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ARS Home » Southeast Area » Florence, South Carolina » Coastal Plain Soil, Water and Plant Conservation Research » Research » Publications at this Location » Publication #396073
Research Project: Innovative Manure Treatment Technologies and Enhanced Soil Health for Agricultural Systems of the Southeastern Coastal Plain

Location: Coastal Plain Soil, Water and Plant Conservation Research

Title: Optimization of total nitrogen removal rate in one-stage reactor through partial nitrification anammox process during direct treatment of poultry litter wastewater

Author
item XIAO, YITING - University Of Arkansas
item ZHAN, YUANHANG - Chinese Academy Of Agricultural Sciences
item ZHU, JUN - University Of Arkansas
item Vanotti, Matias

Submitted to: Journal of the ASABE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/25/2023
Publication Date: 1/31/2023
Citation: Xiao, Y., Zhu, J., Vanotti, M.B. 2023. Optimization of total nitrogen removal rate in one-stage reactor through partial nitrification anammox process during direct treatment of poultry litter wastewater. Journal of the ASABE. 66(2)/403-414. https://doi.org/10.13031/ja.15019.
DOI: https://doi.org/10.13031/ja.15019

Interpretive Summary: Poultry is one of the most commonly produced livestock in the United States. The total number of broilers produced in the U.S. each year is 9.18 billion annually, which generates14 million tons of poultry litter. Poultry litter can be used as a source of renewable energy through anaerobic digestion, but the high nitrogen content would inhibit the process. Therefore, to increase the efficiency for anaerobic digestion, or simply for the safe disposal of the treated wastewater, nitrogen in the poultry litter wastewater needs to be reduced. Anammox is an increasingly common process used for the treatment of municipal wastewater due to its low oxygen demand and limited carbon requirement that can save up to 90% of the operating cost of wastewater treatment. However, anammox is not commonly utilized in the direct treatment of poultry litter because of the high organic content, which would inhibit the anammox process. In this research, a one-stage partial nitrification and anammox (PN/A) process was developed and optimized for eliminating total nitrogen content in poultry litter. The bio-reactors were inoculated with anammox bacteria Brocadia caroliniensis and high performance nitrifiers (HPNS) provided by the USDA-ARS. Variables in the process included carbon to nitrogen ratio (C/N), dissolved oxygen level (DO), and hydraulic retention time (HRT). Central Composite Design coupled with Response Surface Methodology was used for optimizing the removal rate of total nitrogen (TN). The results showed that the anammox process applied to the nitrogen-rich poultry litter could achieve optimal TN removal rates of 87.3% when C/N, DO, and HRT equaled 1, 0.5 mg/L, and 72 hours, respectively, and that the quadratic regression model developed could sufficiently predict the nitrogen removal efficiency of the anammox process.

Technical Abstract: Anammox is an increasingly common process used for the treatment of reject water and even mainstream wastewater due to its low oxygen demand. However, anammox is not commonly utilized in the direct treatment of poultry litter because of the high organic content, which would inhibit the anammox process. A one-stage partial nitrification and anammox (PN/A) process was developed and optimized for eliminating total nitrogen content in poultry litter. Independent variables including carbon to nitrogen ratio (C/N) at 1, 2, and 3, dissolved oxygen level (DO, mg/L) at 0.2, 0.35, and 0.5, and hydraulic retention time (HRT, h) at 24, 48, and 72 were chosen and examined. Central Composite Design (CCD) coupled with Response Surface Methodology (RSM) was used for optimizing the removal rate of total nitrogen (TN). Results showed that in direct treatment of poultry litter, the one-stage PN/A process could achieve an optimal TN removal rate of 87.3% when C/N, DO, and HRT equaled 1, 0.5 mg/L, and 72 h, respectively. The quadratic regression model developed (p = 0.0018) could sufficiently predict the nitrogen removal efficiency of the sequencing batch biofilm reactor (SBBR). The uncertainty analysis showed an error range of from 0.33% to 2.81% for the model's accuracy of prediction within the DO, C/N ratio, and HRT ranges examined. The bacterial consortium analysis suggested that the successful control of the growth of ammonium oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) was achieved.