BS ISO 14853:2005 Plastics. Determination of the ultimate anaerobic biodegradation of plastic materials in an aqueous system. Method by measurement of biogas production
BS ISO 14853 specifies a method for the determination of the ultimate anaerobic biodegradability of plastics by anaerobic microorganisms. The conditions described in BS ISO 14853 do not necessarily correspond to the optimum conditions for the maximum degree of biodegradation to occur.
The test calls for exposure of the test material to sludge for a period of up to 60 days, which is longer than the normal sludge retention time (25 to 30 days) in anaerobic digesters, though digesters at industrial sites can have much longer retention times.
The method applies to the following materials:
- Natural and/or synthetic polymers, copolymers or mixtures thereof
- Plastic materials which contain additives such as plasticizers, colorants or other compounds
- Water-soluble polymers
- Materials which, under the test conditions, do not inhibit the microorganisms present in the inoculum.
Inhibitory effects can be determined using an inhibition control or by another appropriate method (see e.g. ISO 13641). If the test material is inhibitory to the inoculum, a lower test concentration, another inoculum or a pre-exposed inoculum can be used.
Contents of BS ISO 14853:
Foreword
Introduction
1 Scope
2 Normative references
3 Terms and definitions
4 Principle
5 Reagents and materials
6 Apparatus
7 Procedure
8 Calculation and expression of results
9 Validity of results
10 Test report
Annex A (informative) Example of apparatus for determining the amount of biogas produced by measuring the increase in gas pressure
Annex B (informative) Example of apparatus for determining volumetrically the amount of biogas produced
Annex C (informative) Example of a biodegradation curve
Annex D (informative) Examples of data sheets for anaerobic biodegradability tests
Annex E (informative) Table of water vapour pressures at various temperatures
Annex F (informative) Calculation of theoretical carbon dioxide (ThCO2) and theoretical methane (ThCH4) production
Annex G (informative) Example of determination of recovery rate
Annex H (informative) Example of a workflow scheme
Bibliography
