Challenges and Opportunities in Composting Organic Waste · Composting Organic Waste Harold Keener Food, Agricultural and Biological Engineering ... • Look at what’s happened

Challenges and Opportunities in Composting Organic Waste

Harold KeenerFood, Agricultural and Biological Engineering

OARDC/The Ohio State UniversityWooster, OH 44691keener.3 @osu.edu

International Symposium on Climate Change and Food Security in South Asia

Dhaka, Bangladash. August 25-30, 2008.

Challenge

• Challenge today is reducing fossil fuel use. Why:– Fossil fuel use leads to CO2 generation– Limited supply –what going do when exhausted– Economic well being of countries

Dhaka Bangladesh2008 OSU/OARDC 2

Reflective Thoughts on Standard of Living (Keener, 2008)

• Food kcal/person gprotein/person• Energy watts/person• Income $/person• Quality m2/person

In all measures two variables. To increase the measure increase numerator, decrease denominator. Comes to CO2 reduction, may have to face up to reducing denominator


US Policy –mitigate CO2 (HM Keener, 2008)

• Zero Dependence on Foreign Oil within 20-30 years

• Achieve dramatic reductions in net CO2 generation.

1. Renewables- wind & solar (electricity)2. Bio-based economy3. Other Mass transits, etc.

Don’t believe can afford H2 economy. Dhaka Bangladesh2008 OSU/OARDC 4

Bio-based Economy

• An important solution to reducing fossil fuel consumption

{Solar + CO2 + Nutrients} {Raw Chemical Feedstock}

Chemical feedstock replaces petroleum so don’t increase net CO2 release. (possibly even reduce)


Wind,Solar,Bio-Mass• Wind - U.S. electrical needs• Solar – Off the grid, homes both rural and urban. (In Ohio

Amish already use for lighting (DC) low investment. ?? What about microwave cooking in country.

• Bio-mass – Waste recovery ->Need to connect city with food

producer, etc. for nutrients– Algae farms –> C20 hydrocarbons as chemical feedstock

for diesels, plastics, also fraction for food, feed– Plants -> food, feed, fiber, chemical feedstock

(Reduction in livestock numbers)


Composting is important part of Solution

• Aim is to capture nutrients now going to rivers and oceans or atmosphere and reuse these nutrients so we have sustainable system. Avoid new sources of nutrients(N,P,K,…requires excessive energy and cost.)

• Look at what’s happened to fertilizer cost and supply around world. Doubling, trippling cost in United States.


Composting’s Importance• Reduces disease transmission• Stabilizes product-

– eliminates odors & breeding ground for pest• Easy to transport, use, has nutrient value• Provides disease control in plant production

systems• Minimize pollution from runoff, slow

release of nutrients Dhaka Bangladesh2008 OSU/OARDC 8


Composting Process

Water Vapor, CO2 , Heat

Microbes

Oxygen

Fresh Organic Material Stabilized Organic Residue

25-75 % less volume

Science of Composting


Municipal Solid Waste

Manures, Mortality

BioSolids


• MSW:– Mixed MSW (Number decreasing) 15 facilities– Food Waste 138– Yard Trimmings 3316

• BioSolids 250• Farm Waste/Animal Mortality >5000

* Data for 1997.

Composting In USA*

Dhaka Bangladesh2008 12

U.S. Municipal Solid Waste208,000,000 t/yr

Yard Trim m ings18%

Non-Recyclable Paper25%

Other10%Glass

6%

Metals8%

Plastic11%

Recycleable Paper11%

Food Scraps11%

Currently MSW in U.S.: 23% recycled, 7 % composted, 15% burned, 55% land filled

Compost up to 54%Recycle up

to 36%

Residue

OSU/OARDC


Challenges in Composting MSW• Need to be source separated Examples: yard

trimmings, food waste. • Food Waste – Need to use bio-degradable

packaging and eating utensils. • Food Waste – Economics of on site versus off

site

Dhaka Bangladesh2008 OSU/OARDC 14Kaufman et al., 2004, USEPA

Composting of Yard Trimmings

• Over 3200 sites in U.S.• Unknown how many mulch operations• Compost value $20-60/t


Static Pile Composting of Yard Trimmings (PTI, Seattle, Washington)

Compost Systems


Static Pile Composting of Yard Trimmings(Price Barnes, Delaware, Ohio)

Compost Systems


New Milford Farms, Inc./Nestlé USA, Inc.

50,000 50,000 t/yt/y of raw materials :of raw materials :••Yard Yard wastes,Agriculturalwastes,Agricultural wasteswastes

““DistressedDistressed”” Food ProductsFood Products••Food manufacturers and grocery Food manufacturers and grocery stores,damagedstores,damaged, recalled, etc., recalled, etc.

Source Separated OrganicsSource Separated Organics••Food Processors, Grocery StoresFood Processors, Grocery Stores

OperationOperation••Aerated static pilesAerated static piles

••SCARAB windrow turnerSCARAB windrow turner

••Bagged product: Bagged product: HamerHamer form, fill form, fill and sealand seal

••BiofilterBiofilter on exhaust airon exhaust air


Green Mountain System

On Site Food Waste Composting

Earth Tub

• Composting cost per ton high.


Biosolids Use and Disposal 126,000,000 t/yr *

22% Incineration

1% Other

17% Surface Disposal

7% Landfill Cover,

Aggregate 1% Advanced Treatment

52% Land Application

*6,300,000 dt/yr

Ref: USEPA 1999


Direct Land Application Composting in Vessel

Biosolids

Composting in Aerated or Static Windrow

Methane Production

Gas CH4


Aerated Static Pile for Composting Biosolids and Woodchips

(Columbus, Ohio, 2004)

Compost Systems

Biofilter

J. Hoff, 2004

Wedge shaped approach with air pulled through the pile then pushed through a biofilter.


“Ag Bag” used for yard and food waste in California.

Operators claim it is effective in a dryer climate.

Compost Systems

Aerated static pile for composting biosolids/ woodchips in “Ag Bag” did not prove effective in Ohio’s high humidity climate.


Regulations in the U.S.• Process to further reduce pathogens (PFRP) - know as

US EPA 503 regulations. Enacted for biosolids.≥ 55 C for 3 days in-vessel≥ 55 C , 5 turns, 15 days for windrow


Biosolids Issues in USA• Land application lowest cost: $82/dry t (however,

concerns over pathogens, water quality)

• Composting: $173/ dry t (based on cake 22% ds) New separation technology: 30% solids– reduces amendment 38%, reduces cost ???

• Need to lower composting cost. More efficient operations. Static pile versus in-vessel.

• Anaerobic Treatment -> Methane (still by-product generated)

Livestock Waste

• Cattle (Dairy, Beef)• Poultry (Broiler, Caged Layers)• Swine (Sows, Marketing Hogs)


ManureMillion Head t/yr

Market Hogs 60.4 29,200,000Beef Cows 33.4 509,800,000

Market Cattle 14.9 133,500,000Milk Cows 9.1 212,100,000

Caged Layers 334 14,400,000Broilers 8500 31,300,000Turkeys 283 8,500,000

Totals 938,800,000

Livestock

Poultry


Agricultural Waste Issues in USA• Land application has lowest cost (however,

concerns over pathogens, air, water quality. • Transportation of liquid manures beyond 10 km

can exceed value of nutrients in manure.• Some new housing/manure management systems

lend themselves to composting manure.• Need to lower composting cost. • Need to find value added markets for compost.


One million birds use system at DayLay Farms. Manure dries on belt from 70% to 50-55% moisture. Manure goes to compost building.

Manure Belt System with Composting for Poultry

New Technology


Aerated Turned Windrows. (DayLay Farms, Ohio)

Compost Systems

Unamended poultry manure is composted in the first 45 m of the windrow and turned 18 times during the 54-day process.


Turned Windrow Composting of Dairy Manure & Sawdust.

(Sigrist Farms, Ohio)

Using a skid loader to turn manure. The farm has a

turning machine but seldom uses it.

Compost Systems


Sigrist Farms finds screening is essential for marketing a quality

product. Market as a bagged product (about 18 kg per bag) as

Bull Country Compost.

Compost is stored under roof for curing, approximately 6 months. Material is then bagged for marketing.

Compost Systems

Sigrist Farms, Ohio


Turned Windrow Composting of Cattle Manure and Yard Trimmings

(Dan Young Farm, Ohio)Dan Young speaking to a group of farmers, agricultural specialists, university persons at August field day.

Compost turner and water are added to tank. Water addition is

often necessary early in the process if starting with materials less than

60% moisture.

Compost Systems


In-Vessel Forced Aeration System(Paygro, Ohio)

Compost Systems

Composting of cattle manure and food and yard wastes is completed in 21-28 days.

OSU/OARDC Compost 33

Animals placed on absorbing base and being covered over with 2 ft+ of biofilter material.


Windrow after grinding 65 carcasses6-12 in

12 in12 in

15 ft

8ft

Schematic of composting windrow (intact carcass)

2-3' thermometer

Rule of Thumb:• 250'x250' pad will hold

five 15'x200' windrows• 1 windrow will hold ~100

finishing cattleClean sawdust cover

Soiled amendment or used compost

carcass

Grass filtration strips around the perimeterSoil

Lime base

Static Pile Composting of Dead Animalsas an Alternative to Rendering

John Kube, Elanco Animal Health, Greenfield, IN

Compost Systems


Bio-Research Building

200 L aerated reactor vessels

Instrumentation

Optimization of the Process

Laboratory at OSU/OARDC Used in Controlled Pilot Scale Studies on Process Kinetics

4L BioReactors in Incubator

Windrow Composting Research Site at OARDC

36

OARDC Pad – 20,000 sq. ft. concrete, 1-2 % slope. Aeration fans

OARDC

Composting Research at OARDC

• Optimization studies - Nitrogen, Moisture, Airflow, ........... Send specific questions to: [email protected]

• Survival of pathogens in manure during liquid storage or composting. E.coli survival (rough type), E.coli survival (smooth type), Salmonella, Listeria , Cryptosporidium, Mycobacterium paratuberculosis

• Bio degradable plastics



C/N Effect on Decomposition Rate

Study on mixture of paper mill sludge (PS) and broiler litter (BL). Optimum C/N was approximately 35.

Compost temperature = 60 0C.

Ekinci, OARDC, 2001

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0 10 20 30 40 50 60

[C/N]b

Dec

ompo

sitio

n R

ate(

k)(1

/day

)

k(from Equation 10 and 11) k(experimental)

k k e b x= − −max ( )1 2μ

kmax = 0.11b=0.002665

μ = 335.R2 072= .

(b)



Increasing C/N Reduces NH3 Losses

y = -0.0089x + 0.5712= 0.5872

0%

10%

20%

30%

40%

20 30 40 50 60 70Initial CN ratio

N loss (% of initial)

N-Losses during composting dairy manure(% lost of initial amount)

Michel et al., 2004


Effect of Moisture and Operating Temperature on Decomposition Rates

0.00

0.02

0.04

0.06

0.08

0.10

30

35

40

45

50

55

40

50

60

Dec

ompo

sitio

n ra

te,k

, (da

y-1)

Tota

l Mois

ture

Con

tent

, wb.

(%)

Tmeperature (oC)

k=0.0917*e -0.5*[((M-44.51)/18.73)2+((T-57.31)/15.81)2]

R2=0.96

Ekinci, OARDC, 2001

Study on mixture of paper mill sludge (PS) and broiler litter (BL) with C/N = 32. Gaussian function used to describe relationship.



1 m3/ (kgco day) = 22.3 cfm/ (tonco)

Airflow Requirements Control Temperature

Case Study


Acids Evaluated: Acetic Propionic IsobutyricButyric Isovaleric Valeric

Aerobic, Low Airflow Destroys Volatile Acids, Reduces Odor

Wiles et al., 2004

( )

0

5

10

15

20

25

30

35

40

0 50 100 150 200 250 300 350 400 450

T im e (h o u rs )

VFA

Em

issi

ons

(mg)

A c e tic A c id

Prop ion ic A c id

Is obuty r ic A c id

Buty r ic A c id

Is ov a ler ic A c id

V aler ic A c id

Intermittent Aeration Run 173-99 Swine/Sawdust Mixture

0

5

1 0

1 5

2 0

2 5

3 0

3 5

4 0

0 1 0 0 2 0 0 3 0 0 4 0 0 5 0 0

VFA

Em

issi

ons

(mg)

A c e t ic A c id

Pr o p io n ic A c id

Is o b u ty r ic A c id

B u ty r ic A c id

Is o v a le r ic A c id

V a le r ic A c id

Continuous Aeration Run 173-99 Swine/Sawdust Mixture


Dry Matter Loss

• Stir 1 time/week 15.5% dm loss• Stir 3 times/week 18.1% dm loss

• No water added 17.6% dm loss• Add water 36.1% dm loss



Bioreactor System

Flow restrictor system(air 100 ±3 ml/min)

Data collection computer

Bioreactor incubators

CO2, O2 and temperaturemeasurement, calibration

and data acquisition.

Water condenser and ammonia trap (4° C.)

OARDC/OSU Study on Pathogens

[email protected]


Mycobacterium paratuberculosisSawdust Compost 55°C

Straw Compost 55°C

Sawdust Pack 25°C

Straw Pack 25°C

Lagoon storage 25°C

0

1

2

3

0 3 7 14 28 56Day

Posi

tive

Rep

licat

es

*

* *

For detailed information contact [email protected]

OARDC/OSU Study on Pathogens

[email protected]


Mixing Dairy Cattle Manure

For excel spreadsheet go towww.oardc.ohio-state.edu/ocamm/COEC.htm

ITEM Vol Mass Moist C N C/NRatio Ratio wb db db db

MATERIAL dec dec % % %dairy (free stall) 1.00 1.00 81.2 44.6 2.64 16.9sawdust 1.17 0.33 16.0 49.8 0.16 311.0recycle site compost 0.00 0.00 44.6 43.5 1.50 29.0water 0.00 0.00 1.0 0.0 0.00 0.00

Initial Mix 64.9 47.7 1.16 41.2

Using Compost for Growing Plants

• Provides Nutrients• Improves Soil Structure• Provides Pathogen control

– Organic matter must be decomposed “adequately”(prevent N immobilization, pathogen growth)

– Need to control salt levels (EC) in the compost.– Avoid organic acids (anaerobic decomposition)



Plant Response versus Age of Composted Plant Response versus Age of Composted Dairy Manure + Straw or SawdustDairy Manure + Straw or Sawdust

Compost Utilization

Natural Disease Suppression in Compost Mixes

Dhaka Bangladesh2008 OSU/OARDC 49Spring et al., 1980, Phytopathology 70:1209-1212

Peat mix Compost Mix

This Phytophthora root rot bioassay helped prove that natural suppression in compost mixes is effective.


Suppressive potting mix used to control root diseases in potted poinsettia plants.

HAJ Hoitink

New Uses for Compost.


Seven-yr-old Taxus crop transplanted at 1-1.5 yr intervals to sustain natural suppression of root rot. Fungicides are not used in spite of its extreme susceptibilty to Phytophthora root rot!!!!

20 gal pots

Compost Utilization


Rhizoctonia web blight in a mix suppressive

to Phytophthora root rot

What about other diseases?Compost Utilization


Suppression of Suppression of RhizoctoniaRhizoctonia

More than 80% of 300 different compost-amended potting mixes tested failed to suppress Rhizoctonia damping-off because specific biocontrol agents failed to colonize the compost naturally!!

The solution is to inoculate potting mixes during formulation with biocontrol agents (egTrichoderma spp.) that destroy Rhizoctonia.


CompostCompost--Induced Systemic Resistance Induced Systemic Resistance (ISR)(ISR)

•• Less than 2% of all types and batches of Less than 2% of all types and batches of composts tested naturally induced ISR. composts tested naturally induced ISR.

•• Specific Specific BacillusBacillus strains and strains and TrichodermaTrichodermaisolates are the most ISRisolates are the most ISR--active active microorganisms in composts.microorganisms in composts.

Krause et al, 2003, Phytopathology 93:1292-1300.

Dhaka Bangladesh2008 OSU/OARDC 55Zhang et al., 1998, Phytopath. 88:450-455

Compost-Induced Systemic Resistance (ISR)


Overall ConclusionsOverall Conclusions•• Compost stability, nitrogen level and absent of Compost stability, nitrogen level and absent of phytotoxicphytotoxic

compounds are important to have quality compost. compounds are important to have quality compost. Valuable nutrient source.Valuable nutrient source.

•• Quality composts can be used to achieveQuality composts can be used to achieve–– Biological control of root diseases Biological control of root diseases -- natural suppression natural suppression

with composts is practiced widely. with composts is practiced widely. –– Specific suppression requires inoculation.Specific suppression requires inoculation.–– Some foliar diseases controllable by ISRSome foliar diseases controllable by ISR--active composts. active composts. –– ISR still is a novel field of science.ISR still is a novel field of science.


Wooster, Ohio

Thank you!

[email protected]

Documents

Challenges and Opportunities in Composting Organic Waste · Composting Organic Waste Harold Keener Food, Agricultural and Biological Engineering ... • Look at what’s happened