Mineralisation anaerobic biodegradation

Figure 2.3 Time-dependent mineralisation (percentage of the theoretical biogas volume) of various polyesters in anaerobic conditions and wastewater sludge at 37 °C over a period of 42 days. (Polyester films 0 = 19 mm surface area 22.7 cm initial film weights 35-40 mg 2 films per test). Reproduced with permission from D.M. Abou-Zeid, Anaerobic Biodegradation of Natural and Synthetic Polyesters, Technical University Braunschweig, Braunschweig, Germany. 2000, Technical University Braunschweig...

Anaerobic tests generally follow biodegradation by measuring the increase in pressure and/or volume due to gas evolution, usually in combination with gas chromatographic analysis of the gas phase [83, 84]. Most aerobic standard tests apply continuous aeration the exit stream of air can be directly analysed continuously using a carbon dioxide monitor (usually infrared detectors) or titrimetrically after sorption in dilute alkali. The cumulative amount of carbon dioxide generated, expressed as a percentage of the theoretically expected value for total conversion to CO2, is a measure for the extent of mineralisation achieved. 

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