizers of the People's Climate March and other rallies taking place in 166 countries hope to move U.N. officials to action ahead of their summit. Video provided by Newsy
Powered by NewsLook.com
Thousands March in NYC Over Climate Change

Thousands March in NYC Over Climate Change

AP (Sep. 21, 2014) Accompanied by drumbeats, wearing costumes and carrying signs, thousands of demonstrators filled the streets of Manhattan and other cities around the world on Sunday to urge policy makers to take action on climate change. (Sept. 21) Video provided by AP
Powered by NewsLook.com
Climate Change Rally Held in India Ahead of UN Summit

Climate Change Rally Held in India Ahead of UN Summit

AFP (Sep. 20, 2014) Some 125 world leaders are expected to commit to action on climate change at a UN summit Tuesday called to inject momentum in struggling efforts to tackle global warming. Duration: 00:41 Video provided by AFP
Powered by NewsLook.com
New Music With Recycled Instruments at Colombia Fest

New Music With Recycled Instruments at Colombia Fest

AFP (Sep. 19, 2014) Jars, bottles, caps and even a pizza box, recovered from the trash, were the elements used by four musical groups at the "RSFEST2014 Sonorities Recycling Festival", in Colombian city of Cali. Duration: 00:49 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins