Nutrient Overload The Pollution of Nitrogen &...

Underwood Engineers 9/14/2011

1:15 PM GSRWA Field Day 1

Nutrient Overload The Pollution of Nitrogen &

Phosphorus

6th Annual Operator Field Day

Granite State Rural Water AssociationSeptember 13, 2011

Kitty Lane, Eastern Analytical

Steve Clifton, Underwood Engineers

TODAY’S AGENDA

Sampling Plan

Examples

BNR Overview

Lebanon WWTF



Sampling Plan

What to Sample

• For Permit Compliance

• For Process Performance

• For Modeling Parameters

Typical Testing Requirements for NPDES Permit

Influent TestingTSSVSSpHTemperatureBOD5COD – total and solubleTP - Soluble and ParticulateTotal Nitrogen – TKN and AmmoniaNitrate/Nitrite maybe

Effluent TestingTSSpHBOD5COD – total and solubleTP – soluble and particulateTotal Nitrogen

TKNParticulate Organic NDissolved Organic NAmmonia

Nitrates and Nitrites



Typical Testing for Process

• Aerobic Stages– Nitrification, BOD5 removal

• Anoxic Stages– Denitrification

• Anaerobic Stages– Phosphorus release

• Sidestreams– Sometimes a major load to the process!

Typical Testing for Modeling Parameters

BioWin Sampling Requirements

(2) Primary Effluent Sample Chain

Primary Effluent Sample

Homogenize

COD BOD TKN TP

Filter (GF 1.2 um)

TSS VSS

COD NH3 PO4

Flocculate and filter (GF 1.2 um)

COD

Filtrate Filtrate

PO4 on Filtrate

0.45 um membrane

9



COD Fraction

Total Influent COD

Biodegradable

Readily Biodegradable

Soluble

Complex

SCFA (VFA)

Slowly Biodegradable Particulate

Colloidal

Particulate

Unbiodegradable

Soluble

Particulate

Wastewater Characteristics Concentration (mg/L) Fractions

Typical COD

Total COD 250 – 700

Readily Biodegradable COD 25 – 125 0.05 – 0.25

Slowly Biodegradable COD 200 - 400 0.4 - 0.80

Soluble Unbiodegradable COD 20 – 50 0.04 – 0.16

Particulate Unbiodegradable COD 35 – 110 0.07 – 0.22

CHEMICAL OXYGEN DEMAND

TKN Fraction

Total Influent TKN

Ammonia – N

(free and saline)

Total Organic Nitrogen

Biodegradable

Soluble

Particulate

Unbiodegradable

Soluble

Particulate




Typical Nitrogenous Material

TKN 25 – 70

Free and Saline Ammonia 20 – 30 0.5 – 0.75

Biodegradable organically bound TKN

0 – 10 0 – 0.25

Soluble unbiodegradable TKN

0 – 5 0 – 0.07

Particulate unbiodegradableTKN

2 - 8 0.03 – 0.07

NITROGEN FRACTIONS

TP Fraction

Total Influent Phosphorus

Orthophosphate

Organically Bound Phosphorus

Biodegradable

Soluble

Particulate

Unbiodegradable

Soluble

Particulate


Typical Phosphorus Material

Total Phosphorus – TP 4 – 15

Orthophosphate 2 – 12 0.50 – 0.85

Biodegradable organically bound TP

0 – 10 0 – 0.25

Soluble unbiodegradable TP 0 - ? 0 - ?

Particulate unbiodegradable TP 1 - 4 0.02 – 0.03

PHOSPHORUS FRACTIONS



TSS Fraction

Total Influent Suspended Solids

Volatile Solids

nbVSS

bVSS

Inert Solids

9/14/2011 Updated BNR Schematics.pptx

Wastewater Characteristics Concentration (mg/L)

Fractions

Typical Influent TSS

Raw Total Suspended Solids - TSS 150 - 300

Raw Volatile Suspended Solids – VSS 125 – 255 0.7 – 0.85

Inorganic Suspended Solids - ISS 25 – 45 0.15 – 0.3

TSS FRACTIONS

Examples



Wastewater CharacterizationExamples

Newmarket, NH

Lebanon, NH

Merrimack, NH

Newmarket, NH

• Design Flow = 0.85 MGD

• Currently at 0.6 MGD

• Domestic flows

• Trickling filters

• Anaerobic Digesters



Lebanon, NH

• Design Flow = 3.18 MGD

• Currently at 2.0 MGD

• Domestic, commercial, and industrial flows

• DAF and centrifuge

• Septage

Merrimack, NH

• Design Flow = 4.14MGD

• ADF = 2.0 MGD

• Municipal and Anheuser-Busch flows

• Going towards A2/O



Wastewater Characteristics Newmarket, NHmg/L

Lebanon, NHmg/L

Merrimack, NH

mg/L

Organic Material - COD

Total COD 481 443 771

COD glass filtered 156 203 267

COD membrane filtered 90 165 171

COD floc/filtered 91 111 156

CHEMICAL OXYGEN DEMAND

Wastewater Characteristics

Newmarket, NHmg/L

Lebanon, NHmg/L

Merrimack, NH

mg/L

Nitrogenous Material

TKN 42 35 53

TKN glass filtered 31 29 25

NH3-N 27 24 24

NOx 0.6 0.7 10

NITROGEN FRACTIONS



Wastewater Characteristics

Newmarket, NHmg/L

Lebanon, NHmg/L

Merrimack,NH

mg/L

Phosphorus Material

Total Phosphorus – TP 5.7 5.7 13

Orthophosphate 3.2 2.6 6.2

PHOSPHORUS FRACTIONS

Fractions

Ratios Newmarket Lebanon Merrimack

COD:BOD 2.21 3.47 2.38

VSS:TSS 0.86 0.81 0.56

NH3:TKN 0.64 0.64 0.45

BOD:TKN 5.4 4.0 4.1

COD:TP 91 75 41

BOD:TP 42 23 17.3

PO4:P 0.59 0.42 0.49

Rules of Thumb• COD/TP = 40:1

• BOD/TP = 20:1

• COD/TKN = 4:1

Nitrification consumes• 4.6 lb O2 / lb NH3-N oxidized

• 7.1 lb alkalinity / lb NH3-N oxidized

Denitrification recovers

• 3.6 lb alkalinity / lb NO3 - N denitrified

• 2.9 lb O2 / lb NO3 - N denitrified



ORP – Oxidation Reduction Potential

Activity Range, mv e- AcceptorCBOD oxidation +50 to +200 O2

PolyP development +40 to +250 O2

Nitrification +150 to +350 O2

Denitrification -50 to +50 NO3-

PolyP breakdown -40 to -175 NO3-, SO4

=

Sulfide formation -50 to -250 SO4=

Acid formation -40 to -200 Organics

Methane formation -200 to -350 Organics

(Goronzy, et.al. 1992)

BNR Overview

BNR – Biological Nutrient Removal

Three major methods of pollutant removal

Biological –Fixed Film or Suspended Growth

Chemical – Adding chemicals

Physical – Settling, filtration, screening



ACTIVATED SLUDGE

RETURN SLUDGE

AERATED

ACTIVATED SLUDGE (Aerobic Stage)

SECONDARY CLARIFIER

INFLUENT

Today Biological Nutrient Removal

• Aerobic Stage– BOD5 Removal

– Nitrification

• Anaerobic and Anoxic Stages– Phosphorous Removal

– Nitrogen Removal

– Combined Phosphorus and Nitrogen Removal

Anaerobic Stage

• Anaerobic stages are unaerated zones within the activated sludge process that will favor Phosphate Accumulating Organisms when no DO is present and no nitrates are present

• Phosphorus is released in an anaerobic zone and taken up in greater quantities in the aerobic stage



Anaerobic Stage• Conditions critical to phosphorus release in the

anaerobic stage?– Readily biodegradable COD– No dissolved oxygen– No Nitrates– BOD5 to TP ratio > 20 for low TP effluent

• Benefits of an anaerobic stage?- Uptake of BOD5 going to Aerobic Stage- Reduction in sludge to dispose- Well settling sludge

• Phoredox Process (AO Process) for Phosphorus Removal

TWO STAGE ACTIVATED SLUDGE

ANAEROBIC STAGE AEROBIC STAGE

RETURN SLUDGE

SECONDARYCLARIFIER

INFLUENT

Anoxic Stage

• Started out with “Selectors” that favored non-filamentous bacteria

• Selectors morphed into anaerobic and anoxic stages within the activated sludge process

• Anoxic stages are unaerated zones within the activated sludge process, that when no DO is present and nitrates are present, will favor denitrification bacteria growth



• Modified Ludzak-Ettinger Process for Nitrogen Removal

TWO STAGE ACTIVATED SLUDGE

ANOXIC STAGE AEROBIC STAGE

NITRATE RECYCLE

RETURN SLUDGE

SECONDARYCLARIFIER

INFLUENT

Various BNR Process

• A2O• UCT• VIP• MUCT• 4 and 5 STAGE BARDENPHO• SBR• IFAS• BIOMAG

A2O ProcessLEBANON, NH THREE STAGE ACTIVATED SLUDGE PROCESS

(MLE and A2/O PROCESS)



AEROBICANOXICANAEROBIC

RETURN SLUDGE

NITRATE RECYCLE

MLE / A2O Process

SECONDARYCLARIFIER

MUCT Somersworth, NH

77,000 gal 77,000 gal 39,000 gal 98,000 gal 619,000 gal

AEROBIC(2) ANOXIC(2) ANAEROBIC

RETURN SLUDGE

NITRATE RECYCLEMLSS RETURN

2 4 51 3

MUCT (2 Trains) Somersworth, NH

2.4 MGD Design Flow



Pease SBRs

Pease WWTF

-5

0

5

10

15

20

25

30

Effluent TN, mg/L

TN <5

No Biopharmaceutical Discharge

Hooksett, NH IFASGraves Engineering

SECONDARY

CLARIFIER

ANOXIC

RETURN SLUDGE

NITRATE RECYCLE

AEROBICANAEROBIC



Hooksett IFAS

Plastic media

Hooksett On Line



NORTH CONWAY WWTF5 STAGE BARDENPHO PROCESS

AN

AX

AER

AER

AX

Allenstown, NH BioMag (HTA)

SECONDARY

CLARIFIER

ANOXIC

RETURN SLUDGE

NITRATE RECYCLE

AEROBICANAEROBIC

Mix Tank

Drum KadyMill

Screen

Mag Feeder

Waste Sludge Storage

Mag Recovery



THE END

THANK YOU FOR ATTENDING

THESE SLIDES CAN BE FOUND ON OUR WEBSITE AT

UNDERWOODENGINEERS.COM

Chemical Phosphorus RemovalAlum, PAC, ACH

• Al 3+ + PO43- AlPO4

Ferric Chloride

• FeCl3 + PO43- FePO4 + Cl-

Dosages can be as high as 7:1 on a weight ratio

Ratio Mole Ratio Weight Ratio Optimum pH

Al:P 1:1 0.87:1 5.5 – 6.5

Fe+3:P 1:1 1.8:1 4.5 - 5

Nutrient Overload The Pollution of Nitrogen &...

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