Nitrogen Removal, N2O Emission, and NH3 Volatilization Under Different Water Levels in a Vertical Flow Treatment System
- 310 Downloads
Two series of laboratory-scale vertical flow systems (flooded and nonflooded columns) were designed to compare nitrogen removal performance, nitrous oxide emission, and ammonia volatilization under different water levels upon treating diluted digested livestock liquid. In these systems, influent was supplied at three hydraulic loading rates (HLRs of 1.25, 2.5, and 5 cm day−1) during stage 1 and the rates were doubled during stage 2 when the water levels of nonflooded columns were elevated from zero to half the height of the soil column. After hydraulic loading rates doubled, the average removal rates of total nitrogen in flooded columns varied from 1.27 to 2.94 g−2 day−1 and those in nonflooded columns ranged from 1.23 to 3.88 g−2 day−1. The T-N removal at an HLR of 10 cm day−1 in the nonflooded column with an elevated water table level had higher efficiency than that in the flooded column, suggesting T-N removal is enhanced in the nonflooded column probably due to the improved coupled nitrification–denitrification process under the elevated water table level condition. On the other hand, there was a significant correlation (r 2 = 0.532, p < 0.001) between the N2O flux and redox potential that mainly corresponded to water levels and HLRs, suggesting anoxic or aerobic conditions stimulate N2O emission by enhancing the nitrification (nitrification–denitrification) process. In contrast, NH3 volatilization had a high flux in the anaerobic condition mainly because of flooding. Based on the experimental results, it is hypothesized a nonflooded condition with higher water table level (Eh range of −160 to +260 mV) would be suitable to reduce N2O emission and NH3 volatilization peak value by at least half while maintaining relatively efficient nitrogen removal performance.
KeywordsAmmonia volatilization Digested livestock liquid Nitrification–denitrification Nitrous oxide emission Redox Wastewater treatment
This research was supported by a Grant-in-Aid for Scientific Research (Start-up; no. 19810003) from the Ministry of Education, Science, Sports and Culture, Japan. We would like to thank the anonymous reviewers for their constructive and critical suggestions and comments that made this paper more complete.
- Claire, E. M., Eric, P., Philippe, P., Peter, W., & Maritxu, G. (2008). Particle size and metal distributions in anaerobically digested pig slurry. Bioresource Technology (in press), DOI 10.1016/j.biortech.2007.05.013.
- Gambrell, R. P., & Patrick Jr., W. H. (1978). Chemical and microbiological properties of anerobic soils and sediments. In D. D. Hook, & R. M. M. Crawford (Eds.) Plant life in anaerobic environments. Ann Arbor, MI: Ann Arbor Science.Google Scholar
- Hunt, P. G., & Poach, M. E. (2001). State of the art for animal wastewater treatment in constructed wetlands. Water Science and Technology, 44(11–12), 19–25.Google Scholar
- Intergovernmental Panel on Climate Change (IPCC) (2001). The third assessment report, climate change 2001. UK: Cambridge University Press.Google Scholar
- Johansson, A. E., Klemedtsson, Å. K., Klemedtsson, L., & Svensson, B. H. (2003). Nitrous oxide exchanges with the atmosphere of a constructed wetland treating wastewater. Tellus, 55B, 737–750.Google Scholar
- Kadlec, R. H., & Knight, R. L. (1996). Treatment wetlands. Boca Raton, FL: Lewis.Google Scholar
- Mander, Ü., Kuusemets, V., Lohmus, K., Mauring, T., Teiter, S., & Augustin, J. (2003). Nitrous oxide, dinitrogen and methane emission in a subsurface flow constructed wetland. Water Science and Technology, 48, 135–142.Google Scholar
- Manly, B. F. J. (1992). The design and analysis of research studies. Cambridge: Cambridge University Press.Google Scholar
- Patrick, W. H., Gambrell, R. P., & Faulkner, S. P. (1996). Redox measurements of soils. In: Methods of soil analysis. Part 3. Chemical methods pp. 1255–1273. Madison, WI: Soil Science Society of America and American Society of Agronomy.Google Scholar
- Poach, M. E., Hunt, P. G., Reddy, G. B., Stone, K. C., Matheny, T. A., Johnson, M. H., et al. (2004). Ammonia volatilization from marsh–pond–marsh constructed wetlands treating swine wastewater. Journal of Environmental Quality, 33, 844–851.Google Scholar
- Roeloffs, J. G. L., & Houdijik, A. L. M. (1991). Ecological effects of ammonia. In V. C. Nielson, B. F. Pain, & J. Harting (Eds.) Ammonia and odour emission from livestock production (pp. 10–16). Barking, UK: Elsevier.Google Scholar
- Szögi, A. A., Hunt, P. G., Sadler, E. J., & Evans, D. E. (2004). Characterization of oxidation–reduction processes in constructed wetlands for swine wastewater treatment. Applied Engineering in Agriculture, 20, 189–200.Google Scholar
- Zhou, S., Nakai, S., & Hosomi, M. (2006). Nitrogen transformation in surface flow wetland planted Forage Rice receiving river water. In: Proceedings of 10th International Conference on Wetland Systems for Water Pollution Control, Lisbon, September, pp. 219–227.Google Scholar