The impact of temperature and gas-phase oxygen on kinetics of in situ ammonia removal in bioreactor landfill leachate.
Microcosm experiments aimed at defining a rate equation that describes how different environmental conditions (i.e., gas-phase oxygen concentrations, temperature and ammonia concentration) may impact in situ ammonia removal were conducted. Results indicate that ammonia removal can readily occur at various gas-phase oxygen levels (between 0.7% and 100%) and over a range of temperatures (22, 35 and 45 degrees C). Slowest rates occurred with lower gas-phase oxygen concentrations. All rate data, except at 45 degrees C and 5% oxygen, fit well (r2=0.75) to a multiplicative Monod equation with terms describing the impact of oxygen, pH, temperature and ammonia concentration. All ammonia half-saturation values are relatively high when compared to those generally found in wastewater treatment, suggesting that the rate may be affected by the mass transfer of oxygen and/or ammonia. Additionally, as the temperature increases, the ammonia half-saturation value also increases. The multiplicative Monod model developed can be used to aid in designing and operating field-scale studies.
Berge
Nicole D
ND
Civil and Environmental Engineering Department, Tufts University, 200 College Ave., 113 Anderson Hall, Medford, MA 02155, USA. nicole.berge@tufts.edu
Reinhart
Debra R
DR
Dietz
John D
JD
Townsend
Tim
T
D000641:Ammonia / Q000302:isolation & purification*; D019149:Bioreactors; D005740:Gases / Q000737:chemistry*; D007700:Kinetics; D010100:Oxygen / Q000737:chemistry*; D012037:Refuse Disposal; D013696:Temperature; D014874:Water Pollutants, Chemical / Q000737:chemistry* / Q000302:isolation & purification
D005740:Gases; D014874:Water Pollutants, Chemical; D000641:Ammonia; D010100:Oxygen