EN ISO 11734:1998
(Main)Water quality - Evaluation of the "ultimate" anaerobic biodegradability of organic compounds in digested sludge - Method by measurement of the biogas production (ISO 11734:1995)
General Information
- Abstract
Gives a method for the evaluation of the ultimate biodegradability of organic compounds in digested sludge at a given concentration by anaerobic microorganisms.
- Status
- Published
- Publication Date
- 21-Jul-1998
- Withdrawal Date
- 30-Jan-1999
- Technical Committee
- CEN/TC 230 - Water analysis
- Drafting Committee
- CEN/TC 230 - Water analysis
- Current Stage
- 9093 - Decision to confirm - Review Enquiry
- Start Date
- 21-May-2008
- Completion Date
- 21-May-2008
Overview
EN ISO 11734:1998 (ISO 11734:1995) is a CEN-adopted international standard for water quality testing that defines a laboratory method to evaluate the "ultimate" anaerobic biodegradability of organic compounds in digested sludge. The method determines biodegradability at a given concentration by measuring biogas production generated by anaerobic microorganisms present in sludge. This standard is intended for assessing the extent to which organic substances are mineralized under anaerobic digestion conditions.
Key topics and requirements
The standard addresses the essential elements of an anaerobic biodegradability test, including:
- Test principle - assessment of biodegradation through cumulative biogas (methane/CO2) production as the degradation end-point.
- Use of digested sludge as inoculum - characterisation and preparation of anaerobic microbial inoculum derived from digesters.
- Controls and references - inclusion of procedural blanks and suitable reference compounds to validate test performance.
- Substrate dosing - testing at defined substrate concentrations to evaluate "ultimate" biodegradability rather than short-term conversion.
- Measurement and monitoring - periodic measurement of biogas volume and composition to derive biodegradation curves.
- Data interpretation and reporting - calculation of biodegradation percentages, test validity criteria and clear reporting of results and conditions.
Note: The standard sets procedural and reporting requirements but does not replace site‑specific operational data; it standardizes laboratory evaluation for comparability.
Applications and who uses it
EN ISO 11734:1998 is used where reliable evaluation of anaerobic biodegradability is required:
- Environmental testing laboratories performing regulatory or research biodegradation assays.
- Wastewater treatment and biogas facilities assessing the treatability and methane potential of new wastes or co-substrates.
- Chemical manufacturers and formulators demonstrating environmental fate of organic substances.
- Regulators and permitting authorities evaluating environmental impact and compliance for discharges or sludge acceptance.
- Research and development teams studying anaerobic degradation pathways and sludge management strategies.
This method supports decisions on sludge recycling, anaerobic digester feed suitability, and environmental classification of organic compounds.
Related standards
EN ISO 11734 forms part of broader water quality and biodegradability standardization. Laboratories often use it alongside other ISO/CEN methods for aerobic and anaerobic biodegradation, sludge characterization, and gas analysis to provide a comprehensive assessment of environmental fate and anaerobic treatment performance.
Keywords: anaerobic biodegradability, digested sludge, biogas production, EN ISO 11734, water quality standard, ultimate biodegradability, biodegradation testing.
Relations
- Effective Date
- 25-Aug-2026
- Effective Date
- 25-Aug-2026
- Effective Date
- 28-Jan-2026
Get Certified
Connect with accredited certification bodies for this standard
CIS Institut d.o.o.
Personal Protective Equipment (PPE) certification body. Notified Body NB-2890 for EU Regulation 2016/425 PPE.

Kiwa BDA Testing
Building and construction product certification.
Kmetijski inštitut Slovenije
Agricultural Institute of Slovenia. Soil testing, plant health, agricultural product analysis.
Sponsored listings
Frequently Asked Questions
EN ISO 11734:1998 is a standard published by the European Committee for Standardization (CEN). Its full title is "Water quality - Evaluation of the "ultimate" anaerobic biodegradability of organic compounds in digested sludge - Method by measurement of the biogas production (ISO 11734:1995)". This standard covers: Gives a method for the evaluation of the ultimate biodegradability of organic compounds in digested sludge at a given concentration by anaerobic microorganisms.
Gives a method for the evaluation of the ultimate biodegradability of organic compounds in digested sludge at a given concentration by anaerobic microorganisms.
EN ISO 11734:1998 is classified under the following ICS (International Classification for Standards) categories: 13.060 - Water quality. The ICS classification helps identify the subject area and facilitates finding related standards.
EN ISO 11734:1998 has the following relationships with other standards: It is inter standard links to ISO 11923:1997, ISO 10634:1995, EN 26352:1991. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
EN ISO 11734:1998 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
SLOVENSKI STANDARD
01-marec-1999
1DGRPHãþD
SIST ISO 11734:1998
.DNRYRVWYRGH9UHGQRWHQMHNRQþQHDQDHUREQHELRUD]JUDGOMLYRVWLRUJDQVNLK
VSRMLQYSUHVQRYOMHQHPEODWX0HWRGD]PHUMHQMHPQDVWDOHJDELRSOLQD,62
Water quality - Evaluation of the "ultimate" anaerobic biodegradability of organic
compounds in digested sludge - Method by measurement of the biogas production (ISO
11734:1995)
Wasserbeschaffenheit - Bestimmung der vollständigen anaeroben biologischen
Abbaubarkeit organischer Verbindungen im Faulschlamm - Verfahren durch Messung
der Biogasproduktion (
...



