Simultaneous Nitrification and Denitrification in a Sequencing Batch Reactor Will Lambert Robert Nwaokoro Stephen Russo

Simultaneous Nitrification Simultaneous Nitrification and Denitrification in a and Denitrification in a Sequencing Batch ReactorSequencing Batch Reactor

Will LambertWill Lambert

Robert NwaokoroRobert Nwaokoro

Stephen RussoStephen Russo

SND in SBRSND in SBR

Nitrification/Denitrification Nitrification/Denitrification BasicsBasics

Introduction to SND Experimental Methods Results Conclusions Suggestions/Questions?


Why remove nitrogen?Why remove nitrogen? Limiting nutrient in oceans and estuaries.

Nitrates in drinking water cause Methemoglobinemia

“blue-baby” syndrome.


Denitrification (anaerobic)

Nitrification (aerobic)Nitrosobacters Denitrification (anaerobic)

Nitrification (aerobic)Nitrosomonas

Ammonification

Assimilation

Ammonia

Nitrite

N2 (gas)

Organic Nitrogen

Nitrate

Fixation

Nitrogen Cycle in Waste Treatment


Nitrification/Denitrification Basics

Introduction to SNDIntroduction to SND Experimental Methods Results Conclusions Suggestions/Questions?

Introduction to SNDIntroduction to SND

What is SND?What is SND? Simultaneous reactions occur of:Simultaneous reactions occur of:

AmmonificationAmmonification NitrificationNitrification DenitrificationDenitrification

Normally occur in different stepsNormally occur in different steps Why use SND? Obstacles to SND Solutions


What is SND?

Why use SND?Why use SND? Reduction of:Reduction of:

CostCost EnergyEnergy SludgeSludge

Obstacles to SND Solutions


What is SND? Why use SND?

Obstacles to SNDObstacles to SND Nitrification is aerobicNitrification is aerobic Denitrification is anaerobicDenitrification is anaerobic

Solutions


What is SND? Why use SND? Obstacles to SND

SolutionsSolutions Achieve aerobic/anaerobic Achieve aerobic/anaerobic

environment:environment: Low DOLow DO

0.5 – 1 mg/L0.5 – 1 mg/L Large flocsLarge flocs BiofilmsBiofilms


Nitrification/Denitrification Basics Introduction to SND

Experimental MethodsExperimental Methods StatesStates Testing MethodsTesting Methods

Results Conclusions Suggestions/Questions?

Experimental Methods: Experimental Methods: StatesStates

Fill with WasteFill with Waste Run for 18.3 sRun for 18.3 s 140 mL delivered140 mL delivered

Based on 459 mL/min peristaltic pump flow Based on 459 mL/min peristaltic pump flow raterate

Fill with Water Aerate Settle Drain


Fill with Waste

Fill with WaterFill with Water Run for 350 s AND…Run for 350 s AND… Reactor volume is 4 L over 5 s averageReactor volume is 4 L over 5 s average

Fail safe if pump failed to deliver Fail safe if pump failed to deliver appropriate amount of fluidappropriate amount of fluid

Aerate Settle Drain


Fill with Waste Fill with Water

AerateAerate Run time variedRun time varied

8, 18, 24 hours8, 18, 24 hours Aeration rate controlled by PID controlAeration rate controlled by PID control

Target DO = 0.5 mg/LTarget DO = 0.5 mg/L Settle Drain

Experimental Methods: Experimental Methods: States: AerateStates: Aerate

Proportional, Integral, and Derivative (PID) Proportional, Integral, and Derivative (PID) ControlControl Equation: Equation:

Trial and error determined Trial and error determined PP, , II, and , and DD values values Effective control was met when DO reached 0.5 mg/LEffective control was met when DO reached 0.5 mg/L

D

D

I

I

P

c tTt

TKtu

1)(


Fill with Waste Fill with Water Aerate

SettleSettle Run for 1 hourRun for 1 hour

More than enough time for settlingMore than enough time for settling Left unchangedLeft unchanged

Drain


Fill with Waste Fill with Water Aerate Settle

DrainDrain Run until 1.2 L remained in reactorRun until 1.2 L remained in reactor


Nitrification/Denitrification Basics Introduction to SND

Experimental MethodsExperimental Methods StatesStates

Testing MethodsTesting Methods Results Conclusions Suggestions/Questions?

Experimental Methods: Testing Experimental Methods: Testing MethodsMethods

Micro-Phenate MethodMicro-Phenate Method Determine ammonia concentration as Determine ammonia concentration as

ammonia/nitrogenammonia/nitrogen Standards consist of:Standards consist of:

Phenol SolutionPhenol Solution Sodium nitroprussideSodium nitroprusside Alkaline citrateAlkaline citrate Sodium hypochloriteSodium hypochlorite Oxidizing SolutionOxidizing Solution

Standards: 0, 0.2, 0.4, 0.6 mg N-NHStandards: 0, 0.2, 0.4, 0.6 mg N-NH44/L /L Spectrophotometer analysis at 640 nmSpectrophotometer analysis at 640 nm

Nitrate-nitrogen standards Sampling

Experimental Methods: Experimental Methods: Testing MethodsTesting Methods

Micro-Phenate Method

Nitrate-nitrogen standardsNitrate-nitrogen standards Cadmium gravimetric methodCadmium gravimetric method

Hach Corporation: Nitriver ® and Nitraver Hach Corporation: Nitriver ® and Nitraver ® reagent packets® reagent packets

Standards: 0, 2, 6, 10 mg N-NOStandards: 0, 2, 6, 10 mg N-NO33/L/L Spectrophotometer analysis at 542nmSpectrophotometer analysis at 542nm

Sampling

Experimental Methods: Experimental Methods: Testing MethodsTesting Methods

Micro-Phenate Method Nitrate-nitrogen standards

SamplingSampling End of aeration stateEnd of aeration state Filtered through Millipore filter Filtered through Millipore filter RefrigeratedRefrigerated Ammonia samplesAmmonia samples

Diluted by 10xDiluted by 10x


Nitrification/Denitrification Basics Introduction to SND Experimental Methods

ResultsResults Conclusions Suggestions/Questions?

Results: PIDResults: 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

(m

g/L

)

DO (mg/L)

Average DO = 0.505 mg/LStandard Deviation = 0.015

Results: Ammonia StandardsResults: Ammonia Standards

-0.1

-0.05

0

0.05

0.1

0.15

0.2

0.25

0.3

0 200 400 600 800 1000

Wavength (λ)

Ab

sorb

ance

0 mg/L

0.2 mg/L

0.4 mg/L

0.6 mg/L

y = 0.436x - 0.0158

R2 = 0.9737

-0.05

0

0.05

0.1

0.15

0.2

0.25

0.3

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7

Concentration (mg N-NH3/L)

Abso

rban

ce a

t 640

λ

Results: Nitrate StandardsResults: Nitrate Standards

-0.5

0

0.5

1

1.5

2

2.5

0 200 400 600 800 1000

Wavelength (λ)

Abso

rban

ce 0 mg/L

2 mg/L

6 mg/L

10 mg/L

y = 0.1611x - 0.0451

R2 = 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)

Ab

sorb

ance

at

542

λ

Results: SamplesResults: Samples

Aeration Time Aeration Time (hr)(hr)

Absorbance Absorbance (542 nm(542 nm))

Concentration Concentration (mg N-NO(mg N-NO33/L)/L)

2424 0.630.63 4.214.21

1818 0.540.54 3.643.64

88 1.841.84 11.7211.72

Nitrate Concentrations

Aeration TimeAeration Time

(hr)(hr)Absorbance Absorbance

(640 nm)(640 nm)Diluted Diluted

Concentration Concentration (mg (mg

N-NHN-NH33/L)/L)

Actual Actual Concentration Concentration (mg (mg

N-NHN-NH33/L)/L)

2424 1.361.36 3.163.16 31.5731.57

1818 1.221.22 2.832.83 28.3428.34

88 1.051.05 2.442.44 24.4324.43

Ammonia Concentrations

Results: Total Nitrogen Results: Total Nitrogen RemovalRemoval

Aeration Aeration Cycle (hr)Cycle (hr)

Total N Total N Remaining Remaining

(mg/L)(mg/L)

N Removal N Removal (mg/L)(mg/L)

% Removal% Removal

2424 32.3332.33 8.578.57 20.9620.96

1818 35.1935.19 5.715.71 13.9613.96

88 36.1536.15 4.754.75 11.6111.61


Nitrification/Denitrification Basics Introduction to SND Experimental Methods Results

ConclusionsConclusions Suggestions/Questions?

ConclusionsConclusions

Total nitrogen removal efficiencies appeared Total nitrogen removal efficiencies appeared to make senseto make sense Broken down to nitrate and ammonia, unclear Broken down to nitrate and ammonia, unclear

datadata One long aeration cycle should have been One long aeration cycle should have been

runrun Sampled periodically during that cycleSampled periodically during that cycle

SND is possible at laboratory scale,SND is possible at laboratory scale, Easier at full scaleEasier at full scale

Achieve a more heterogeneous environmentAchieve a more heterogeneous environment


Nitrification/Denitrification Basics Introduction to SND Experimental Methods Results Conclusions

Suggestions/Questions?Suggestions/Questions?

SuggestionsSuggestions

Questions?Questions?&&

Documents

Simultaneous Nitrification and Denitrification in a Sequencing Batch Reactor Will Lambert Robert Nwaokoro Stephen Russo