title: Optimal production of polyhydroxyalkanoates in activated sludge biomass.
abstract: 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%.
authors.affiliation: Department of Civil and Structural Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon, China.
authors.forename: C K
authors.initials: CK
authors.lastname: Ma
authors.forename: H
authors.initials: H
authors.lastname: Chua
authors.forename: P H
authors.initials: PH
authors.lastname: Yu
authors.forename: K
authors.initials: K
authors.lastname: Hong
mesh_terms: D001419:Bacteria / Q000254:growth & development* / Q000302:isolation & purification; D001673:Biodegradation, Environmental; D018533:Biomass; D002244:Carbon; D009584:Nitrogen; D010969:Plastics; D011091:Polyesters / Q000737:chemistry*; D012722:Sewage; D014871:Water Microbiology
chemical_list: D010969:Plastics; D011091:Polyesters; D012722:Sewage; D002244:Carbon; D009584:Nitrogen