A kinetic study of autohydrogenotrophic denitrification at the optimum pH and sodium bicarbonate dose.
In this study the kinetics of autohydrogenotrophic denitrification was studied under optimum solution pH and bicarbonate concentration. The optimal pH and bicarbonate concentration were firstly obtained using a design of experiment (DOE) methodology. For this purpose a total of 11 experiments were carried out. Sodium bicarbonate concentrations ranging of 20-2000 mg/L and pH values from 6.5 to 8.5 were used in the optimization runs. It was found that the pH has a more pronounced effect on the denitrification process as compared to the bicarbonate dose. The developed quadratic model predicted the optimum conditions at pH 8 and 1100 mg NaHCO(3)/L. Using these optimal conditions, the kinetics of denitrification for nitrate and nitrite degradation were investigated in separate experiments. Both processes were found to follow a zero order kinetic model. The ultimate specific degradation rates for nitrate and nitrite remediation were 29.60 mg NO(3)(-)-N/g MLVSS/L and 34.85 mg NO(3)(-)-N/g MLVSS/L respectively, when hydrogen was supplied every 0.5h.
Ghafari
Shahin
S
Faculty of Engineering, Department of Civil Engineering, University of Malaya, Kuala Lumpur, Malaysia.
Hasan
Masitah
M
Aroua
Mohamed Kheireddine
MK
D000704:Analysis of Variance; D052818:Autotrophic Processes / Q000187:drug effects*; D001673:Biodegradation, Environmental / Q000187:drug effects; D006859:Hydrogen / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D007700:Kinetics; D008954:Models, Biological; D009566:Nitrates / Q000378:metabolism; D009573:Nitrites / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism*; D010084:Oxidation-Reduction / Q000187:drug effects; D010100:Oxygen / Q000302:isolation & purification; D017693:Sodium Bicarbonate / Q000494:pharmacology*; D013997:Time Factors
D009566:Nitrates; D009573:Nitrites; D006859:Hydrogen; D017693:Sodium Bicarbonate; D009584:Nitrogen; D010100:Oxygen