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NUTRIENTS AND NUTRIENT ANALYSIS IN

WASTEWATER TREATMENT

BNR Lab Testing Parameters

Nitrogen

TNT 826 Total NEffluent Monitoring 826

TNT 880 Simplified TKN 880.pdfEffluent Monitoring

Customer approval required per region

DRB200

BNR LAB TESTING PARAMETERS

NitrogenTNT831 Ammonia 831.pdf

Influent, Effluent, and Process verificationTNT835 Nitrate 835

Effluent limits, anoxic and aerobic zones

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LAB TESTING FOR PHOSPHORUS

TNT843 for both Total P and OrthophosphateAnoxic , Aerobic, Effluent, and Process verificationLR 0.05─1.50 mg/L PO₄─P

0.15─4.50 mg/L PO₄ 843

TNT 843 can be used for ULR P

USEPA PhosVer3 PP method 8048 for the determination of Orthophosphate

VOLATILE FATTY ACIDS

For maximum Phosphorus release in an anaerobic zone an abundant supply of VFA should be available. 872

50─2500 mg/L as Acetic Acid

OUTLINE

(-3)

(-)

(-)

H

HH

N

N

O

O

O

N

OO

P

O O

O

O

• What are Nutrients?• Nitrogen• Phosphorous• Why Nutrients Matter• Nutrient Removal in Wastewater Treatment • Nutrient Analysis

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WHAT ARE NUTRIENTS?

• The term “nutrients” in the context of wastewater treatment describes a group of organic and inorganic nitrogen- and phosphorous-containing compounds

– Nitrogen• Inorganic - nitrate, nitrite, ammonia

• Organic - Urea, amino acids, proteins

– Phosphorous• Inorganic - orthophosphates, pyrophosphate, calcium phosphate

• Organic – nucleic acids, phospholipids, phosphoproteins, polyphosphates

NITROGEN• Present in fertilizers• Major contributor to nutrient pollution • Nitrogen gas (N2) makes up about 80% of our atmosphere• Can take on different forms in WW process

FORMS OF NITROGEN

• Main Forms of Nitrogen in a WWTP

N

OO

(-)

(-)

N

O

O

O

H

HH

N

NN

Ammonia (NH3)

Nitrite (NO2-)

Nitrate (NO3-)

Nitrogen gas (N2)

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PHOSPHOROUS• Present in fertilizers and detergents• Major contributor to nutrient pollution • Orthophosphate (PO4

-3) = Reactive Phosphorous • Can be present in different forms in WW process

FORMS OF PHOSPHOROUS• Polyphosphates/ Pyrophosphates • Orthophosphate ion (PO4

-3) • Orthophosphate may take the form of H2PO4

- and HPO4-2 ,

depending on pH• Can occur in different forms in WW process

Pyrophosphate

Adenosine Triphosphate

(ATP)

Phosphoric acidSodium Hexametaphosphate

WHY NUTRIENTS MATTER • Why nutrients matter

– Nutrients in wastewater effluent can accumulate at the outfall of a wastewater treatment facility and create conditions that are detrimental to both humans and the environment.

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WHY NUTRIENTS MATTER

• Environmental Effects– Eutrophication - A process where

increased nutrient levels promote excessive growth of algae and certain types of bacteria.

– Hypoxia – A result of eutrophication. When large colonies of algae die, and accumulate at the bottom of a river or lake, their subsequent decomposition and decay causes the aquatic environment to become oxygen-depleted. Hypoxia can be fatal to fish, crustaceans, and any other aquatic organisms that require oxygen to survive.

WHY NUTRIENTS MATTER• The USEPA has identified nutrient pollution

as a significant problem

• The National Pollutant Discharge Elimination System (NPDES) grants permits to wastewater treatment plants (WWTPs) that discharge their treated water back into the environment

• Any WWTPs that discharges to the environment have maximum nitrogen and/or phosphorous levels on their effluent permits

• If maximum levels are exceeded, the treatment facility can incur fines until the problem is corrected

WHY NUTRIENTS MATTER• In addition to the environmental impacts

that nutrients pose, wastewater plants are also interested in quantifying various nutrient levels to make their treatment processes more efficient, which can ultimately save them time and money

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SAMPLE NPDES PERMIT

WHERE ARE NUTRIENTS MEASURED?• Some measurement points in a WWTP

– Primary Clarifier – plant nutrient loading and overall removal

– Aeration Basin – A-basin nutrient loading and organics : nutrients ratio

– Nutrient Removal Basin Zones (aerobic, anoxic, anaerobic) – monitoring optimal nutrient removal conditions, and removal performance

– Secondary Clarifier – monitoring chemicalnutrient removal performance and chemical dosing

– Final Effluent – monitoring discharge permit compliance; overall nutrient removal performance

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NUTRIENT REMOVALPROCESS

MONITORING & CONTROL

• Nitrogen Removal –– Nitrification – Convert ammonia (NH3) to nitrate (NO3

-)

– Denitrification – Convert nitrate (NO3-) to nitrogen gas (N2)

• Phosphorous Removal (Biological) –– Phosphate release under anaerobic conditions

– Phosphate luxury uptake under aerobic conditions

– Phosphate removed by sludge wasting (WAS)

• Phosphorous Removal (Chemical) –– Dose chemical and settle out particulates containing phosphorous

NUTRIENT REMOVAL OVERVIEW

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NITROGEN REMOVAL

NITROGEN • Nitrogen Removal

– Nitrification - A 2-step process

• Bacteria (Nitrosomonas) convert ammonia to nitrite in the presence of oxygen

• Bacteria (Nitrobacter) convert nitrite to nitrate in the presence of oxygen

AMMONIA(NH3 )

NITRITE(NO2

-)→+ OXYGEN

(O2)

→+ OXYGEN

(O2)NITRITE

(NO2-)

NITRATE(NO3

-)

(Nitrosomonas)

(Nitrobacter)Step 2.

Step 1.

NITROGEN • Nitrogen Removal

– Denitrification – Under anoxic conditions nitrate is converted to nitrite, and ultimately to nitrogen gas.

NITRITE(NO2-)

NITROGEN GAS (N2 )

→NITRATE(NO3-)

→

NITRICOXIDE(NO)

NITROUSOXIDE(N2O)

→ →

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NITROGEN • Nitrification Monitoring and Control

BIOLOGICAL NITROGEN REMOVAL

O2 O2O2O2

Aerobic Zone

Anoxic Zone

NH3

Q (Flow)

Recycle to anoxic zone

O2

To 2o Clarifier

NITRIFICATIONDENITRIFICATION

N2 N2N2

|

|

|

NH3

NITROGEN • Nitrification – Controlling The Process

– Parameters

• Ammonia

• Nitrate

• DO

• ORP

• pH

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AMMONIA

•Where•Plant Influent

•Why•Monitor the ammonia loading before it gets to the nitrification basin (aeration basin).

•What

•AMTAXsc with Filter Probe sc• A-ISEsc, ANISEsc Ammonium probe

AMMONIA

AMTAX SC ANALYTICAL SECTION

(1) GSE: Gas Sensitive Electrode as detector

(2) Air pump to move liquids

(3) Dosing pump for reagent

(4) Electrolyte storage

(5) Cleaning solution

(6) 2 standard solutions

(7) Reagent

(8) Membrane storage

Range: 0.05 to 1000mg/L

1

2

5

4

6 6 7

3

8

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AMTAX SC GAS SENSITIVE ELECTRODE (GSE)

(1) Electrode

(2) Removable membrane cap

(3) Gas Sensitive Membrane

Filtrax Sample Filtration System

SAMPLE FILTRATION - BEST

Filtrax Sample Filtration System•Operating Principle

•The Filtrax prepares the sample through two ultra-filtration membranes (0.15 µ) that are immersed in the process tank

AMMONIA

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•Where•Nitrification Basin (Aeration Basin)

•Why•Monitor the efficiency of the nitrification system

•Control the amount of oxygen added (cost savings)

•What

•AMTAXsc with Filter Probe sc•A-ISEsc, ANISEsc Ammonium probe

AMMONIA

Real Time Nitrogen Control of Blowers.Lower Blower Costs

•Where•Plant Effluent

•Why•Monitor for upsets in the plant, or hidden processes

•Compliance with regulations

•What

•AMTAXsc

AMMONIA

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NITRATE

•Where•Between Denitrification and Nitrification basins

•Why•Control the amount of recirculated nitrates

•Optimize nitrogen removal system

•What

•NITRATAXsc UV Nitrate Analyzer

•N-ISEsc, ANISEsc

NITRATE

• Nitratax plus

• Nitratax eco

• Nitratax clear

• Self Cleaning

• Measurement Interval

– 1 to 30 minutes (user-selectable)

NITRATAX SC

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•The probe emits two wavelengths of ultraviolet light (210nm & 350nm)

•One photodetctor detects the absorbance of the 210nm light (mainly due to nitrates and nitrites)

•The other detector measures the absorbance of the 350nm light (organics, solids, and turbidity) flash

lamp

measuring gap

lmeß

lref

receiver

NITROGEN

NITRATAX PLUS SC

•Application Note

Nitratax Data

•Application Note

Nitratax Data

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•Where•Post Nitrification Basin (Aeration Basin)

•Why•Monitor the nitrification process

•Optimize nitrogen removal system

•What

•NITRATAXsc UV Nitrate Analyzer

•N-ISEsc, ANISEsc

NITRATE

•Where•Plant Effluent

•Why•Monitor for upsets in the plant, or hidden processes

•Compliance with regulations

•What

•NITRATAXsc UV Nitrate Analyzer

•N-ISEsc, ANISEsc

NITRATE

NITROGEN • Ammonia and Nitrate

– ANISE sc, N-ISE SC

• Ion selective electrode

• Automatic Chloride and Potassium compensation to eliminate interferences

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Sensor cartridge

(only wearing part)Sensor body

NITROGEN

• Ammonia and Nitrate

CARTRICAL Sensor Cartridge - One piece rugged

construction...

Nitrate ISE

Chloride electrode for

automatic compensation

from chloride interferences

pHD Reference for drift stable reference

...Factory calibrated -

A matrix correction is necessary only

Temperature Sensor for

temperature compensation

Ammonium ISE

Potassium electrode for

automatic compensation from

potassium interferences

NITROGEN

NITRIFICATION CONTROL PARAMETERS Parameter Laboratory Instrument Process Instrument

Ammonia • ISE + HQd• Colorimeter/Spectrophotometer

- DR6000- DR3900- DR900- PCII

• RTC-N, RTC-DN• Amtax sc• ANISE sc

Nitrate • ISE + HQd• Colorimeter/Spectrophotometer

- DR6000- DR3900- DR900- PCII

• ANISE sc• Nitratax sc

DissolvedOxygen

• LDO + HQd• Colorimeter/Spectrophotometer

- DR6000- DR3900- DR900- PCII

• LDO Model 2• Galvanic DO Sensor

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BENCHTOP PORTABLE DR6000 DR3900 DR900 Pocket

Colorimeter

• UV and white light source

• Over 250 pre-programmed methods

• 200 programmable custommethods

• White light source only• 240 pre-programmed

methods• 100 programmable

custom methods

• LED light source(4 fixed LEDs)

• 90 pre-programmed methods

• LED light source(1 fixed LED)

• Single parameter• 34 models

NITROGEN ANALYSIS

Nitrogen TestingTotal Nitrogen (TN)

Total Kjeldahl Nitrogen (TKN)

[Organic Nitrogen + Ammonia (inorganic )]

Nitrate (NO3-)

Nitrite (NO2-)

Inorganic Nitrogen

or[Total Nitrogen – (Nitrate + Nitrite)]

NITROGEN • Nitrification – Controlling The Process

– Other Parameters

• ORP

• pH

• Alkalinity

• TSS

• Organics

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PHOSPHOROUS REMOVAL

PHOSPHOROUS • Biological Phosphorous Removal

– Also a 2-step process

• Under anaerobic conditions, phosphate accumulating organisms (PAOs) consume organics (volatile fatty acids, VFAs) and release phosphate

• Under aerobic conditions, phosphate accumulating organisms take up all phosphate released during anaerobic phase, as well as any other phosphate in solution

ORGANIC(VFA )

→+

PAO

→+

PAO

OXYGEN(O2)

PHOSPHATELUXURY UPTAKE

Step 2.

Step 1.(NO OXYGEN)

PHOSPHATERELEASE

• Biological Phosphorous Removal – Aeration Basin – Under anaerobic conditions, phosphate-accumulating organisms

convert small organic compounds (volatile fatty acids) to other organic compounds that ultimately result in the release of phosphate from the organism

PHOSPHOROUS

Organics - VFA(e.g., C2H4O2)

Orthophosphate(PO4

-3)

Anaerobic Conditions

O2O2 O2

PAO

PAOPAO

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• Phosphorous Removal – Aeration Basin (biological)– Under aerobic conditions, phosphate-accumulating organisms

consume all the phosphate released in the anaerobic phase, as well as any other phosphate in solution (luxury uptake). Then phosphate-loaded bacteria are removed through the sludge wasting process, resulting in phosphorous removal

PHOSPHOROUS

phosphate (PO4-3)

from anaerobic stage

Aerobic Conditions

+ more phosphate

in solution

O2

O2

O2

O2

O2

O2

PAO

PAOPAO

O2

O2

BIOLOGICAL P REMOVAL

ANAEROBICNo DO, No Nitrate

AEROBICDO > 0.5mg/L

Poly-P

PHA

Glycogen

EMP

CO2

NADH

VFA

Ac-COA

Energy

PO4

PO4 PO4

Poly-P

PHA

Glycogen

CO2 + H2O

O2

PO4

PO4

You can’t control bacteriaYou can only control their environment

COMBINED BIOLOGICAL PHOSPHOROUS & NITROGEN REMOVAL

Aerobic Zone

Anoxic Zone

Anaerobic Zone

O2O2NO3

DENITRIFICATION

NITRIFICATION

Biological

Phosphorous

Removal

O2O2 O2

O2

3 ZonesPO4-3NH3

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PHOSPHOROUS

PHOSPHOROUS ANALYSIS

Phosphorous Testing

Total Phosphorous (TP)

Organic Phosphorous Inorganic Phosphorous

•Orthophosphate

• Calcium Phosphate

• Nucleic Acids• Phosphoproteins• ATP

** Effluent Permit Limits are in Total Phosphorous (TP)

•Where•Plant Influent

•Why•Monitor phosphorous load before it gets to phosphorous removal system

•What

•PHOSPHAXsc Phosphate Analyzer with Filter Probe sc

PHOSPHOROUS

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PHOSPHAX SC ANALYTICAL SECTION

(1) 2-beam-LED-photometer with colorimetric method (yellow), two ranges

(2) Air pump to move liquids

(3) Dosing pump for reagent

(4) Cleaning solution

(5) Reagent

Range: 0.05 to 50mg/L PO4-P

1

2

54

3

•Where•Phosphorous Removal System

•Why•Monitor or control chemical addition/efficiency of removal system

•Monitor Biological Phosphorus Removal system

•What

•PHOSPHAXsc Phosphate Analyzer with Filtration

PHOSPHOROUS

Real Time Phosphorus Chemical Feed Control.Optimize Chemical Dosing

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•Where•Plant Effluent

•Why•Monitor for upsets in the plant

•Compliance with regulations

•What

•PHOSPHAXsc Phosphate Analyzer with Filtration

PHOSPHOROUS

NUTRIENT REMOVAL PARAMETERS

• pH and Alkalinity- pH can be depressed by Nitrification.

7.14 lb. of alkalinity consumed per lb. of NH₃ oxidized.

• ORP/Oxidation Reduction Potential

Dissolved Oxygen is difficult to measure accurately in both an Anoxic and Anaerobic environment.

• And of Course the all important DO measurement in an Aerobic environment for Nitrification and Luxury uptake of Phosphorus or consider Ammonia based aeration

with RTC LDO2

BIOLOGICAL NUTRIENT REMOVAL BASICS

Anaerobic ZonePAO release huge amounts of P to access VFA.

Anoxic ZoneHeterotrophic Facultative Bacteria respirate using the oxygen attached to Nitrate.

Aerobic ZoneConversion of Ammonia through nitrification.Organisms take up to ten times their body weight in Phosphorus in a processcalled “Luxury Uptake”.

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BNR TREATMENT SCHEMES

DO between 2.0 and 4.0 mg/L or RTC with Ammonia based Aeration

Three Stage Phoredox A²/O

AnaerobicP release

Anoxicdenitrification

AerobicNitrification and Luxury uptakeDO 0.0 mg/l

ORP < -150 mvDO < .5 mg/LORP between -150 and + 150 mv

BNR TREATMENT SCHEMESUNIVERSITY OF CAPETOWN AND VIRGINIA INITIATIVE PROCESSES

DO between 2.0 and 4.0

mg/L or RTC withAmmonia based Aeration

AnaerobicP release

Anoxicdenitrification

AerobicNitrification and Luxury uptakeDO 0.0 mg/l

ORP < -150 mvDO < .5 mg/LORP between -150 and + 150 mv

RAS

Denitrified MLSS

BNR TREATMENT SCHEMESFIVE-STAGE BARDENPHO PROCESS

DO between 2.0 and 4.0 mg/L or RTC withAmmonia based Aeration

Optional Carbon Source

Reaeration

AnaerobicP release

Anoxicdenitrification

AerobicNitrification and Luxury uptake

Denitrified RAS

Nitrified MLSS

DO 0.0 mg/lORP < -150 m

DO < .5 mg/LORP between -150 and + 150 mv

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NUTRIENTS AND NUTRIENT ANALYSIS IN

WASTEWATER TREATMENT