simultaneous nitrification denitrification

8/3/2019 Simultaneous Nitrification Denitrification

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Simultaneous Nitrification

and Den i t r i f i ca t ion in aSequencing Batch Reactor

Will Lambert

Robert NwaokoroStephen Russo


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SND in SBR

Nitrification/Denitrification Basics Introduction to SND

Experimental Methods

Results

Conclusions

Suggestions/Questions?


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Nitrification/Denitrification Basics

Why remove nitrogen? Limiting nutrient in oceans and estuaries.

Nitrates in drinking water causeMethemoglobinemiablue-baby syndrome.


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Denitrification (anaerobic)

Nitrification (aerobic)Nitrosobacters Denitrification (anaerobic)

Nitrification (aerobic)

Nitrosomonas

Ammonification

Assimilation

Ammonia

Nitrite

N2 (gas)

OrganicNitrogen

Nitrate

Fixation

Nitrogen Cycle in Waste Treatment


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SND in SBR


Introduction to SND Experimental Methods

Results

Conclusions



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Introduction to SND

What is SND?

Simultaneous reactions occur of:

Ammonification

Nitrification

Denitrification

Normally occur in different steps Why use SND?

Obstacles to SND

Solutions


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Introduction to SND

What is SND?

Why use SND?

Reduction of: Cost

Energy

Sludge

Obstacles to SND

Solutions


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Introduction to SND

What is SND?

Why use SND?

Obstacles to SND Nitrification is aerobic

Denitrification is anaerobic Solutions


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Introduction to SND

What is SND?

Why use SND?

Obstacles to SND

Solutions

Achieve aerobic/anaerobic environment:

Low DO

0.5 1 mg/L

Large flocs

Biofilms


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SND in SBR


Introduction to SND

Experimental Methods States

Testing Methods Results

Conclusions



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Experimental Methods: States

Fill with Waste

Run for 18.3 s

140 mL delivered Based on 459 mL/min peristaltic pump flow rate

Fill with Water

Aerate

Settle

Drain


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Fill with Waste

Fill with Water

Run for 350 s AND Reactor volume is 4 L over 5 s average

Fail safe if pump failed to deliver appropriateamount of fluid

Aerate

Settle

Drain


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Fill with Waste

Fill with Water

Aerate Run time varied

8, 18, 24 hours

Aeration rate controlled by PID control

Target DO = 0.5 mg/L

Settle

Drain


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Experimental Methods: States:

Aerate Proportional, Integral, and Derivative (PID) Control

Equation:

Trial and error determined P, I, and Dvalues Effective control was met when DO reached 0.5 mg/L

D

D

I

I

P

c

tTt

TKtu

1)(


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Fill with Waste

Fill with Water

Aerate

Settle

Run for 1 hour

More than enough time for settling

Left unchanged Drain


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Fill with Waste

Fill with Water

Aerate

Settle

Drain

Run until 1.2 L remained in reactor


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SND in SBR


Introduction to SND

Experimental Methods States

Testing Methods

Results Conclusions



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Experimental Methods: TestingMethods

Micro-Phenate Method Determine ammonia concentration as

ammonia/nitrogen Standards consist of:

Phenol Solution Sodium nitroprussideAlkaline citrate Sodium hypochlorite

Oxidizing Solution Standards: 0, 0.2, 0.4, 0.6 mg N-NH4/L Spectrophotometer analysis at 640 nm

Nitrate-nitrogen standards Sampling


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Experimental Methods: TestingMethods

Micro-Phenate Method

Nitrate-nitrogen standards

Cadmium gravimetric method

Hach Corporation: Nitriver and Nitraver reagent packets

Standards: 0, 2, 6, 10 mg N-NO3/L

Spectrophotometer analysis at 542nm Sampling


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Experimental Methods: Testing

Methods Micro-Phenate Method

Nitrate-nitrogen standards

Sampling End of aeration state

Filtered through Millipore filter

Refrigerated

Ammonia samples

Diluted by 10x


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Results: PID

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

4:42:54 PM 5:54:54 PM 7:06:54 PM 8:18:54 PM 9:30:54 PM

Time

DO(mg/L)

DO (mg/L)

Average DO = 0.505 mg/LStandard Deviation = 0.015


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Results: Nitrate Standards

-0.5

0

0.5

1

1.5

2

2.5

0 200 400 600 800 1000

Wavelength ()

Absorba

nce 0 mg/L

2 mg/L

6 mg/L

10 mg/L

y = 0.1611x - 0.0451R2 = 0.9954

-0.2

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

0 2 4 6 8 10 12

Concentration (mg N-NO3/L)

Absorbanceat542


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Results: Samples

Aeration Time(hr)

Absorbance(542 nm)

Concentration(mg N-NO3/L)

24 0.63 4.21

18 0.54 3.64

8 1.84 11.72

Nitrate Concentrations

Aeration Time

(hr)

Absorbance

(640 nm)

Diluted

Concentration(mg N-NH3/L)

Actual

Concentration(mg N-NH3/L)

24 1.36 3.16 31.57

18 1.22 2.83 28.34

8 1.05 2.44 24.43

Ammonia Concentrations


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Results: Total Nitrogen Removal

Aeration Cycle(hr)

Total NRemaining

(mg/L)

N Removal(mg/L)

% Removal

24 32.33 8.57 20.96

18 35.19 5.71 13.96

8 36.15 4.75 11.61


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SND in SBR


Introduction to SND

Experimental Methods Results

Conclusions Suggestions/Questions?


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Conclusions

Total nitrogen removal efficiencies appeared tomake sense

Broken down to nitrate and ammonia, unclear data One long aeration cycle should have been run

Sampled periodically during that cycle

SND is possible at laboratory scale,

Easier at full scale

Achieve a more heterogeneous environment


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Suggestions

Questions?

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simultaneous nitrification denitrification

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