Optimal Production of Polyhydroxyalkanoates in Activated Sludge Biomass

  • C. K. Ma
  • H. Chua
  • P. H. F. Yu
  • K. Hong
Part of the Applied Biochemistry and Biotechnology book series (ABAB)


Polyhydroxyalkanoates (PHAs) have been recognized as good candidates for biodegradable plastics, but their high price compared with conventional plastics has limited their use. In this study, activated sludge microorganisms from a conventional wastewater treatment process were induced, by controlling the carbon:nitrogen (C:N) ratio in the reactor liquor, to accumulate PHAs. In addition, an intermittent nitrogen feeding program was established to optimize the volumetric PHA productivity in a wastewater treatment process. The optimal overall polymer production yield of 0.111 g of polymer/g of carbonaceous substrate consumed was achieved under a C:N ratio of 96: 1 by feeding nitrogen in the reactor liquor once every four cycles. At the same time, the amount of excess sludge generated from the wastewater treatment process was reduced by 22.9%.

Index Entries

Activated sludge polyhydroxyalkanoates carbon:nitrogen ratio intermittent nitrogen feeding wastewater treatment 


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Copyright information

© Springer Science+Business Media New York 2000

Authors and Affiliations

  • C. K. Ma
    • 1
  • H. Chua
    • 1
  • P. H. F. Yu
    • 2
  • K. Hong
    • 3
  1. 1.Department of Civil and Structural EngineeringThe Hong Kong Polytechnic UniversityHung Hom, Kowloon, Hong KongChina
  2. 2.Department of Applied Biology and Chemical TechnologyThe Hong Kong Polytechnic UniversityHung Hom, Kowloon, Hong KongChina
  3. 3.Engineering SchoolSouth China University of Tropical AgricultureDanzhou, HainnanChina

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