New study outlines economic and environmental benefits to reducing nitrogen pollution

Jul 29, 2011

A new study co-authored by Columbia Engineering professor Kartik Chandran and recently published in the journal, Environmental Science & Technology, shows that reducing nitrogen pollution generated by wastewater treatment plants can come with "sizable" economic benefits, as well as the expected benefits for the environment.

Chandran was one of five scientists from around the U.S. who worked on the study, along with James Wang of NOAA's Air Resources Laboratory and formerly of Environmental Defense Fund (EDF); Steve Hamburg, Chief Scientist for EDF; Donald Pryor of Brown University; and Glen Daigger of CH2M Hill, a global environmental engineering firm based in Englewood, Colorado.

The study found that adding available technology to the existing infrastructure at a common type of wastewater treatment plant could create a trifecta of reductions in aquatic , greenhouse gas pollution, and energy usage. It also found that creating an emissions crediting system for the wastewater treatment sector could make the addition of new technologies much more affordable.

"As wastewater permits on wastewater become more and more restrictive, the resultant increased capital and operating costs can pose quite a burden to utilities and municipalities," said Chandran, associate professor of earth and environmental engineering. "Our study shows that, if the reduced emissions associated with well-designed and operated biological nitrogen removal operations can be used to earn CO2 credits, then this could be a big benefit both for the utilities from a cost perspective and for the environment from water quality and air quality perspectives."

The majority of wastewater treatment plants already have systems to reduce ammonia levels in effluent, but pay relatively little attention to overall nitrogen pollution reduction, especially in the form of nitrous oxide (N2O), a potent greenhouse gas. Using emissions credits to address the problem could create an economic incentive of up to $600 million per year for U.S. plants to reduce nitrogen pollution, with the added benefit of up to $100 million per year in electricity savings if they do so.

"Recent N2O monitoring studies conducted by Columbia Engineering and research groups across the globe have found that meeting wastewater treatment objectives actually decreases biogenic N2O emissions," added Chandran. "So designing and adopting better process technologies for improving water quality could actually have a significant impact on reduced N2O emissions."

"Our study shows that there's a win-win-win situation out there waiting to be realized," said James Wang, the chief author of the paper. "The creation of an emissions trading market could provide the needed incentive for wastewater treatment plants to adopt technologies that would reduce climate pollution, help clean up our waterways, and even save energy and money."

Chandran's research focuses primarily on biological nitrogen removal from wastewater, sustainable water sanitation and hygiene (WASH), and developing new technologies for resource recovery and reuse from waste. His team recently created the first protocol to measure nitrous oxide (a greenhouse gas 300 times more potent than CO2). Using the protocol, his Columbia Engineering group developed the first nationwide database of N2O emissions from wastewater treatment plants. The database has now been adopted by the U.S. Environmental Protection Agency as the standard to estimate N2O emissions from wastewater treatment plants. Chandran is also working towards developing and implementing "energy-positive" wastewater treatment technologies that will produce energy rather than consume it at some of the largest wastewater utilities in the U.S.

Chandran was recently awarded a $1.5 million project grant from the Bill & Melinda Gates Foundation to develop a revolutionary new model in water, sanitation, and energy. Working with his partners Dr. Ashley Murray, founder and director of Waste Enterprisers, and Dr. Moses Mensah, a chemical engineering professor at Kwame Nkrumah University of Science and Technology, Chandran is developing an innovative technology to transform fecal sludge into biodiesel and create the "Next-Generation Urban Sanitation Facility" in Accra, Ghana.

Explore further: Green dream: Can UN summit revive climate issue?

add to favorites email to friend print save as pdf

Related Stories

Nitrous oxide: definitely no laughing matter

Feb 18, 2008

Farmers, food suppliers, policy-makers, business leaders and environmentalists are joining forces to confront the threat of the ‘forgotten greenhouse gas’ by taking part in an influential new forum at the University of ...

Wastewater: Energy of the future?

Nov 14, 2005

Professor Jurg Keller at Australia's University of Queensland said he and his colleagues have discovered how to turn wastewater into electricity.

Household sewage: Not waste, but a vast new energy resource

Jan 05, 2011

In a finding that gives new meaning to the adage, "waste not, want not," scientists are reporting that household sewage has far more potential as an alternative energy source than previously thought. They say the discovery, ...

New China pollution targets inadequate: Greenpeace

Jan 17, 2011

Environmental group Greenpeace on Monday praised China for setting new pollution targets but said the measures fell well short of what was needed to curb the country's world-beating carbon emissions.

Recommended for you

Green dream: Can UN summit revive climate issue?

18 hours ago

Five years ago, the environment movement was in its heyday as politicians, actors, rock stars and protestors demanded a looming UN summit brake the juggernaut of climate change.

Rio's Olympic golf course in legal bunker

Sep 18, 2014

The return of golf to the Olympics after what will be 112 years by the time Rio hosts South America's first Games in 2016 comes amid accusations environmental laws were got round to build the facility in ...

User comments : 0