Quality assurance of digestate inSwitzerland
Cork / Ireland - September 2011
IEA Bioenergy Task 37
Nathalie BACHMANN
EREP SA | Chemin du Coteau 28 | CH 1123 Aclens - Switzerland
www.erep.ch | [email protected] | +41 (0)21 869 71 42
Traitement et valorisation dedéchets et
d’effluents organiques
Introduction
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90’ies Experiments on impact of digestate on soil and plants
2001 Law on fertilizer marketing
2001 Guideline on quality management of digestate
2003-2006 Study on organic polluants in digestate/ influence ofdigestate on environnement, soil fertility and plant health
2010 Guideline on quality management of digestate
Some key events:
Why do we need a qualityassurance system for digestate?
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Digestate
Liquid digestate
Solid digestate
Compost (aerobic treatment of solid digestate)
Different products, different handling
Correct use leads to a very positive influence on the soil
Agricultural fertiliser (agricultural substrates)
Recycling fertiliser (non agricultural substrates)
Why do we need a qualityassurance system for digestate?
Quality guarantee
• Only high qualityproducts
• Long term soilquality & plant health
• Confidence betweenproducer and user
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Avoid risks
• Avoid negativeimpacts and badreputation of digestate
due to wrongutilisation
Improveunderstanding
• Monitoring and datacollection for globalview and analysis
• Detection of gaps inthe actual knowledge
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How works the qualityassurance system?
VKSAssociation of composting and digestion facilities(Verband Kompost- und Vergärwerke Schweiz)
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VKSAssociation of composting and digestion facilities(Verband Kompost- und Vergärwerke Schweiz)
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Goal:
Improve marked conditions forcompost and digestate
Actions:
Education – quality – controle
Coordination of projects
Influence political desicions (law)
Participation in the elaboration of the quality guideline
Link:
http://www.vks-asic.ch
Inspection commissionARGE Inspektorat
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Inspection bodyARGE Inspektorat
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Goal:
To control the digestate producers
Actions:
On demand of a canton or ofan installation
Visit of the installations, datacollection (once a year or everytwo years)
Update of the database (CVIS)
Inform authorities (canton) about the results
Link:
http://www.compospect.ch
Law, directives and guidelines
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Substrates DigestateBiogas plant
Laws
Positve list Quality guideline for compost and digestate
Two main guidelines:
Directives and guidelines
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Positive list
List of substrates and indication of:
Hygienic classa) no problem
b) attention required
c) special treatment and/or authorisation needed
If appropriate for mesophilic / thermophilic digestion
Special remarks (high salt content, pH, …)
Directives and guidelines
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Directives and guidelines
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Which productfor which
utilisation?
Quality guideline 2010 forcompost and digestate
http://www.compospect.ch/doc/acrobatreader/Q-Richtlinie_2010_def.pdf
Directives and guidelines
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Definition of the quality standards of thedifferent products:
Liquid digestate
Solid digestate
− without composting
− with composting
In function of their utilisation:
Arable farming/ fodder production
Horiculture (indoor and outdoor)
Directives and guidelines
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Quality standards take account of:
- Heavy metals
- Organic polluants
- Foreign matters / impurities (maximum content anddiameter of plastic, glass, metal)
- Hygienic requirements (input criteria, retention timeand temperature in the digester, how to avoidrecontamination)
- Physical and chemical propreties (dry/organicmatter, pH, salt content, C/N, nitrate, nitrite)
Directives and guidelines
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Utilisation and application:
- Which product for which utilisation
- Impacts on soil quality
- Period of application (seasonal, daily andmeteorological conditions)
- How much to apply
- How to apply (technology)
Perspectives
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Long term experiments / «essais-vitrines»- Tests of minimum 5 years- Analysis of the long term effects of digestateunder different conditions (soil, climate, crops):Nutrients, humus content, soil structure, diseasesupression
LogoBased on the guideline for compost and digestate
Training programEstablishment of a unified training and retrainingprogram
Photo: Fibl Schweiz
Thank you for your attention!
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Law
Dir
ecti
ves
an
dg
uid
eli
nes
Digestateproducer
Digestateuser
VKS
Inspection commission /inspectors
Canton
Controlling,consulting,certification
Contract
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Contract
Database (CVIS)
Annual report
VKS : Association of composting and digestion facilities
