© Matias Vanotti,

ARS-USDA

Recovery of Phosphate and Ammonia from Animal

Waste: A New Paradigm in Agriculture

USDA-ARS Coastal Plains Research Center

Florence, South Carolina, USA

Matias Vanotti

ReUseWaste Kick Off Meeting

University of Copenhagen, Sept 24-26, 2012

© Matias Vanotti,

ARS-USDA

© Matias Vanotti,

ARS-USDA

Concentration of swine production

Concentration of pig production in USA

North Carolina produces

approximately 750 million

chickens, 40 million turkeys,

3.5 billion table eggs, and

19 million hogs per year.

Animal Manure – Surplus N and P in North Carolina, USA

© Matias Vanotti,

ARS-USDA

Percent of Agronomic Crop and Forage Phosphorus Needs

Supplied by Recoverable Plant Available Manure Phosphorus at the County

Level in North Carolina

0 - 10

10 - 40

40 - 70

70 - 100

> 100 Source: Barker & Zublena

Animal Manure – Excess P in North Carolina

© Matias Vanotti,

ARS-USDA

P

N K

Source: IFDC

Global Fertilizer Prices

© Matias Vanotti,

ARS-USDA

Fertilizers

28%

Diesel

27%

Electricity

21%

Natural Gas

4%

Gasoline

9%

Pesticides

6%

LP Gas

5%

Escalating U.S. Fertilizer Costs

20

10

20

00

19

90

19

80

19

70

19

60

19

500

100

200

300

400

500

600

Year

Cost

per

ton (

$) Anhydrous

nitrogen

Potash

Energy and Agriculture

© Matias Vanotti,

ARS-USDA

Presentation outline: Nutrient recovery

technologies at USDA-ARS

• Soluble P extraction after buffer removal

• Solids-liquid separation with polymers

• Quick wash P recovery from solid manures

• Biochar P fertilizer

• N recovery with membranes

Recovery of Phosphate from Wastewater

On-farm

Phosphorus Mining

from Manure

© Matias Vanotti,

ARS-USDA

Phosphorus Removal Process

Buffer Systems in Animal Manure

Urea Hydrolysis

CO(NH2)2 + 2H2O ---> 2NH4+ + CO3

2-

Alkalinity

Ammoniacal

Nitrogen

© Matias Vanotti,

ARS-USDA

Buffer Systems Make Difficult the

Precipitation of Phosphorus

in Liquid Manure:

Carbonate Buffer System prevents calcium

phosphate formation

Ca(OH)2 + Ca(HCO3)2 2CaCO3 + 2H2O (2)

Ammonium – Ammonia Buffer System prevents

calcium phosphate formation

Ca(OH)2 + 2NH4

+ NH3 + Ca++ + 2H2O (3)

High Amount of Chemical Required © Matias Vanotti,

ARS-USDA

Phosphorus Removal Process

• The addition of Ca(OH)2 (or Mg) after

removal of natural buffers rapidly increases

the pH, which promotes precipitation of

phosphate with small amounts of chemical

added.

Vanotti et al. Extraction of soluble phosphorus from swine wastewater. Trans.

ASAE 46:1665-1674. © Matias Vanotti,

ARS-USDA

Phosphorus Removal Concept: Elimination of Buffer System with Biological Treatment

NITRIFICATION

BIOREACTOR

LIME OR

CA/MG HYDROXIDE

DISPENSER

PHOSPHORUS

SEPARATION

REACTOR EFFLUENT

WITH

NITRATE

PHOSPHATE

PRECIPITATE

INFLUENT WITH

AMMONIA

PHOSPHORUS

ALKALINITY

Wastewater Treatment System Vanotti et al. U.S. Patent 6,893,567 B1

© Matias Vanotti,

ARS-USDA

Phosphorus recovery from swine wastewaterusing Calcium Hydroxide

1 5 10

Calcium hydroxide rates (Moles of Ca added/ mol P)

0

10

20

30

40

50

60

P removed from liquid (mg/L)

with nitrification control

100%

© Matias Vanotti,

ARS-USDA

Calcium

Phosphate

Solid-liquid

Separation

Module

Nitrification

Denitrification

Module

Phosphorus

Removal

Module

Swine

Houses Separated

solids Reuse

Effluent

On-Farm Treatment System

© Matias Vanotti,

ARS-USDA

Goshen Ridge Farm, Duplin Co., NC

4,360-finishing pig production unit

Solid-liquid

Separation

N treatment

Phosphorus

Recovery Module

Raw ManureTreated: 39 m3/day

Manure treatment system developed to replace swine lagoons in

North Carolina. NC Attorney General – Smithfield Foods/PSF

Agreement

© Matias Vanotti,

ARS-USDA

Soluble phosphorus separation and

bagging of the calcium phosphate

P separation module

© Matias Vanotti,

ARS-USDA

Dewatering and bagging of calcium phosphate

Recovered P from sludge = 99.5%

Vanotti et al., Biores. Technol. 98:3184-3194

Constituent Percentage

P2O5 24.4% ± 4.5%

Calcium 27.3 %

Potassium 0.9 %

Magnesium 1.8 %

Chemical Composition

Recovered Phosphates

99% plant available (standard citrate test)

© Matias Vanotti,

ARS-USDA

Agronomic Effectiveness of Phosphates

Recovered from Manure

Green-house testing at Florence Interaction with Industry

Production of fertilizer pellets

Concentration of pathogen indicator in manure liquid (bacterial

count/mL)

1

10

100

1000

10000

100000

1000000

Manure flush Separated

liquid

Biological N

removal

P effluent

EnterococciTotal Coliforms

THE HIGH PROCESS pH DISINFECTS THE EFFLUENT

SUMMARY

• Phosphorus is selectively precipitated using lime after

carbonate and ammonia buffers are reduced with

biological N removal.

• The precipitate is calcium phosphate (~ 24% P2O5)

that can be reused as plant fertilizer.

• The high process pH also disinfects the effluent (> 4

logs)

Environmentally Superior Technology (EST)

Standards for New Swine Operations in NC

Substantially eliminate:

1. ammonia emissions

2. odor emissions

3. pathogens

4. nutrient (N & P) surplus

5. heavy metal contamination

Lessons learned after testing 18 technologies at full-scale:

a combination of two or more simple processes

are needed to meet all environmental standards

Diet Manipulation Liquid System

Solid Separation

Screen 5-25%

Enhanced Separation

Polymer Flocculation> 90%

Vermicompost

High Solids

Anaerobic Digestion

Pelletize

Plastic composites

Biochars

Oil

Composting

Plant Growth Media

Dry Systems

High Rise/ Deep bedding/

Belt System

Methane Digestion

Algae Biomass (biodiesel)

Phosphorus Precipitation

(Struvite, Calcium Phosphate)

Constructed Wetland

Rice/ Soybeans

Nitrification, DN, Anammox

(Transform Ammonia to Nitrate, N2)

Gasification

On Farm Liquid Treatment and

Application to Cropland

Solid & Nutrients Moved

from Farm, Value-added Products Ethanol

Phosphorus Products

Ammonia Recovery

(Membranes)

Liquid

Ammonia

NPPC Task Force Other Utilization Activities, Vanotti 2001, revised 2009

EST

EST © Matias Vanotti,

ARS-USDA

Lower Cost, Second Generation

Technology

NC Attorney General – Smithfield Foods

Environmental Enhancement Program

TREATED

EFFLUENT

PHOSPHORUS SEPARATION

REACTOR UNIT

B

BLOWER

PAM

P

DENITRIFICATION

UNIT

CLARIFICATION

UNIT

NITRIFICATION

BIOREACTOR UNIT

RETURN SLUDGE

CONFINED LIVESTOCK

SWINE

MANURE (SM)

SOLID SEPARATION

UNIT 1

RECYCLE

PHOSPHATE

PRECIPITATE

SLUDGE (PS)

P

M

HOMOGENIZATION

TANK

MIXER

PAM

DEWATERED PHOSPHORUS

SLUDGE

DEWATERED SWINE MANURE

& PHOSPHORUS

PRECIPITATE

SOLID SEPARATION

UNIT 2

P

SECOND GENERATION WITH SIMULTANEOUS SOLID-LIQUID

SEPARATION OF SWINE MANURE AND PHOSPHORUS PRECIPITATE

Vanotti et al. (2010), U.S. Patent 7674379

Phosphorus removal module - continuous flow

Application of lime to pH 9.5 and settling of calcium phosphate

Small P reactor (~ 1 m3 for 5400 pigs)

© Matias Vanotti,

ARS-USDA

Solid-liquid separation of manure and

phosphorus with flocculation

High-capacity rotary press

Capture of P, organic N, Cu & Zn

Solids

N

P © Matias Vanotti,

ARS-USDA

FLOCCULATION WITH POLYMERS INCREASES

SOLIDS SEPARATION EFFICIENCIES

• PAM Applications: municipal, food processing, soil erosion, animal waste

• Absorb and bridge colloidal suspended particles into flocs

• Effective at low dosage

• Natural Polymers: Chitosan, Tanins

+

+

+

+

+

+

+

++

+

+

+

+

+

+

+

+

+

+

+

+

+

+

++

+

++

++

PAM Flocculation

Vanotti et al., Transactions of the ASAE, 1999, 2002, 2005 © Matias Vanotti,

ARS-USDA

Model: Centralized Plant for Processing of Separated Manure Solids

Generation of Value Added Products though Composting

© Matias Vanotti,

ARS-USDA

Centralized Solids Processing Facility (Composting)

• Conserved the separated N and P

• Manure transformed into Class A compost

• Processed into plant growth media

Mass

Balance

%

Loss

% Recovery

Nitrogen 3.5 96.5

Phosphorus 0 100

Nutrient Stabilization & Recovery

Solids Processing Facility

95.6Total Copper

99.6Total Zinc

101.2Total Phosphorus

97Total Nitrogen

56.6 %Total Carbon

28.4Material Volume

55.5 %Material Weight

© Matias Vanotti,

ARS-USDA

Production of high-value plant growth media

and organic fertilizers from composted

manure

© Matias Vanotti,

ARS-USDA

Another Phosphorus Recovery Technology

Quick Wash Process

Manure is washed with mild acids and then

the phosphorus is recovered as solid

© Matias Vanotti,

ARS-USDA

Poultry Litter

Phosphorus Removal and Recovery Quick Wash Process

USDA - ARS

Washed

Litter

P extraction

Acidic solution

Poultry

Litter

P removal

Alkaline pH

P precipitation

enhancement

Recovered P

Liquid

Effluent

1 2 3

© Matias Vanotti,

ARS-USDA

Manure Wash Pilot Experiment

Solid Manure

+ Water

+ Acid

Washed

Solids

Lime

Extracted

Phosphorus

Solids

Liquid with Low

Suspended Solids

+ Soluble Phosphorus

Liquid to

Recycle

1 2

Flocculant

3

© Matias Vanotti,

ARS-USDA

.

P recovered from

poultry litter Poultry litter after

quick wash

Quick Wash

Products

© Matias Vanotti,

ARS-USDA

Quick Wash for Pig Manure (Steps 2 & 3)

Process was optimized at pH 8

0 2 4 6 8 10 12 140

100

200

300

0

20

40

60

80

100

TP RecoveredTP in Liquid Extract

pH

To

tal P

, m

g/L

To

tal P

Reco

vere

d, %

pH after step 1 = 4.3, then adjusted by addition of hydrated lime [2% Ca(OH)2] % TP Recovered = (P recovered /Initial P in fresh swine manure) x 100 Initial P in pig manure = 7.1 g/kg (30% solids)

© Matias Vanotti,

ARS-USDA

Quick Wash for Pig Manure – Steps 2 & 3

TP recovery was greatly improved with anionic

PAM application

Flocculant = anionic polyacrylamide polymer applied at 7 mg/L

3 4 5 6 7 8 9 10 11 12 13 140

20

40

60

80

100No Flocculant

With Flocculant

pH

To

tal P

Reco

vere

d,

%

Quick Wash Process

Component of a Manure Management System

Land application

• Washed manure residue with higher N:P ratio

Nutrient transfer program

• Transport of a concentrated P material is more

effective

5-year Project at USDA-ARS Florence, SC (2010-2015): Innovative Bioresource Management Technologies for Enhanced Environmental Quality and Value Optimization.

P-Fertilizer

Treated Water

CH4, CO, H2, etc.

Obj. 3: Impacted Riparian Buffers

3a. N2O Emission Assessment 3b. Microbial Assessment

3c. Biochar Treatment

Obj. 2: Thermochemical

Conversion Technologies

2b. Combustible Gas & Biochar Production 2d. “Designer Biochar” Production

Manure

2a. Feedstock Conditioning

2a. Feedstock Characterization

1h. Microbial Assessment

2b. Structure & Materials Testing

1b. Solid-Liquid Separation 1c. N-removal 1e. P-extraction

Obj. 1: Advanced Management

Systems

1g. NH3 and GHG Assessment

1d. NH3 Recovery

Obj. 4: Byproduct Uses

4b. Improve Soil Fertility 4c. Improve Crop Production

4a. Contaminant Adsorbant

Legend

Method/Assessment

Physical Process

Information

Separated Swine Solids 1a. Facilitate Adoption

2b. Pelletizing

N-Fertilizer

Pelleted Fertilizer

Biochars produced from different feedstocks

and at high/low temperatures

• Biochar pyrolyzed at high/low temperatures will have different structural chemistries

13C Nuclear Magnetic

Resonance spectra of

Pecan biochar

Ground pecan shell

•Biochar can be made

from various crop and manure feedstocks

Pyrolysis Reactor Swine manure

© Matias Vanotti,

ARS-USDA

Figure 1. Ryegrass growth response curve to chemical P fertilization

and yield response to P added via livestock biochar (From Hunt and

Cantrell, USDA-ARS, Florence. )

Manure Biochars as P fertilizer

5.0

5.5

6.0

6.5

7.0

7.5

8.0

8.5

9.0

9.5

10.0

0 50 100 150

Cu

mu

lati

ve R

yegr

ass

Dry

Mat

ter,

g

P, mg P kg soil-1

Chemical Fertilizer

Biochar Mean (350 & 700°C)

Min - Swine 350°C

Max - Chicken 350°C

© Matias Vanotti,

ARS-USDA

Nitrogen Recovery Technology

with Gas Membranes

© Matias Vanotti,

ARS-USDA

Recovery and Concentration of Ammonia

o Ammonia permeation through microporous, hydrophobic

membranes

oReduced ammonia emissions from livestock operations

oProduct is ammonia solution with > 50,000 ppm N

N Recovery from Swine Wastewater

0 5 10 150

1000

2000

3000

4000

5000

6000

7000Decreasing N inSwine Wastewater

Recovered Ammonia Solution

Sampling Day

Am

mo

nia

Co

ncen

trati

on

(p

pm

)

© Matias Vanotti,

ARS-USDA

Liquid Manure Strip solution

(Aqueous acid)

NH4+

H+ + NH3 NH3 + H+

NH4+

Gas-filled pore Hydrophobic

Polymer (e-PTFE)

Microporous gas-permeable membrane:

The ammonia gas (NH3) passes through

For this research we used gas-permeable membranes

made of expanded polytetrafluoroethylene (ePTFE)

(Teflon)

Gas Permeable Membrane Microscopic structure (SEM)

Manufacture of Gas Permeable Membrane

PTFE is stretched to form a strong, porous material

© Matias Vanotti,

ARS-USDA

Tubular or Flat Membrane

Manifold

Air with Ammonia

Acidic Liquid

Membrane pores NH

3

H + NH 4

+

Tubular or Flat Membrane

Manifold Submerged in the

Wastewater

Dirty Liquid with Ammonia

Acidic Liquid Ammonium Salt Fertilizer

Membrane Pores NH

3

H + NH 4 +

Concept of Ammonia Capture from

Wastewater using Gas Permeable Membrane

© Matias Vanotti,

ARS-USDA

TUBULAR MEMBRANES Removal of NH3 from Liquid Manure Using Gas-Permeable

Membranes

Swine

Manure

© Matias Vanotti,

ARS-USDA

© Matias Vanotti,

ARS-USDA 0 14 28 42 56 70 84 98

0500

10001500

5000

15000

25000

35000

45000

55000

NH4-N Recovered in membrane manifold

NH4-N Removed from liquid swine manure

Sampling Time (days)

NH

4-N

co

ncen

trati

on

(mg

L-1

)

Recovery and Concentration of Ammonia from

Liquid Swine Manure using Gas Membranes

(10 batches using same stripping solution)

CONFINEDLIVESTOCK

RAWWASTE

MEMBRANE MANIFOLD SYSTEM

Anaerobic Livestock Wastewater Lagoon withAmmonia Recovery System

RECOVEREDAMMONIA

pH

FLOAT

Retrofit of manure storage units to harvest the ammonia

Vanotti et al. 2011. US Patent SN 13/164,363

© Matias Vanotti, ARS-USDA

Nutrient Recovery System (N and P)

TREATED

EFFLUENT

AMMONIA &

PHOSPHORUS

SEPARATION REACTOR

P

PHOSPHORUS

PRECIPITATEDSLUDGE

CONFINEDLIVESTOCK

SWINE

MANURE(SM)

SOLID SEPARATION

UNIT

P

M

HOMOGENEIZATION

TANK

MIXER

DEWATERED MANURE SOLIDS,

PHOSPHORUS & EXTRACTED NITROGEN

P

P

RAW

WASTE

LIME OR

ALKALI

DISPENSER

MEMBRANE

MANIFOLD

RECOVERED AMMONIA

pH

DO

T

© Matias Vanotti, ARS-USDA

© Matias Vanotti,

ARS-USDA

1. The use of gas-permeable membrane technology could

be an effective approach to recover ammonia from

livestock wastewater.

2. A concentrated liquid nitrogen is obtained that can be

re-used in agriculture as a valued fertilizer.

Conclusions – N recovery from liquid

manure

© Matias Vanotti,

ARS-USDA

http://www.ars.usda.gov/saa/cpswprc

© Matias Vanotti,

ARS-USDA