Batch production of polyhydroxyalkanoate by low-polyphosphate-content activated sludge at varying pH [An article from: Bioresource Technology]

This digital document is a journal article from Bioresource Technology, published by Elsevier in 2007. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.

Description:
Polyhydroxyalkanoate (PHA), a biodegradable plastic, can be produced from excess activated sludge by utilizing intracellular glycogen and polyphosphate as energy sources under growth-limiting conditions. Activated sludge of 2%, 6%, and 8% polyphosphate with similar glycogen content of 33% was investigated for batch PHA production by varying the pH values from 6 to 8. Acetate applied at 1000mg COD/L was almost exhausted within 80min of anaerobic stage. The remaining glycogen in the sludge was higher at a lower pH because of less energy used for acetate uptake. Highest PHA content of 51% was obtained from sludge with an 8% polyphosphate content at pH 8. PHA production occurred rapidly within the first 20min, with a productivity rate of 2.19g PHA/L-h. The results in this study indicate that PHA production by using activated sludge is a promising alternative to a typical pure culture approach.