bokashi composting: performance monitoring presentation to wasteminz conference 16 october 2009 dr...
TRANSCRIPT
Bokashi Composting: Performance Monitoring
Presentation to WasteMINZ Conference16 October 2009
Dr Sean Barnes – Aurecon NZNeville Burt – Bokashi NZ
Summary of Presentation
• Introduction and Research Drivers
• The Bokashi Process
• Our Methodology
• Results and Discussion
• Conclusions
• Where to From Here?
Introduction and Drivers
What is Bokashi?
Bokashi Composting
+
=
Decentralised Waste Treatment
HOUSEHOLDS:
COMMERCIAL:
ON-SITE USECOMMUNITY GARDENS
PARKS/RESERVESAGRICULTURE
The New Bigger Bokashi Bins
What Did We Monitor?
SOLIDS + COMPOST-ZING
LIQUID
BURIAL IN GARDEN/MEDIA
Analysis
• Key Nutrients
• Carbon
• Composition
The Trials
TRIAL 1 TRIAL 2
5 W
EE
KS
What Happened?
TRIAL 1
Composition of Juice
• Varied between trials and over time• Low pH – around 4 to 4.5• High COD (soluble) – 83,000 to 160,000mg/L• Nitrogen (ammonia) – 2,000mg/L +• Phosphorus (organic) – 1,400mg/L & 360mg/L +• Potassium – 2,600mg/L +
• Trends FERM 1 FERM 2
COD Generation
0
50
100
150
200
250
300
350
400
450
500
0 5 10 15 20 25 30 35 40
Time (days)
Cu
mu
lati
ve s
olu
ble
CO
D g
ener
ated
(g
O2)
Ferm2 Ferm1
The Fermentation
• Trial 1 had higher nutrient and COD levels• High juice content from predominantly vegetable
waste in Trial 2 Differences based on feed material
• Juice production = waste volume reduction• Lactic acid production assumed
Liquid fertiliser (after pH adjustment)
Fermentation Microbes
Solid Polymeric Material
Macromolecules (e.g. Starch)
Monomers (e.g. Glucose)
Fermentation Products (e.g. Lactic Acid)
EM Microbes
• Lactic Acid Bacteria
• Photosynthetic Bacteria
• Yeasts
• Actinomycetes
Pathogens
• Faecal Coliforms
• Clostridium sp.
• Staphylococcus sp.
• Salmonella sp.
• Listeria sp.
Microbial Parameters (Liquid)
• High numbers of microbes (aerobic/anaerobic)• Faecal Coliforms and Escherichia coli present in
first sample of Trial 1 only
NO BAD GUYS!• Below Detection Limits Enterobacteriaceae,
Staphylococcus aureus, Clostridium perfringens, Listeria monocytogenes, Salmonella sp.
What Did We Monitor?
SOLIDS + COMPOST-ZING
LIQUID
BURIAL IN GARDEN/MEDIA
Analysis
• Key Nutrients
• Carbon
• Composition
Fermented Food Waste
5 Weeks Composting
Dry basis:
N 2.4% 0.9%
P 0.2% 0.1%
K 0.4% 0.5%
C 30% (Lit)Trial 1 @ 0 Weeks
Post-Burial Analysis (0 to 8 Weeks)
Org Matter:Trial 1: 38.6% to 46.2%Trial 2: 6.1% to 8.5%CTrial 1: 22.4% to 26.8%Trial 2: 3.5% to 4.9%NTrial 1: 1.2% to 1.7%Trial 2: 0.4% to 0.5%PTrial 1: 0.2% to 0.4%Trial 2: 0.2% slight increaseKTrial 1: 0.5% to 0.7%Trial 2: 0.2% to 0.3%
Trial 1 @ 4 Weeks
Conclusions
• Common food pathogens absent in juice samples after fermentation
• No discernable odour• High N, P and K content in juice + low pH• Solid material breaks down rapidly in soil or
compost pile• Further targeted testing of COD composition and
microbes on commercial systems.
Decentralised Waste Treatment
HOUSEHOLDS:
COMMERCIAL:
ON-SITE USECOMMUNITY GARDENS
PARKS/RESERVESAGRICULTURE
Where To From Here?
Waiheke Island – Mudbrick Vineyard, Te Whau Brasserie, Lure Vineyard, Café Get Stuffed
Hamilton (Back to Earth Programme)
Hanmer Springs (Business Association)
Waitakere City (Project Circle)
Standards To Be Met
• Resource Consent Requirements• Work with Regional Councils
• BioGro Certification NZ – NZBPCC
• Standards
The Future: Microsheds/Transition Towns
The Juice (Liquid Product)
0
1000
2000
3000
4000
5000
6000
0 5 10 15 20 25 30 35 40
Time (days)
Cu
mu
lati
ve J
uic
e V
olu
me
(mL
)
Ferm 1 Ferm 2