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▶ Materials that can be tested:
➢ Plastic materials.
▶ Test substance requirement:
➢ Formula needs to be known in order to calculate the ThOD;
➢ Preferably in powder form with maximum size of 250 um diameter;
➢ Similar shapes of different substances should be used if they are to be compared.
▶ Measurement: oxygen consumption (any type of respirometer is fine as long as the measurement is accurate).
▶ Temperature: 15-25°C.
▶ Reference: a well-defined biodegradable polymer (e.g., microcrystalline cellulose powder or ashless cellulose filters).
▶ Test substance dosage: at least 100 mg/L of the substance, or 170 mg/L of ThOD.
▶ Reactor example: 300 mL of volume with 90 mL of natural seawater only, or natural seawater with 0.1-1 g/L sediment.
▶ Number of reactors: 3 for blank control, 3 for reference control, and 3 for test substance.
▶ Duration: normally up to 1 year; prolong the test up to 2 years if significant biodegradation is still observed after 1 year.
▶ Upon termination, determine pH, nitrate and nitrite to correct the calculated degree of biodegradation for nitrification.
Different testing methods are applicable for materials with different properties. Below is a summary of the applicability of ISO 23977-2. Please check our Method Selection Guide to select the most appropriate method for your materials. You can also find the applicability for many other methods on Aropha Resource Center
|Test||Analytical method||Sample info required *||Poorly soluble||Volatile||Adsorbing|
|ISO 23977-2||Oxygen consumption||ThOD *||+||+||+|
*"Sample info required" is the information needed to calculate the biodegradation percentages. This must be available for a selected method.
*"ThOD" can be easily calculated based on the formula of the sample. Try our Online ThOD Calculator.
To learn more about different types of biodegradation tests, their applicability, biodegradation mechanisms, and many other information such as case studies, publications, and blogs, please check our Aropha Resource Center