USDA Agricultural Research Service (ARS) – Plains Area

Wastewater management is about to become a lot less smelly, a lot less toxic, and a lot less expensive thanks to technology developed by the Agricultural Research Service for swine farms that is also being adapted for household septic systems.

The odors associated with wastewater treatment are well known. A jury recently awarded more than $50 million to 10 neighbors of a swine farm in Bladen County, North Carolina, partly because of the foul smells coming from the farm’s open-air wastewater tanks, called lagoons. But swine lagoons aren’t just annoying; they’re also a public health hazard. In North Carolina, the Research Triangle Institute estimated that reducing gaseous emissions of ammonia from the state’s swine farms by 50% could save $189 million per year because of improvements in human health.

Both the high ammonia concentration typical in livestock wastewater and cold winter temperatures inhibit nitrification (conversion of ammonia to nitrite, which is soluble in water). Conventional methods of promoting nitrification, such as constructing additional treatment tanks or covering the lagoons with plastic, can be very expensive.

ARS scientists isolated a high-performance nitrifying sludge (HPNS) from manure that is effective at high ammonia levels and low temperatures. In addition to oxidizing the ammonia, the process substantially reduces the presence of odor-causing compounds in the wastewater.

The HPNS is introduced via floating media scaffolds, or capping units, which make it possible to treat just the top layer of wastewater rather than all of it. This process is significantly less expensive than the use of plastic lagoon covers or other conventional methods. Covering the lagoons in North Carolina alone would cost more than $320 million; the ARS lagoon capping units would cut that cost by more than half.

ARS signed technology transfer agreements with Pancopia Inc. of Hampton, Virginia, to design and develop next-generation commercial units of the technology, and with Terra Blue Inc. of Clinton, North Carolina, to devise cost-effective ways of retrofitting it for livestock production farms.

In addition to swine lagoons, the technology can be adapted to wastewater lagoons for other types of livestock such as dairy, beef and poultry. The technology transfer process also identified new market segments that could benefit from this technology, such as household septic systems.

Pancopia is planning to incorporate HPNS in household septic tanks in the Chesapeake Bay watershed, at a fraction of the cost of current systems. Maryland will pay up to $13,000 of the cost to replace a septic tank with one that will remove nitrogen; replacing the state’s 52,000 critical septic systems could require a $676 million investment. HPNS could cut that cost by two-thirds, saving up to $446 million.

This nomination details the successful partnership between a federal laboratory, university, collaborative sorghum stakeholder group, and a bioenergy industry partner to address an issue in bioethanol production and address barriers to adoption and utilization of sorghum—a crop in the United States that is more acclimated to growth in hotter/dryer climates.

The partnership identified a barrier to a grain processor, the biofuel plant, responding to the variability in local production of starchbased grains. Specifically, ethanol plants located on the Great Plains have influx between the availability of corn and sorghum based on the growing season. This necessitates the need to utilize diverse feedstock. A barrier to diversifying feedstock is the requirement to account for the grain in an infrastructure that mixes commodities in lieu of single commodity storage. Feedstock accounting supports both the management of fermentation efficiency and requirements of fuel markets. Addressing this barrier required high throughput technology that is scalable with easy adoption in a commercial processing plant.

Specifically, researchers at USDA Agricultural Research Service (ARS), Kansas State University, The Center for Sorghum Improvement and Western Plains Energy, LLC, collaborated to develop and validate a rapid near infrared (NIR) spectroscopic test to determine the composition of corn-sorghum flour mixtures used in the production of bioethanol. In addition to this rapid NIR test method, the partners developed a real-time PCR method to support the rapid NIR methodology with a reference and validation method.

Adoption of the NIR technology was rapid due to the integral partnership approach. Western Plains Energy, LLC, has received the NIR calibration curve and reference samples, and is integrating the methodology into operations. In addition, an NIR instrument company and a bioethanol enzyme company have received the NIR method and are working with Western Plains Energy to further implement and develop the methodology. This expansion of the partnership to service providers enables broader dissemination of the technology. Further distribution of the process will occur by publication and stakeholder presentation in the fall.

Western Plains Energy is currently in the process of adopting this technology for use and has installed in-line NIR instrumentation to facilitate it. This technology could be used industry-wide where needed to help identify the composition of feedstock used to produce a given batch of ethanol.

This project leveraged existing strong partnerships between the USDA-ARS lab in Manhattan, Kansas, Kansas State University researchers, and the Center for Sorghum Improvement at Kansas State University (state government). The interface between the researchers and industry provided by leadership at the Center for Sorghum Improvement was critical to the success of this project and highlights the potential for future partnerships between ARS, academia and the sorghum industry. Sorghum is an important crop for the central and southern region of the Great Plains, with an estimated gross production value for the U.S. of approximately $1.3 billion (www fao.org/faostat/en/#home). Continued partnerships like the one detailed in this nomination will serve to strengthen and increase the value of U.S. sorghum and benefit the U.S. ethanol industry.