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Comparison of Simultaneous Nitrification and Denitrification for Three Different Reactors.

Khanitchaidecha W, Nakaruk A, Koshy P, Futaba K - Biomed Res Int (2015)

Bottom Line: Discharge of high NH4-N containing wastewater into water bodies has become a critical and serious issue due to its negative impact on water and environmental quality.Under intermittent aeration, nitrification and denitrification occurred simultaneously in the aerobic and anaerobic periods.Moreover, internal carbon was consumed efficiently for denitrification.

View Article: PubMed Central - PubMed

Affiliation: Department of Civil Engineering, Faculty of Engineering, Naresuan University, Thailand ; Centre of Excellence for Innovation and Technology for Water Treatment, Naresuan University, Thailand.

ABSTRACT
Discharge of high NH4-N containing wastewater into water bodies has become a critical and serious issue due to its negative impact on water and environmental quality. In this research, the performance of three different reactors was assessed and compared with regard to the removal of NH4-N from wastewater. The highest nitrogen removal efficiency of 98.3% was found when the entrapped sludge reactor (ESR), in which the sludge was entrapped in polyethylene glycol polymer, was used. Under intermittent aeration, nitrification and denitrification occurred simultaneously in the aerobic and anaerobic periods. Moreover, internal carbon was consumed efficiently for denitrification. On the other hand, internal carbon consumption was not found to occur in the suspended sludge reactor (SSR) and the mixed sludge reactor (MSR) and this resulted in nitrogen removal efficiencies of SSR and MSR being 64.7 and 45.1%, respectively. Nitrification and denitrification were the main nitrogen removal processes in the aerobic and anaerobic periods, respectively. However, due to the absence of sufficient organic carbon, denitrification was uncompleted resulting in high NO3-N contents in the effluent.

No MeSH data available.


Related in: MedlinePlus

(a) Nitrogen removal efficiency and (b) nitrogen profile of ESR.
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Related In: Results  -  Collection


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fig3: (a) Nitrogen removal efficiency and (b) nitrogen profile of ESR.

Mentions: The ESR was operated under intermittent aeration for two hours; the DO was ~4-5 mg/L in aerobic condition and this value dropped to ~0.5 mg/L in anaerobic condition. During 25 days of operation, the variations in the nitrogen removal efficiency and nitrogen concentrations are presented in Figure 3(a). The nitrogen removal efficiency was relatively stable at 98.3%, even though a low C/N ratio of 1.5 was maintained as was the case in the SSR. In the aerobic 1 stage in Figure 3(b), the 24 mg/L of NH4-N was oxidised while only 13 mg/L of NO2-N and NO3-N was detected. These results suggest that nitrification and denitrification occurred simultaneously in aerobic condition which had bulk DO value of ~4-5 mg/L. Due to the mass transfer (of oxygen, NH4-N, and NO3-N) inside the sludge pellet, it induced the aerobic zone for nitrification at the pellet surface and the anaerobic zone for denitrification at the pellet core. Moreover, the use of entrapped sludge can provide advantages of higher mechanical strength and chemical resistance [19].


Comparison of Simultaneous Nitrification and Denitrification for Three Different Reactors.

Khanitchaidecha W, Nakaruk A, Koshy P, Futaba K - Biomed Res Int (2015)

(a) Nitrogen removal efficiency and (b) nitrogen profile of ESR.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4562362&req=5

fig3: (a) Nitrogen removal efficiency and (b) nitrogen profile of ESR.
Mentions: The ESR was operated under intermittent aeration for two hours; the DO was ~4-5 mg/L in aerobic condition and this value dropped to ~0.5 mg/L in anaerobic condition. During 25 days of operation, the variations in the nitrogen removal efficiency and nitrogen concentrations are presented in Figure 3(a). The nitrogen removal efficiency was relatively stable at 98.3%, even though a low C/N ratio of 1.5 was maintained as was the case in the SSR. In the aerobic 1 stage in Figure 3(b), the 24 mg/L of NH4-N was oxidised while only 13 mg/L of NO2-N and NO3-N was detected. These results suggest that nitrification and denitrification occurred simultaneously in aerobic condition which had bulk DO value of ~4-5 mg/L. Due to the mass transfer (of oxygen, NH4-N, and NO3-N) inside the sludge pellet, it induced the aerobic zone for nitrification at the pellet surface and the anaerobic zone for denitrification at the pellet core. Moreover, the use of entrapped sludge can provide advantages of higher mechanical strength and chemical resistance [19].

Bottom Line: Discharge of high NH4-N containing wastewater into water bodies has become a critical and serious issue due to its negative impact on water and environmental quality.Under intermittent aeration, nitrification and denitrification occurred simultaneously in the aerobic and anaerobic periods.Moreover, internal carbon was consumed efficiently for denitrification.

View Article: PubMed Central - PubMed

Affiliation: Department of Civil Engineering, Faculty of Engineering, Naresuan University, Thailand ; Centre of Excellence for Innovation and Technology for Water Treatment, Naresuan University, Thailand.

ABSTRACT
Discharge of high NH4-N containing wastewater into water bodies has become a critical and serious issue due to its negative impact on water and environmental quality. In this research, the performance of three different reactors was assessed and compared with regard to the removal of NH4-N from wastewater. The highest nitrogen removal efficiency of 98.3% was found when the entrapped sludge reactor (ESR), in which the sludge was entrapped in polyethylene glycol polymer, was used. Under intermittent aeration, nitrification and denitrification occurred simultaneously in the aerobic and anaerobic periods. Moreover, internal carbon was consumed efficiently for denitrification. On the other hand, internal carbon consumption was not found to occur in the suspended sludge reactor (SSR) and the mixed sludge reactor (MSR) and this resulted in nitrogen removal efficiencies of SSR and MSR being 64.7 and 45.1%, respectively. Nitrification and denitrification were the main nitrogen removal processes in the aerobic and anaerobic periods, respectively. However, due to the absence of sufficient organic carbon, denitrification was uncompleted resulting in high NO3-N contents in the effluent.

No MeSH data available.


Related in: MedlinePlus