Study Of PHAs (polyhydroxyalkanoates)
Production From Activated Sludge
Author(s)
D. He, B. B. Zhang, Y. F. Tsang & H. Chua
Abstract
Sludge deposition is of high concern for managers of wastewater treatment
plants due to limited landfill space and increases in deposition fees. Reduction of
the amount of sludge can benefit a plant’s operational cost. In activated sludge,
numerous bacteria synthesise and accumulate polyhydroxyalkanoates (PHAs).
PHAs can be completely biodegraded to water and carbon dioxide, and have
similar properties to conventional plastic. So, PHAs have been recognized as
good candidates for plastics. Thus, production of PHAs can reduce sludge
amount and also have environmentally-friendly effects. However, their high
price compared with conventional plastics has limited their use in a wide range
of applications. In this study, we optimized conditions to produce PHAs.
Activated sludge bacteria from a conventional wastewater treatment process
were induced to accumulate PHAs under different carbon-nitrogen (C:N) ratios.
Both the highest net cell growth and polymer production yield were achieved
under a C:N ratio of 96. Moreover, carbon source is another important factor in
synthesis. The composition of the polymer accumulated was dependent on the
valeric acid (C5) content in the feed.
Keywords: activated sludge, polyhydroxyalkanoates (PHAs), carbon-nitrogen
ratios, carbon source.
1 Introduction
Plastic materials have become an integral part of contemporary life because of
their many desirable properties, including their duralibity, flexibility and
resistance. However, many artificial polymers are found to be harmful to the
environment due to the non-biodegradable properties, which means they are not
easily decomposed in nature by microorganisms (Huang et al. [1]). So there is a
Keywords
activated sludge, polyhydroxyalkanoates (PHAs), carbon-nitrogen
ratios, carbon source.
Related Book
Other papers in this volume
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