Excess nitrogen from agricultural and urban lands is contaminating groundwater, streams, lakes and estuaries, where it causes harmful algal blooms and contributes to fish kills. Cost-effective approaches to removing this nitrogen from croplands and urban stormwater runoff before it reaches sensitive water bodies have been elusive.

But simple and inexpensive technologies are on the horizon. A recent scientific workshop on denitrification brought together ecologists, engineers and policy experts to find answers.

Denitrification is a biological process carried out by soil and aquatic microorganisms, in which forms of reactive nitrogen are converted to unreactive and harmless dinitrogen gas.

Findings from the workshop, held in May, 2009, at the University of Rhode Island, are published in the November, 2010, special issue of the scientific journal Ecological Engineering.

The workshop was sponsored by the National Science Foundation (NSF)’s Denitrification Research Coordination Network (RCN), established to enhance collaboration among researchers investigating denitrification.

“This special issue of Ecological Engineering, with its focus on managing denitrification in human-dominated landscapes, highlights our need to understand Earth’s microorganisms and their processes,” says Matt Kane, program director in NSF’s Division of Environmental Biology, which funded the RCN and the workshop.

“The RCN brought together an international and interdisciplinary group of scientists and engineers to synthesize the knowledge necessary to provide pure water for generations to come.”

At the workshop, more than 40 participants combined their expertise to address the goal of using ecological principles in engineering design to control nitrogen pollution.

One workshop goal was to evaluate a new and relatively inexpensive way to treat wastewater and drainage from agricultural lands using “denitrifying bioreactors.”