American Meat InstituteConference on Worker Safety, Human

Resources and the Environment

Kansas City, Missouri

Brian Mulinix, P.E.

Brian Bakke, P.E.

HDR Engineering, Inc.

March 20, 2013

Wastewater Design &

Best Practices

Overview

• Wastewater – what are we treating

• Preliminary Treatment

• Anaerobic Treatment

• Aerobic Treatment

• Nitrogen Removal

• Phosphorus Removal

• Tertiary Treatment

• BOD5

• TSS

• FOG

• TKN

• Phosphorus

• Proteins

• Fats

• Carbohydrates

• Partially-Digested Feed

• Manure

• Urine

What Are We Treating?

OR

OR

What are We Treating?

• Slaughterhouse– Proteins (blood, meat, etc.)

– Fat

– Partially digested feed from stomachs and intestines

– Manure from pens

– Urine from pens, kidneys, bladders, etc.

• Processing– Proteins

– Fat

– Carbohydrates

• Animal Feeding Operations– Manure

– Urine

– Some uneaten feed (protein, carbs, fat/oil)

What Type of Food is Being Treated?

Example Protein Fat Carbohydrates

Slaughterhouse � �

Processing

• Hams Some Some � (from the pickle liquor)

• Bacon Little � �(from the pickle liquor)

• Cooked Sausage Little �

• Chicken-Fried Steaks � � (from the breading)

Rendering � �

Ready-to-Eat Foods Some Some � (noodles, sauces, seasonings, etc…)

Pretreatment Can Shift Type of Food

• DAF reduces fat and some protein

• Ferric pretreatment greatly reduces both fat and

protein

• Many carbohydrates

– Go into “true solution”

– Unaffected by physical or chemical pretreatment

Determine Waste Loads from Food

• Protein BOD5 = TKN x 6.25 x 0.8

• Fat BOD5 = FOG x ( 1.7± )

• Carbohydrate BOD5 =

Total BOD5 – Protein BOD5 – Fat BOD5

Why is Type of Food Important?

• Anaerobic Sludge Production

• pH Buffering

– Proteins make their own alkalinity

– Fats and carbs require alkalinity for buffering

• Nutrient Requirements

– Proteins are a complete food source

– Fats and carbs are deficient in nutrients and

micronutrients

• Different Physical Characteristics

– Fats may coat media, float

Fat Protein Carbs

1 1.5 - 2 4 - 5

Swine Farms are Slightly Different

• Swine farm waste is similar to human waste without

the dilution water

• Virtually everything has been through digestive or

urinary tract

• Pigs have utilized much of readily-digestible food

(energy), leaving less easily-digestible to treat

What is Your Discharge Requirement?

• Municipality

– Limits specific to system

– Surcharges

• Land Application

– Agronomic rates

• Direct Discharge

– Effluent guidelines

– Nutrient limits

PRETREATMENT

Screening

• Remove solid materials, prevent avoidable BOD

and TSS

• Types:

– Static Screens

– Vibrating Screens

– Rotary Screens

– Channel Screens

Gravity Clarifiers

Removal

BOD 20-30%

TSS 30-40%

TKN 10-20%

FOG 50-60%

Dissolved Air Flotation

Removal

Without

Chemicals

With

Chemicals

BOD 30-40% 60-80%

TSS 50-60% 70-80%

TKN 20-30% 40-60%

FOG 50-70% 70-90%

ANAEROBIC TREATMENT

Anaerobic Treatment – A Marvelous Tool

• Reduce CBOD5 by 85-90%

• Reduce TSS by 70-80%

• Biogas produced containing 74±%

• Accept/treat shock organic loads

• Serves as equalization

• Accomplishes with minimal energy required and

minimal sludge production

Anaerobic Degradation of Organic Materials

Acid-Forming

Bacteria

Methane-Forming

BacteriaComplex

Organics

Organic

Acids

Methane +

CO2 + small

amt. Cell Mass

Waste Conversion

(minimal energy lost,

minimal BOD reduction)

Waste Stabilization

(waste energy converted to

methane energy, big BOD

reduction)

Anaerobic Treatment Technologies

• Low Rate

– Anaerobic lagoon

• Medium Rate

– Anaerobic contact system

– Anaerobic SBR

• High Rate

– Upflow Anaerobic Sludge Bed (UASB)

– Anaerobic filters; upflow, downflow, expanded bed

– Hybrids

Anaerobic Treatment Comparison

Low Rate Medium Rate High Rate

Process/Reactor Lagoon

Contact

process ASBR UASB Filters

Loading,

lbs BOD5/1000 ft3/day 15 – 30 60 – 160 60 – 375 >160 160 - 625

HRT, days 3.5 – 15 1 – 10 0.5 – 10 0.25 – 1.5 0.5 – 2.0

SRT, daysunknown,

but long>20 >30 >100 30-100

In summary, anaerobic lagoon is lightly loaded with a long detention

time and sludge age – and all the more robust for it

Covered Anaerobic Lagoon

Storm Water Collection

Synthetic or

Natural Cover

Peripheral Biogas

Collection

Design Considerations / Common Operating

Problems

• Solids Accumulation

– FOG at lagoon < 350 mg/L

– Prevent sand, mud, grit, paunch manure, pen waste,

truck bedding, etcL keep out of lagoon

– Measure/plot grease cover and settled sludge

thickness Spring, Summer and Fall

– Remove sludge every Fall to maximize active volume

– < 15% of WAS digests in lagoon, serves more for

thickening; remove WAS sent 1-2X/year

Design Considerations / Common Operating

Problems (cont.)

• Anaerobic Temperatures

– Ideally 95°F

– Can go as low 82-86°F, or lower for shorter periods

• Chemicals

– Chlorides: sudden swings of > 1,200 mg/L may

disrupt anaerobic treatment

• Processing plants with brine chills, pickle liquors

• Beef plants with brine hide curing

Design Considerations / Common Operating

Problems (cont.)

• Chemicals (cont.)

– Sulfates/Sulfides

• Sulfates typically from water supply– Ferric sulfate in pretreatment

– Processing mucosa

– Tannery wastewater

• Sulfates in anaerobic influent reduced to hydrogen sulfide– Reduces methane generation

– At high concentrations can be toxic to methanogens

» Rule of thumb – COD:S < 4:1

– Most in effluent, but released in biogas (depending on pH and temperature)

– For every 26 mg/L H2S in the liquid, 1% in gas phase (35⁰C)

– For each 1 mg/L sulfide in effluent, requires 2 mg/L of dissolved oxygen to oxide back to sulfate

– Can use ferric/ferrous to tie up sulfide

Design Considerations / Common Operating

Problems (cont.)

• Chemicals (cont.)

– Quaternary Ammonium Compounds (Quat)

• Inhibitory levels at 5-15 mg/L active ingred.

– Macronutrients: nitrogen, phosphorus, potassium

– Micronutrients

• Cobalt, copper, manganese, molybdenum, nickel

(0.1 mg/L deficient)

• Iron (1.0 mg/L deficient)

Meat Processing Plant

Anaerobic Lagoon Effluent

30

40

50

60

70

80

90

100

0

500

1000

1500

2000

3/4

/07

4/1

5/0

7

5/2

7/0

7

7/8

/07

8/1

9/0

7

9/3

0/0

7

11/1

1/0

7

12/2

3/0

7

2/3

/08

3/1

6/0

8

4/2

7/0

8

6/8

/08

7/2

0/0

8

8/3

1/0

8

10/1

2/0

8

11/2

3/0

8

1/4

/09

2/1

5/0

9

3/2

9/0

9

5/1

0/0

9

6/2

1/0

9

8/2

/09

9/1

3/0

9

10/2

5/0

9

12/6

/09

1/1

7/1

0

2/2

8/1

0

4/1

1/1

0

5/2

3/1

0

Tem

pera

ture

(°F

)

CB

OD

(m

g/L

)

CBOD mg/l Volatile Acids TEMP (ºF)

Micronutrient

Addition

Reactions to upsets, not

causes:

• Drop in biogas

production

• Low pH

• Increase in ORP

• High volatile acids

• Increased

acid:alkalinity ratio

If performing poorly,

check:

• New plant operations,

like processing mucosa

• Temperature

• Quats

• Sudden chloride swings

• Nutrients and

micronutrients

Anaerobic Lagoon Operating Problems

AEROBIC LAGOON TREATMENT

Aerated Lagoons/Basins

• Hydraulic and Sludge detention

time 1-5 days

• Detention time, not oxygen

transfer rate dictates size

• As CBOD5 drops, TSS climbs due

to microorganism growth

Advantages

• Simple to operate

• No sludge to handle

• BOD reduction

• 50% in winter

• ≥75% in summer

• Convert anaerobic effluent to aerobic

• Nitrify NH3 under certain conditions

Disadvantages

• Electrical energy req’d

• TSS increase

• Nitrification requires

• Longer detention time

• Temperatures > 50°F

• Small influent flows

require vertical-wall

tanks

Aerated Lagoons/Basins

ACTIVATED SLUDGE – NITROGEN REMOVAL

Activated Sludge Process

Aeration

Clarification

Biomass

Recycle

Biomass

Waste

Activated Sludge is like a loop with no beginning and no end

• Continuous or semi-continuous

– CBOD oxidation

– Nitrification

• Represents most wide-spread

used in meat and poultry

industries

• Conversion into settleable

solids

• Develop ideal biomass

• Balance of floc and filament-

forming organisms

Influent

Effluent

BOD Only Activated Sludge

• Design Parameters to consider

– Dissolved oxygen supply – Maintain 2.0 mg/L DO

– Alkalinity – Maintain pH 6.5 – 7.9

– Detention/contact time – 4 to 8 hours

– Mixed Liquor Concentration – 2,000 to 3,000 mg/L

– Oxygen Uptake Rate – 40 to 50 mg/L/hour

– Sludge age – 1 to 3 days

– Temperature range – 10 to 30 deg. C.

Consumes:

1.1 g O2 / g BOD

Typical Meat Industry Activated Sludge

Aeration Basin Final

Clarification

RAS

WAS

Anaerobic Lagoon

Anaerobic Influent Anaerobic Effluent

Pork/Beef Poultry Meat Proc. Pork/Beef Poultry Meat Proc.

CBOD5 (mg/L) 1200-1300 600-1800 600-1600 200-400 150-250 150-250

TKN (mg/L) 120-300 60-180 50-150 110-270 55-160 45-135

Nitrate/Nitrite (mg/L) ≤4.0 ≤4.0 ≤4.0 0.0 0.0 0.0

Phosphorus (mg/L) 20-50 15-30 20-45 18-45 13.5-27 18-40

BOD:N:P 100:10:1.67 100:10:1.67 100:10:3.0 100:60:10 100:50:10 100:40:14

Ammonia Nitrification

• 2-step conversion

– Ammonia to Nitrite - Nitrosomonas

– Nitrite to Nitrate - Nitrobacter

• Design Parameters to consider

– Dissolved oxygen supply – Maintain 2.0 mg/L DO

– Alkalinity – Maintain pH 6.5 – 7.9

– Detention/contact time – 4 to 24 hours

– Mixed Liquor Concentration – 3,000 to 5,000 mg/L

– Oxygen Uptake Rate – 40 to 50 mg/L/hour

– Sludge age – 8 to 15 days depending on temperature

– Temperature range – 10 to 30 deg. C.

Consumes:

4.57 g O2 / g NH4-N

7.14 g Alk CaCO3 / g NH4-N

Traditional Nitrification/Denitrification

25% O225% O2

40% Carbon (BOD)

40% Carbon (BOD)

60% Carbon

(BOD)

60% Carbon

(BOD)

Nitrification-Aerobic

Denitrification-Anoxic

4.57 g O2/g NH4-N oxidized

3.5-6 g COD/g NO3-N reduced

7.14 g CaCO3/g NH4-N oxidized

recover 3.57 g CaCO3/g NO3-N reduced

1 mol Nitrite

(NO2-)

1 mol Nitrite

(NO2-)

1 mol Nitrate

(NO3-)

½ mol Nitrogen Gas

(N2)

1 mol Ammonia

(NH3/ NH4 +)

Autotrophs

Heterotrophs

75% O275% O2

Nitrogen Removal Processes

• Single Stage Nitrification-Denitrification

• Simultaneous/Combined Nitrification Denitrification

• Sequential BOD-Nitrification-Denitrification

• Biological Options

– Suspended Growth

– Fixed Biofilm

Nitrogen Removal Processes - Classic Zoned

Wuhrman

Ludzack-Ettinger

Modified Ludzack Etinger

(MLE Process)

Bardenpho

(4 stage Phoredox)

Step FeedTilmann WRP, Los Angeles

Effluent:

NH4-N < 1 mg/L

TN < 10 mg/L

Nitrif/Denitrif: +70% TN Removal

Modified Ludzack-Ettinger (MLE) system

Aeration

Basin Final

Clarifiers

RAS (1Q)

WAS

Anoxic

Basin

Mixed Liquor Return (4Q)

(nitrate source)

From

Anaerobic

Lagoon

TN

200 mg/LTN

40mg/L

Carbon

Alkalinity

0%

20%

40%

60%

80%

100%

0 2 4 6 8 10

Recycle Ratio (RAS + MLSS)

Denitrification vs Recycle

Nitrif/Denitrif: 6-8 mg/L Effluent TN

Aeration

Basin Final

Clarifiers

RAS (1Q)WAS

Anoxic

Basin

Mixed Liquor Return (4Q)

(nitrate source)

From

Anaerobic

Lagoon

4-Stage Bardenpho system

TN

200 mg/LTN

7 mg/L

Carbon,

Alkalinity Post-Anoxic

BasinReaeration

Basin

Carbon

TN

40 mg/L

Pork Plant – Effluent Nitrogen

0

5

10

15

20

25

30

35

40

45

50

1-Nov-08 3-Jan-09 7-Mar-09 9-May-09 11-Jul-09 12-Sep-09 14-Nov-09 16-Jan-10

Tota

l Nit

rog

en, m

g/L

Effluent TN

Probably lost nitrification

Switched from Final

Clarifier

to UF Membranes

Influent TKN averaged 199 mg/l

Simultaneous Nitrification/Denitrification

• Biological process occurring concurrently in same

reactor

• Relies on dynamic balance of DO/BOD/NH3

• Utilizes control of aeration by DO or ammonia

concentration

• Reduces oxygen requirements and recovers

alkalinity

• Total nitrogen removal

Simultaneous Nit/Denit

25% O2

40% Carbon

60% Carbon

Nitrification-AerobicDenitrification-Anoxic

1 mol Nitrite

(NO2-)

1 mol Nitrite

(NO2-)

1 mol Nitrate

(NO3-)

½ mol Nitrogen Gas

(N2)

1 mol Ammonia

(NH3/ NH4+)

AutotrophsHeterotrophs

75% O2

3.43 g O2/g NH4-N oxidized

2.1-3.6 g COD/g NO3-N reduced

5.7 g CaCO3/g NH4-N oxidized

recover 2.38 g CaCO3/g NO2-N reduced

Nitrogen Removal Simultaneous

SBR

Oxidation Ditch

Biodenitro

– Cyclic Aeration

Two Zone Activated

Sludge with DO Control

Effluent:

NH4-N < 4 mg/L

TN < 6 mg/L

Simultaneous Nit/Denit

SND

Basin Final

Clarifiers

RAS (1Q)

WAS

From

Anaerobic

Lagoon

Carbon

Alkalinity Post

Aeration

NH3 / DO

Control

• Target effluent NH3 in first stage

• Target DO in first stage 0.01-0.15 mg/L

• Denitrification dependent on DO control and BOD availability

Potential Advantages

• Elimination of separate tanks, internal recycle

• Simpler process design

• Reduction of carbon, oxygen, energy, and alkalinity consumption

Potential Disadvantages

• Limited controlled aspects of the process

• Floc sizes

• Internal COD storage

• DO profile within floc

• Slower Growth Rates

• Larger Tank Sizes

• Sludge bulking, filamentous bacteria growth

• Complex instrumentation

Simultaneous Nit/Denit

Anammox

25% O2

40% Carbon

Nitrification-Aerobic

Denitrification-Anoxic

1.83 g O2/g NH3-N oxidized

0 g COD/g NO2-N reduced

3.1 g CaCO3 /g NH3-N oxidized

1 mol Nitrite

(NO2-)

1 mol Nitrite

(NO2-)

1 mol Nitrate

(NO3-)

½ mol Nitrogen Gas

(N2)

1 mol Ammonia

(NH3/ NH4+)

Autotrophs

Heterotrophs

40-50% O275% O2

60% Carbon

Definition

Developed in EuropeBacteria• Autrophic – Use CO2 as Carbon

Growth Conditions• Anaerobic/Anoxic• Temperature 20-35°C• Very slow growers –

– Long sludge age > 30 days

• NH4+ : NO2- ratio ≈ 1 : 1.32 – pH (neutral range)

– Nitrite (maintain at <40 mg/L)

– Free Ammonia (maintain at <10 mg/L)

• Once Grown Very Stable - Can be stored for months with no food.

Anammox Providers

• Paques BV

– Upflow gravity separation

• Anita MoxTM by Veolia Water Technologies

– Plastic biofilm carriers

– Similar to MBBR

• DEMON® by World Water Works

– WAS cyclone separation

– SBR reactor

Anammox (DEMON®)

Operational Philosophy

1 process cycle of the

DEMON involves 4 time-

controlled phases:

• Aeration phase

• Fill / React phase

• Settling phase

• Discharge phase

Standard Effluent

90% removal NH4-N

10% production NO3-N

80% removal TN

Full Scale Operation

• Regular sampling

• Sensors: pH, DO, conductivity,

NH3-N

• Regular Operation

– DO range of 0.3-0.4 mg/L

(during aeration phase)

– pH typically 7.0

• Avoidance nitrite accumulation

• Downtimes

DEMON® Design Requirements

• Pretreatment

– Most BOD, TSS removed

– Pre-storage tank (6-12 hrs HRT)

• Design parameters

– Total/soluble COD, TKN, NH3-N, Alkalinity, PO4-P,

TSS, Temperature, pH

– Flow (aver/max); sludge processing

• Tank reactor

– Operates as SBR, but can be continuous flow

DEMON® Major Components

Seed Sludge Aeration System

Instruments & Controls

Tank

Blowers Decanter Mixer Cyclone

Comparison

N2

CO2 emissions > 4.7 t CO2/t N

NO3

C-source2.3 lb

Methanol/lb N

NH4

Energy 1.27 kWh/lb N

Nitrification/Denitrification

N2

CO2 reduction -0.4 t CO2/t N

NO2 / NH4

C-source0 lb

Methanol/lb N

NH4

Energy 0.50 kWh/lb N

DEMON®-system

Demon Results - Sidestream

Heidelberg, Germany

126,000 gal/day; 1,300 mg/L TN

PHOSPHORUS REMOVAL

Biological Phosphorus Removal

• Many Process Options

• Anaerobic Zone key to process

– Grow Phosphorus Accumulating Organisms (PAOs)

• Typically achieves <1.0 mg/L

• High influent Sol BOD/P is required

– carbon/VFA addition via fermentation

• Process stability is key. Conditions that favor the

right PAO populations are need to be understood

Biological Phosphorus Removal

Modified (5-stage) Bardenpho

UCT

Modified UCT

VIP (Virginia

Initiative

Process)

Effluent:

TP < 1 mg/L

OP < 0.5mg/L

Chemical Phosphorus Removal

• Chemical Options

– Ferric Salts (Ferric Chloride, Ferrous Chloride)

– Alum

– Sodium Aluminate

– Lime

• Reaction: FeCl3 & PO4 FePO4 & 3Cl

• Dosage: Theory : 5.24 lbs FeCl3 / lb P

Actual: 10.48 lbs FeCl3 / lb P

Rate: 3.1 gallons 30% FeCl3 / lb P

Typical Chemical Treatment Opportunities

Primary Secondary Tertiary Polish

Solids

Processing

TERTIARY TREATMENT

Tertiary Treatment

• Treatment Goal – Remove additional TSS, TN, TP

not captured in secondary treatment processes.

• Simple TSS Removal

– Tertiary Clarifier

– Cloth Filter Disk

– Sand Filter

• More Complex

– Membrane Bioreactor

– Ultra Filtration

– RO

TN Removal • Biologically Active Filter (BAF)

• Submerged Biofilter

American Meat InstituteConference on Worker Safety, Human

Resources and the Environment

Kansas City, Missouri

Brian Mulinix, P.E.

Brian Bakke, P.E.

HDR Engineering, Inc.

March 20, 2013

Questions?

Wastewater Design &

Best Practices